Mercurial > hg > truffle
annotate src/os_cpu/linux_x86/vm/os_linux_x86.cpp @ 52:75b0f3cb1943
Merge
| author | dcubed |
|---|---|
| date | Thu, 13 Mar 2008 14:17:48 -0700 |
| parents | e195fe4c40c7 485d403e94e1 |
| children | d1605aabd0a1 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 * Copyright 1999-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 // do not include precompiled header file | |
| 26 # include "incls/_os_linux_x86.cpp.incl" | |
| 27 | |
| 28 // put OS-includes here | |
| 29 # include <sys/types.h> | |
| 30 # include <sys/mman.h> | |
| 31 # include <pthread.h> | |
| 32 # include <signal.h> | |
| 33 # include <errno.h> | |
| 34 # include <dlfcn.h> | |
| 35 # include <stdlib.h> | |
| 36 # include <stdio.h> | |
| 37 # include <unistd.h> | |
| 38 # include <sys/resource.h> | |
| 39 # include <pthread.h> | |
| 40 # include <sys/stat.h> | |
| 41 # include <sys/time.h> | |
| 42 # include <sys/utsname.h> | |
| 43 # include <sys/socket.h> | |
| 44 # include <sys/wait.h> | |
| 45 # include <pwd.h> | |
| 46 # include <poll.h> | |
| 47 # include <ucontext.h> | |
| 48 # include <fpu_control.h> | |
| 49 | |
| 50 #ifdef AMD64 | |
| 51 #define REG_SP REG_RSP | |
| 52 #define REG_PC REG_RIP | |
| 53 #define REG_FP REG_RBP | |
| 54 #define SPELL_REG_SP "rsp" | |
| 55 #define SPELL_REG_FP "rbp" | |
| 56 #else | |
| 57 #define REG_SP REG_UESP | |
| 58 #define REG_PC REG_EIP | |
| 59 #define REG_FP REG_EBP | |
| 60 #define SPELL_REG_SP "esp" | |
| 61 #define SPELL_REG_FP "ebp" | |
| 62 #endif // AMD64 | |
| 63 | |
| 64 address os::current_stack_pointer() { | |
|
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65 #ifdef SPARC_WORKS |
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66 register void *esp; |
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67 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); |
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68 return (address) ((char*)esp + sizeof(long)*2); |
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69 #else |
| 0 | 70 register void *esp __asm__ (SPELL_REG_SP); |
| 71 return (address) esp; | |
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72 #endif |
| 0 | 73 } |
| 74 | |
| 75 char* os::non_memory_address_word() { | |
| 76 // Must never look like an address returned by reserve_memory, | |
| 77 // even in its subfields (as defined by the CPU immediate fields, | |
| 78 // if the CPU splits constants across multiple instructions). | |
| 79 | |
| 80 return (char*) -1; | |
| 81 } | |
| 82 | |
| 83 void os::initialize_thread() { | |
| 84 // Nothing to do. | |
| 85 } | |
| 86 | |
| 87 address os::Linux::ucontext_get_pc(ucontext_t * uc) { | |
| 88 return (address)uc->uc_mcontext.gregs[REG_PC]; | |
| 89 } | |
| 90 | |
| 91 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) { | |
| 92 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP]; | |
| 93 } | |
| 94 | |
| 95 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) { | |
| 96 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP]; | |
| 97 } | |
| 98 | |
| 99 // For Forte Analyzer AsyncGetCallTrace profiling support - thread | |
| 100 // is currently interrupted by SIGPROF. | |
| 101 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal | |
| 102 // frames. Currently we don't do that on Linux, so it's the same as | |
| 103 // os::fetch_frame_from_context(). | |
| 104 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread, | |
| 105 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { | |
| 106 | |
| 107 assert(thread != NULL, "just checking"); | |
| 108 assert(ret_sp != NULL, "just checking"); | |
| 109 assert(ret_fp != NULL, "just checking"); | |
| 110 | |
| 111 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); | |
| 112 } | |
| 113 | |
| 114 ExtendedPC os::fetch_frame_from_context(void* ucVoid, | |
| 115 intptr_t** ret_sp, intptr_t** ret_fp) { | |
| 116 | |
| 117 ExtendedPC epc; | |
| 118 ucontext_t* uc = (ucontext_t*)ucVoid; | |
| 119 | |
| 120 if (uc != NULL) { | |
| 121 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc)); | |
| 122 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc); | |
| 123 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc); | |
| 124 } else { | |
| 125 // construct empty ExtendedPC for return value checking | |
| 126 epc = ExtendedPC(NULL); | |
| 127 if (ret_sp) *ret_sp = (intptr_t *)NULL; | |
| 128 if (ret_fp) *ret_fp = (intptr_t *)NULL; | |
| 129 } | |
| 130 | |
| 131 return epc; | |
| 132 } | |
| 133 | |
| 134 frame os::fetch_frame_from_context(void* ucVoid) { | |
| 135 intptr_t* sp; | |
| 136 intptr_t* fp; | |
| 137 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); | |
| 138 return frame(sp, fp, epc.pc()); | |
| 139 } | |
| 140 | |
| 141 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get | |
| 142 // turned off by -fomit-frame-pointer, | |
| 143 frame os::get_sender_for_C_frame(frame* fr) { | |
| 144 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); | |
| 145 } | |
| 146 | |
| 147 intptr_t* _get_previous_fp() { | |
|
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148 #ifdef SPARC_WORKS |
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149 register intptr_t **ebp; |
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150 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); |
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151 #else |
| 0 | 152 register intptr_t **ebp __asm__ (SPELL_REG_FP); |
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153 #endif |
| 0 | 154 return (intptr_t*) *ebp; // we want what it points to. |
| 155 } | |
| 156 | |
| 157 | |
| 158 frame os::current_frame() { | |
| 159 intptr_t* fp = _get_previous_fp(); | |
| 160 frame myframe((intptr_t*)os::current_stack_pointer(), | |
| 161 (intptr_t*)fp, | |
| 162 CAST_FROM_FN_PTR(address, os::current_frame)); | |
| 163 if (os::is_first_C_frame(&myframe)) { | |
| 164 // stack is not walkable | |
| 165 return frame(NULL, NULL, NULL); | |
| 166 } else { | |
| 167 return os::get_sender_for_C_frame(&myframe); | |
| 168 } | |
| 169 } | |
| 170 | |
| 171 // Utility functions | |
| 172 | |
| 173 // From IA32 System Programming Guide | |
| 174 enum { | |
| 175 trap_page_fault = 0xE | |
| 176 }; | |
| 177 | |
| 178 extern "C" void Fetch32PFI () ; | |
| 179 extern "C" void Fetch32Resume () ; | |
| 180 #ifdef AMD64 | |
| 181 extern "C" void FetchNPFI () ; | |
| 182 extern "C" void FetchNResume () ; | |
| 183 #endif // AMD64 | |
| 184 | |
| 185 extern "C" int | |
| 186 JVM_handle_linux_signal(int sig, | |
| 187 siginfo_t* info, | |
| 188 void* ucVoid, | |
| 189 int abort_if_unrecognized) { | |
| 190 ucontext_t* uc = (ucontext_t*) ucVoid; | |
| 191 | |
| 192 Thread* t = ThreadLocalStorage::get_thread_slow(); | |
| 193 | |
| 194 SignalHandlerMark shm(t); | |
| 195 | |
| 196 // Note: it's not uncommon that JNI code uses signal/sigset to install | |
| 197 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, | |
| 198 // or have a SIGILL handler when detecting CPU type). When that happens, | |
| 199 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To | |
| 200 // avoid unnecessary crash when libjsig is not preloaded, try handle signals | |
| 201 // that do not require siginfo/ucontext first. | |
| 202 | |
| 203 if (sig == SIGPIPE || sig == SIGXFSZ) { | |
| 204 // allow chained handler to go first | |
| 205 if (os::Linux::chained_handler(sig, info, ucVoid)) { | |
| 206 return true; | |
| 207 } else { | |
| 208 if (PrintMiscellaneous && (WizardMode || Verbose)) { | |
| 209 char buf[64]; | |
| 210 warning("Ignoring %s - see bugs 4229104 or 646499219", | |
| 211 os::exception_name(sig, buf, sizeof(buf))); | |
| 212 } | |
| 213 return true; | |
| 214 } | |
| 215 } | |
| 216 | |
| 217 JavaThread* thread = NULL; | |
| 218 VMThread* vmthread = NULL; | |
| 219 if (os::Linux::signal_handlers_are_installed) { | |
| 220 if (t != NULL ){ | |
| 221 if(t->is_Java_thread()) { | |
| 222 thread = (JavaThread*)t; | |
| 223 } | |
| 224 else if(t->is_VM_thread()){ | |
| 225 vmthread = (VMThread *)t; | |
| 226 } | |
| 227 } | |
| 228 } | |
| 229 /* | |
| 230 NOTE: does not seem to work on linux. | |
| 231 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { | |
| 232 // can't decode this kind of signal | |
| 233 info = NULL; | |
| 234 } else { | |
| 235 assert(sig == info->si_signo, "bad siginfo"); | |
| 236 } | |
| 237 */ | |
| 238 // decide if this trap can be handled by a stub | |
| 239 address stub = NULL; | |
| 240 | |
| 241 address pc = NULL; | |
| 242 | |
| 243 //%note os_trap_1 | |
| 244 if (info != NULL && uc != NULL && thread != NULL) { | |
| 245 pc = (address) os::Linux::ucontext_get_pc(uc); | |
| 246 | |
| 247 if (pc == (address) Fetch32PFI) { | |
| 248 uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ; | |
| 249 return 1 ; | |
| 250 } | |
| 251 #ifdef AMD64 | |
| 252 if (pc == (address) FetchNPFI) { | |
| 253 uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ; | |
| 254 return 1 ; | |
| 255 } | |
| 256 #endif // AMD64 | |
| 257 | |
| 258 // Handle ALL stack overflow variations here | |
| 259 if (sig == SIGSEGV) { | |
| 260 address addr = (address) info->si_addr; | |
| 261 | |
| 262 // check if fault address is within thread stack | |
| 263 if (addr < thread->stack_base() && | |
| 264 addr >= thread->stack_base() - thread->stack_size()) { | |
| 265 // stack overflow | |
| 266 if (thread->in_stack_yellow_zone(addr)) { | |
| 267 thread->disable_stack_yellow_zone(); | |
| 268 if (thread->thread_state() == _thread_in_Java) { | |
| 269 // Throw a stack overflow exception. Guard pages will be reenabled | |
| 270 // while unwinding the stack. | |
| 271 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); | |
| 272 } else { | |
| 273 // Thread was in the vm or native code. Return and try to finish. | |
| 274 return 1; | |
| 275 } | |
| 276 } else if (thread->in_stack_red_zone(addr)) { | |
| 277 // Fatal red zone violation. Disable the guard pages and fall through | |
| 278 // to handle_unexpected_exception way down below. | |
| 279 thread->disable_stack_red_zone(); | |
| 280 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); | |
| 281 } else { | |
| 282 // Accessing stack address below sp may cause SEGV if current | |
| 283 // thread has MAP_GROWSDOWN stack. This should only happen when | |
| 284 // current thread was created by user code with MAP_GROWSDOWN flag | |
| 285 // and then attached to VM. See notes in os_linux.cpp. | |
| 286 if (thread->osthread()->expanding_stack() == 0) { | |
| 287 thread->osthread()->set_expanding_stack(); | |
| 288 if (os::Linux::manually_expand_stack(thread, addr)) { | |
| 289 thread->osthread()->clear_expanding_stack(); | |
| 290 return 1; | |
| 291 } | |
| 292 thread->osthread()->clear_expanding_stack(); | |
| 293 } else { | |
| 294 fatal("recursive segv. expanding stack."); | |
| 295 } | |
| 296 } | |
| 297 } | |
| 298 } | |
| 299 | |
| 300 if (thread->thread_state() == _thread_in_Java) { | |
| 301 // Java thread running in Java code => find exception handler if any | |
| 302 // a fault inside compiled code, the interpreter, or a stub | |
| 303 | |
| 304 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) { | |
| 305 stub = SharedRuntime::get_poll_stub(pc); | |
| 306 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { | |
| 307 // BugId 4454115: A read from a MappedByteBuffer can fault | |
| 308 // here if the underlying file has been truncated. | |
| 309 // Do not crash the VM in such a case. | |
| 310 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); | |
| 311 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; | |
| 312 if (nm != NULL && nm->has_unsafe_access()) { | |
| 313 stub = StubRoutines::handler_for_unsafe_access(); | |
| 314 } | |
| 315 } | |
| 316 else | |
| 317 | |
| 318 #ifdef AMD64 | |
| 319 if (sig == SIGFPE && | |
| 320 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { | |
| 321 stub = | |
| 322 SharedRuntime:: | |
| 323 continuation_for_implicit_exception(thread, | |
| 324 pc, | |
| 325 SharedRuntime:: | |
| 326 IMPLICIT_DIVIDE_BY_ZERO); | |
| 327 #else | |
| 328 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { | |
| 329 // HACK: si_code does not work on linux 2.2.12-20!!! | |
| 330 int op = pc[0]; | |
| 331 if (op == 0xDB) { | |
| 332 // FIST | |
| 333 // TODO: The encoding of D2I in i486.ad can cause an exception | |
| 334 // prior to the fist instruction if there was an invalid operation | |
| 335 // pending. We want to dismiss that exception. From the win_32 | |
| 336 // side it also seems that if it really was the fist causing | |
| 337 // the exception that we do the d2i by hand with different | |
| 338 // rounding. Seems kind of weird. | |
| 339 // NOTE: that we take the exception at the NEXT floating point instruction. | |
| 340 assert(pc[0] == 0xDB, "not a FIST opcode"); | |
| 341 assert(pc[1] == 0x14, "not a FIST opcode"); | |
| 342 assert(pc[2] == 0x24, "not a FIST opcode"); | |
| 343 return true; | |
| 344 } else if (op == 0xF7) { | |
| 345 // IDIV | |
| 346 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); | |
| 347 } else { | |
| 348 // TODO: handle more cases if we are using other x86 instructions | |
| 349 // that can generate SIGFPE signal on linux. | |
| 350 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); | |
| 351 fatal("please update this code."); | |
| 352 } | |
| 353 #endif // AMD64 | |
| 354 } else if (sig == SIGSEGV && | |
| 355 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { | |
| 356 // Determination of interpreter/vtable stub/compiled code null exception | |
| 357 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); | |
| 358 } | |
| 359 } else if (thread->thread_state() == _thread_in_vm && | |
| 360 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ | |
| 361 thread->doing_unsafe_access()) { | |
| 362 stub = StubRoutines::handler_for_unsafe_access(); | |
| 363 } | |
| 364 | |
| 365 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in | |
| 366 // and the heap gets shrunk before the field access. | |
| 367 if ((sig == SIGSEGV) || (sig == SIGBUS)) { | |
| 368 address addr = JNI_FastGetField::find_slowcase_pc(pc); | |
| 369 if (addr != (address)-1) { | |
| 370 stub = addr; | |
| 371 } | |
| 372 } | |
| 373 | |
| 374 // Check to see if we caught the safepoint code in the | |
| 375 // process of write protecting the memory serialization page. | |
| 376 // It write enables the page immediately after protecting it | |
| 377 // so we can just return to retry the write. | |
| 378 if ((sig == SIGSEGV) && | |
| 379 os::is_memory_serialize_page(thread, (address) info->si_addr)) { | |
| 380 // Block current thread until the memory serialize page permission restored. | |
| 381 os::block_on_serialize_page_trap(); | |
| 382 return true; | |
| 383 } | |
| 384 } | |
| 385 | |
| 386 #ifndef AMD64 | |
| 387 // Execution protection violation | |
| 388 // | |
| 389 // This should be kept as the last step in the triage. We don't | |
| 390 // have a dedicated trap number for a no-execute fault, so be | |
| 391 // conservative and allow other handlers the first shot. | |
| 392 // | |
| 393 // Note: We don't test that info->si_code == SEGV_ACCERR here. | |
| 394 // this si_code is so generic that it is almost meaningless; and | |
| 395 // the si_code for this condition may change in the future. | |
| 396 // Furthermore, a false-positive should be harmless. | |
| 397 if (UnguardOnExecutionViolation > 0 && | |
| 398 (sig == SIGSEGV || sig == SIGBUS) && | |
| 399 uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) { | |
| 400 int page_size = os::vm_page_size(); | |
| 401 address addr = (address) info->si_addr; | |
| 402 address pc = os::Linux::ucontext_get_pc(uc); | |
| 403 // Make sure the pc and the faulting address are sane. | |
| 404 // | |
| 405 // If an instruction spans a page boundary, and the page containing | |
| 406 // the beginning of the instruction is executable but the following | |
| 407 // page is not, the pc and the faulting address might be slightly | |
| 408 // different - we still want to unguard the 2nd page in this case. | |
| 409 // | |
| 410 // 15 bytes seems to be a (very) safe value for max instruction size. | |
| 411 bool pc_is_near_addr = | |
| 412 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); | |
| 413 bool instr_spans_page_boundary = | |
| 414 (align_size_down((intptr_t) pc ^ (intptr_t) addr, | |
| 415 (intptr_t) page_size) > 0); | |
| 416 | |
| 417 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { | |
| 418 static volatile address last_addr = | |
| 419 (address) os::non_memory_address_word(); | |
| 420 | |
| 421 // In conservative mode, don't unguard unless the address is in the VM | |
| 422 if (addr != last_addr && | |
| 423 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { | |
| 424 | |
| 425 // Unguard and retry | |
| 426 address page_start = | |
| 427 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); | |
| 428 bool res = os::unguard_memory((char*) page_start, page_size); | |
| 429 | |
| 430 if (PrintMiscellaneous && Verbose) { | |
| 431 char buf[256]; | |
| 432 jio_snprintf(buf, sizeof(buf), "Execution protection violation " | |
| 433 "at " INTPTR_FORMAT | |
| 434 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, | |
| 435 page_start, (res ? "success" : "failed"), errno); | |
| 436 tty->print_raw_cr(buf); | |
| 437 } | |
| 438 stub = pc; | |
| 439 | |
| 440 // Set last_addr so if we fault again at the same address, we don't end | |
| 441 // up in an endless loop. | |
| 442 // | |
| 443 // There are two potential complications here. Two threads trapping at | |
| 444 // the same address at the same time could cause one of the threads to | |
| 445 // think it already unguarded, and abort the VM. Likely very rare. | |
| 446 // | |
| 447 // The other race involves two threads alternately trapping at | |
| 448 // different addresses and failing to unguard the page, resulting in | |
| 449 // an endless loop. This condition is probably even more unlikely than | |
| 450 // the first. | |
| 451 // | |
| 452 // Although both cases could be avoided by using locks or thread local | |
| 453 // last_addr, these solutions are unnecessary complication: this | |
| 454 // handler is a best-effort safety net, not a complete solution. It is | |
| 455 // disabled by default and should only be used as a workaround in case | |
| 456 // we missed any no-execute-unsafe VM code. | |
| 457 | |
| 458 last_addr = addr; | |
| 459 } | |
| 460 } | |
| 461 } | |
| 462 #endif // !AMD64 | |
| 463 | |
| 464 if (stub != NULL) { | |
| 465 // save all thread context in case we need to restore it | |
| 466 if (thread != NULL) thread->set_saved_exception_pc(pc); | |
| 467 | |
| 468 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub; | |
| 469 return true; | |
| 470 } | |
| 471 | |
| 472 // signal-chaining | |
| 473 if (os::Linux::chained_handler(sig, info, ucVoid)) { | |
| 474 return true; | |
| 475 } | |
| 476 | |
| 477 if (!abort_if_unrecognized) { | |
| 478 // caller wants another chance, so give it to him | |
| 479 return false; | |
| 480 } | |
| 481 | |
| 482 if (pc == NULL && uc != NULL) { | |
| 483 pc = os::Linux::ucontext_get_pc(uc); | |
| 484 } | |
| 485 | |
| 486 // unmask current signal | |
| 487 sigset_t newset; | |
| 488 sigemptyset(&newset); | |
| 489 sigaddset(&newset, sig); | |
| 490 sigprocmask(SIG_UNBLOCK, &newset, NULL); | |
| 491 | |
| 492 VMError err(t, sig, pc, info, ucVoid); | |
| 493 err.report_and_die(); | |
| 494 | |
| 495 ShouldNotReachHere(); | |
| 496 } | |
| 497 | |
| 498 void os::Linux::init_thread_fpu_state(void) { | |
| 499 #ifndef AMD64 | |
| 500 // set fpu to 53 bit precision | |
| 501 set_fpu_control_word(0x27f); | |
| 502 #endif // !AMD64 | |
| 503 } | |
| 504 | |
| 505 int os::Linux::get_fpu_control_word(void) { | |
| 506 #ifdef AMD64 | |
| 507 return 0; | |
| 508 #else | |
| 509 int fpu_control; | |
| 510 _FPU_GETCW(fpu_control); | |
| 511 return fpu_control & 0xffff; | |
| 512 #endif // AMD64 | |
| 513 } | |
| 514 | |
| 515 void os::Linux::set_fpu_control_word(int fpu_control) { | |
| 516 #ifndef AMD64 | |
| 517 _FPU_SETCW(fpu_control); | |
| 518 #endif // !AMD64 | |
| 519 } | |
| 520 | |
| 521 // Check that the linux kernel version is 2.4 or higher since earlier | |
| 522 // versions do not support SSE without patches. | |
| 523 bool os::supports_sse() { | |
| 524 #ifdef AMD64 | |
| 525 return true; | |
| 526 #else | |
| 527 struct utsname uts; | |
| 528 if( uname(&uts) != 0 ) return false; // uname fails? | |
| 529 char *minor_string; | |
| 530 int major = strtol(uts.release,&minor_string,10); | |
| 531 int minor = strtol(minor_string+1,NULL,10); | |
| 532 bool result = (major > 2 || (major==2 && minor >= 4)); | |
| 533 #ifndef PRODUCT | |
| 534 if (PrintMiscellaneous && Verbose) { | |
| 535 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n", | |
| 536 major,minor, result ? "DOES" : "does NOT"); | |
| 537 } | |
| 538 #endif | |
| 539 return result; | |
| 540 #endif // AMD64 | |
| 541 } | |
| 542 | |
| 543 bool os::is_allocatable(size_t bytes) { | |
| 544 #ifdef AMD64 | |
| 545 // unused on amd64? | |
| 546 return true; | |
| 547 #else | |
| 548 | |
| 549 if (bytes < 2 * G) { | |
| 550 return true; | |
| 551 } | |
| 552 | |
| 553 char* addr = reserve_memory(bytes, NULL); | |
| 554 | |
| 555 if (addr != NULL) { | |
| 556 release_memory(addr, bytes); | |
| 557 } | |
| 558 | |
| 559 return addr != NULL; | |
| 560 #endif // AMD64 | |
| 561 } | |
| 562 | |
| 563 //////////////////////////////////////////////////////////////////////////////// | |
| 564 // thread stack | |
| 565 | |
| 566 #ifdef AMD64 | |
| 567 size_t os::Linux::min_stack_allowed = 64 * K; | |
| 568 | |
| 569 // amd64: pthread on amd64 is always in floating stack mode | |
| 570 bool os::Linux::supports_variable_stack_size() { return true; } | |
| 571 #else | |
| 572 size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; | |
| 573 | |
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574 #ifdef __GNUC__ |
| 0 | 575 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) |
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576 #endif |
| 0 | 577 |
| 578 // Test if pthread library can support variable thread stack size. LinuxThreads | |
| 579 // in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads | |
| 580 // in floating stack mode and NPTL support variable stack size. | |
| 581 bool os::Linux::supports_variable_stack_size() { | |
| 582 if (os::Linux::is_NPTL()) { | |
| 583 // NPTL, yes | |
| 584 return true; | |
| 585 | |
| 586 } else { | |
| 587 // Note: We can't control default stack size when creating a thread. | |
| 588 // If we use non-default stack size (pthread_attr_setstacksize), both | |
| 589 // floating stack and non-floating stack LinuxThreads will return the | |
| 590 // same value. This makes it impossible to implement this function by | |
| 591 // detecting thread stack size directly. | |
| 592 // | |
| 593 // An alternative approach is to check %gs. Fixed-stack LinuxThreads | |
| 594 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use | |
| 595 // %gs (either as LDT selector or GDT selector, depending on kernel) | |
| 596 // to access thread specific data. | |
| 597 // | |
| 598 // Note that %gs is a reserved glibc register since early 2001, so | |
| 599 // applications are not allowed to change its value (Ulrich Drepper from | |
| 600 // Redhat confirmed that all known offenders have been modified to use | |
| 601 // either %fs or TSD). In the worst case scenario, when VM is embedded in | |
| 602 // a native application that plays with %gs, we might see non-zero %gs | |
| 603 // even LinuxThreads is running in fixed stack mode. As the result, we'll | |
| 604 // return true and skip _thread_safety_check(), so we may not be able to | |
| 605 // detect stack-heap collisions. But otherwise it's harmless. | |
| 606 // | |
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607 #ifdef __GNUC__ |
| 0 | 608 return (GET_GS() != 0); |
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609 #else |
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610 return false; |
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611 #endif |
| 0 | 612 } |
| 613 } | |
| 614 #endif // AMD64 | |
| 615 | |
| 616 // return default stack size for thr_type | |
| 617 size_t os::Linux::default_stack_size(os::ThreadType thr_type) { | |
| 618 // default stack size (compiler thread needs larger stack) | |
| 619 #ifdef AMD64 | |
| 620 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); | |
| 621 #else | |
| 622 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); | |
| 623 #endif // AMD64 | |
| 624 return s; | |
| 625 } | |
| 626 | |
| 627 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { | |
| 628 // Creating guard page is very expensive. Java thread has HotSpot | |
| 629 // guard page, only enable glibc guard page for non-Java threads. | |
| 630 return (thr_type == java_thread ? 0 : page_size()); | |
| 631 } | |
| 632 | |
| 633 // Java thread: | |
| 634 // | |
| 635 // Low memory addresses | |
| 636 // +------------------------+ | |
| 637 // | |\ JavaThread created by VM does not have glibc | |
| 638 // | glibc guard page | - guard, attached Java thread usually has | |
| 639 // | |/ 1 page glibc guard. | |
| 640 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() | |
| 641 // | |\ | |
| 642 // | HotSpot Guard Pages | - red and yellow pages | |
| 643 // | |/ | |
| 644 // +------------------------+ JavaThread::stack_yellow_zone_base() | |
| 645 // | |\ | |
| 646 // | Normal Stack | - | |
| 647 // | |/ | |
| 648 // P2 +------------------------+ Thread::stack_base() | |
| 649 // | |
| 650 // Non-Java thread: | |
| 651 // | |
| 652 // Low memory addresses | |
| 653 // +------------------------+ | |
| 654 // | |\ | |
| 655 // | glibc guard page | - usually 1 page | |
| 656 // | |/ | |
| 657 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() | |
| 658 // | |\ | |
| 659 // | Normal Stack | - | |
| 660 // | |/ | |
| 661 // P2 +------------------------+ Thread::stack_base() | |
| 662 // | |
| 663 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from | |
| 664 // pthread_attr_getstack() | |
| 665 | |
| 666 static void current_stack_region(address * bottom, size_t * size) { | |
| 667 if (os::Linux::is_initial_thread()) { | |
| 668 // initial thread needs special handling because pthread_getattr_np() | |
| 669 // may return bogus value. | |
| 670 *bottom = os::Linux::initial_thread_stack_bottom(); | |
| 671 *size = os::Linux::initial_thread_stack_size(); | |
| 672 } else { | |
| 673 pthread_attr_t attr; | |
| 674 | |
| 675 int rslt = pthread_getattr_np(pthread_self(), &attr); | |
| 676 | |
| 677 // JVM needs to know exact stack location, abort if it fails | |
| 678 if (rslt != 0) { | |
| 679 if (rslt == ENOMEM) { | |
| 680 vm_exit_out_of_memory(0, "pthread_getattr_np"); | |
| 681 } else { | |
| 682 fatal1("pthread_getattr_np failed with errno = %d", rslt); | |
| 683 } | |
| 684 } | |
| 685 | |
| 686 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { | |
| 687 fatal("Can not locate current stack attributes!"); | |
| 688 } | |
| 689 | |
| 690 pthread_attr_destroy(&attr); | |
| 691 | |
| 692 } | |
| 693 assert(os::current_stack_pointer() >= *bottom && | |
| 694 os::current_stack_pointer() < *bottom + *size, "just checking"); | |
| 695 } | |
| 696 | |
| 697 address os::current_stack_base() { | |
| 698 address bottom; | |
| 699 size_t size; | |
| 700 current_stack_region(&bottom, &size); | |
| 701 return (bottom + size); | |
| 702 } | |
| 703 | |
| 704 size_t os::current_stack_size() { | |
| 705 // stack size includes normal stack and HotSpot guard pages | |
| 706 address bottom; | |
| 707 size_t size; | |
| 708 current_stack_region(&bottom, &size); | |
| 709 return size; | |
| 710 } | |
| 711 | |
| 712 ///////////////////////////////////////////////////////////////////////////// | |
| 713 // helper functions for fatal error handler | |
| 714 | |
| 715 void os::print_context(outputStream *st, void *context) { | |
| 716 if (context == NULL) return; | |
| 717 | |
| 718 ucontext_t *uc = (ucontext_t*)context; | |
| 719 st->print_cr("Registers:"); | |
| 720 #ifdef AMD64 | |
| 721 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]); | |
| 722 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]); | |
| 723 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]); | |
| 724 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]); | |
| 725 st->cr(); | |
| 726 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]); | |
| 727 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]); | |
| 728 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]); | |
| 729 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]); | |
| 730 st->cr(); | |
| 731 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]); | |
| 732 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]); | |
| 733 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]); | |
| 734 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]); | |
| 735 st->cr(); | |
| 736 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]); | |
| 737 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]); | |
| 738 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]); | |
| 739 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]); | |
| 740 st->cr(); | |
| 741 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]); | |
| 742 st->print(", EFL=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); | |
| 743 st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]); | |
| 744 st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]); | |
| 745 st->cr(); | |
| 746 st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]); | |
| 747 #else | |
| 748 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]); | |
| 749 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]); | |
| 750 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]); | |
| 751 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]); | |
| 752 st->cr(); | |
| 753 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]); | |
| 754 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]); | |
| 755 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]); | |
| 756 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]); | |
| 757 st->cr(); | |
| 758 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]); | |
| 759 st->print(", CR2=" INTPTR_FORMAT, uc->uc_mcontext.cr2); | |
| 760 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); | |
| 761 #endif // AMD64 | |
| 762 st->cr(); | |
| 763 st->cr(); | |
| 764 | |
| 765 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); | |
| 766 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); | |
| 767 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); | |
| 768 st->cr(); | |
| 769 | |
| 770 // Note: it may be unsafe to inspect memory near pc. For example, pc may | |
| 771 // point to garbage if entry point in an nmethod is corrupted. Leave | |
| 772 // this at the end, and hope for the best. | |
| 773 address pc = os::Linux::ucontext_get_pc(uc); | |
| 774 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); | |
| 775 print_hex_dump(st, pc - 16, pc + 16, sizeof(char)); | |
| 776 } | |
| 777 | |
| 778 void os::setup_fpu() { | |
| 779 #ifndef AMD64 | |
| 780 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); | |
| 781 __asm__ volatile ( "fldcw (%0)" : | |
| 782 : "r" (fpu_cntrl) : "memory"); | |
| 783 #endif // !AMD64 | |
| 784 } |