1 /* 2 * Copyright (c) 1999, 2014, 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 #include "utilities/globalDefinitions.hpp" 26 #include "prims/jvm.h" 27 #include "runtime/frame.inline.hpp" 28 #include "runtime/interfaceSupport.hpp" 29 #include "runtime/os.hpp" 30 #include "utilities/vmError.hpp" 31 32 #include <signal.h> 33 #include <unistd.h> 34 #include <sys/resource.h> 35 #include <sys/utsname.h> 36 #include <pthread.h> 37 #include <signal.h> 38 39 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 40 41 // Todo: provide a os::get_max_process_id() or similar. Number of processes 42 // may have been configured, can be read more accurately from proc fs etc. 43 #ifndef MAX_PID 44 #define MAX_PID INT_MAX 45 #endif 46 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID) 47 48 // Check core dump limit and report possible place where core can be found 49 void os::check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize) { 50 int n; 51 struct rlimit rlim; 52 bool success; 53 54 n = get_core_path(buffer, bufferSize); 55 56 if (getrlimit(RLIMIT_CORE, &rlim) != 0) { 57 jio_snprintf(buffer + n, bufferSize - n, "/core or core.%d (may not exist)", current_process_id()); 58 success = true; 59 } else { 60 switch(rlim.rlim_cur) { 61 case RLIM_INFINITY: 62 jio_snprintf(buffer + n, bufferSize - n, "/core or core.%d", current_process_id()); 63 success = true; 64 break; 65 case 0: 66 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again"); 67 success = false; 68 break; 69 default: 70 jio_snprintf(buffer + n, bufferSize - n, "/core or core.%d (max size %lu kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", current_process_id(), (unsigned long)(rlim.rlim_cur >> 10)); 71 success = true; 72 break; 73 } 74 } 75 VMError::report_coredump_status(buffer, success); 76 } 77 78 int os::get_native_stack(address* stack, int frames, int toSkip) { 79 #ifdef _NMT_NOINLINE_ 80 toSkip++; 81 #endif 82 83 int frame_idx = 0; 84 int num_of_frames; // number of frames captured 85 frame fr = os::current_frame(); 86 while (fr.pc() && frame_idx < frames) { 87 if (toSkip > 0) { 88 toSkip --; 89 } else { 90 stack[frame_idx ++] = fr.pc(); 91 } 92 if (fr.fp() == NULL || fr.cb() != NULL || 93 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break; 94 95 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) { 96 fr = os::get_sender_for_C_frame(&fr); 97 } else { 98 break; 99 } 100 } 101 num_of_frames = frame_idx; 102 for (; frame_idx < frames; frame_idx ++) { 103 stack[frame_idx] = NULL; 104 } 105 106 return num_of_frames; 107 } 108 109 110 bool os::unsetenv(const char* name) { 111 assert(name != NULL, "Null pointer"); 112 return (::unsetenv(name) == 0); 113 } 114 115 int os::get_last_error() { 116 return errno; 117 } 118 119 bool os::is_debugger_attached() { 120 // not implemented 121 return false; 122 } 123 124 void os::wait_for_keypress_at_exit(void) { 125 // don't do anything on posix platforms 126 return; 127 } 128 129 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED, 130 // so on posix, unmap the section at the start and at the end of the chunk that we mapped 131 // rather than unmapping and remapping the whole chunk to get requested alignment. 132 char* os::reserve_memory_aligned(size_t size, size_t alignment) { 133 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0, 134 "Alignment must be a multiple of allocation granularity (page size)"); 135 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned"); 136 137 size_t extra_size = size + alignment; 138 assert(extra_size >= size, "overflow, size is too large to allow alignment"); 139 140 char* extra_base = os::reserve_memory(extra_size, NULL, alignment); 141 142 if (extra_base == NULL) { 143 return NULL; 144 } 145 146 // Do manual alignment 147 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment); 148 149 // [ | | ] 150 // ^ extra_base 151 // ^ extra_base + begin_offset == aligned_base 152 // extra_base + begin_offset + size ^ 153 // extra_base + extra_size ^ 154 // |<>| == begin_offset 155 // end_offset == |<>| 156 size_t begin_offset = aligned_base - extra_base; 157 size_t end_offset = (extra_base + extra_size) - (aligned_base + size); 158 159 if (begin_offset > 0) { 160 os::release_memory(extra_base, begin_offset); 161 } 162 163 if (end_offset > 0) { 164 os::release_memory(extra_base + begin_offset + size, end_offset); 165 } 166 167 return aligned_base; 168 } 169 170 void os::Posix::print_load_average(outputStream* st) { 171 st->print("load average:"); 172 double loadavg[3]; 173 os::loadavg(loadavg, 3); 174 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]); 175 st->cr(); 176 } 177 178 void os::Posix::print_rlimit_info(outputStream* st) { 179 st->print("rlimit:"); 180 struct rlimit rlim; 181 182 st->print(" STACK "); 183 getrlimit(RLIMIT_STACK, &rlim); 184 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); 185 else st->print("%uk", rlim.rlim_cur >> 10); 186 187 st->print(", CORE "); 188 getrlimit(RLIMIT_CORE, &rlim); 189 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); 190 else st->print("%uk", rlim.rlim_cur >> 10); 191 192 // Isn't there on solaris 193 #if !defined(TARGET_OS_FAMILY_solaris) && !defined(TARGET_OS_FAMILY_aix) 194 st->print(", NPROC "); 195 getrlimit(RLIMIT_NPROC, &rlim); 196 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); 197 else st->print("%d", rlim.rlim_cur); 198 #endif 199 200 st->print(", NOFILE "); 201 getrlimit(RLIMIT_NOFILE, &rlim); 202 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); 203 else st->print("%d", rlim.rlim_cur); 204 205 st->print(", AS "); 206 getrlimit(RLIMIT_AS, &rlim); 207 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); 208 else st->print("%uk", rlim.rlim_cur >> 10); 209 st->cr(); 210 } 211 212 void os::Posix::print_uname_info(outputStream* st) { 213 // kernel 214 st->print("uname:"); 215 struct utsname name; 216 uname(&name); 217 st->print("%s ", name.sysname); 218 #ifdef ASSERT 219 st->print("%s ", name.nodename); 220 #endif 221 st->print("%s ", name.release); 222 st->print("%s ", name.version); 223 st->print("%s", name.machine); 224 st->cr(); 225 } 226 227 bool os::has_allocatable_memory_limit(julong* limit) { 228 struct rlimit rlim; 229 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim); 230 // if there was an error when calling getrlimit, assume that there is no limitation 231 // on virtual memory. 232 bool result; 233 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) { 234 result = false; 235 } else { 236 *limit = (julong)rlim.rlim_cur; 237 result = true; 238 } 239 #ifdef _LP64 240 return result; 241 #else 242 // arbitrary virtual space limit for 32 bit Unices found by testing. If 243 // getrlimit above returned a limit, bound it with this limit. Otherwise 244 // directly use it. 245 const julong max_virtual_limit = (julong)3800*M; 246 if (result) { 247 *limit = MIN2(*limit, max_virtual_limit); 248 } else { 249 *limit = max_virtual_limit; 250 } 251 252 // bound by actually allocatable memory. The algorithm uses two bounds, an 253 // upper and a lower limit. The upper limit is the current highest amount of 254 // memory that could not be allocated, the lower limit is the current highest 255 // amount of memory that could be allocated. 256 // The algorithm iteratively refines the result by halving the difference 257 // between these limits, updating either the upper limit (if that value could 258 // not be allocated) or the lower limit (if the that value could be allocated) 259 // until the difference between these limits is "small". 260 261 // the minimum amount of memory we care about allocating. 262 const julong min_allocation_size = M; 263 264 julong upper_limit = *limit; 265 266 // first check a few trivial cases 267 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) { 268 *limit = upper_limit; 269 } else if (!is_allocatable(min_allocation_size)) { 270 // we found that not even min_allocation_size is allocatable. Return it 271 // anyway. There is no point to search for a better value any more. 272 *limit = min_allocation_size; 273 } else { 274 // perform the binary search. 275 julong lower_limit = min_allocation_size; 276 while ((upper_limit - lower_limit) > min_allocation_size) { 277 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit; 278 temp_limit = align_size_down_(temp_limit, min_allocation_size); 279 if (is_allocatable(temp_limit)) { 280 lower_limit = temp_limit; 281 } else { 282 upper_limit = temp_limit; 283 } 284 } 285 *limit = lower_limit; 286 } 287 return true; 288 #endif 289 } 290 291 const char* os::get_current_directory(char *buf, size_t buflen) { 292 return getcwd(buf, buflen); 293 } 294 295 FILE* os::open(int fd, const char* mode) { 296 return ::fdopen(fd, mode); 297 } 298 299 // Builds a platform dependent Agent_OnLoad_<lib_name> function name 300 // which is used to find statically linked in agents. 301 // Parameters: 302 // sym_name: Symbol in library we are looking for 303 // lib_name: Name of library to look in, NULL for shared libs. 304 // is_absolute_path == true if lib_name is absolute path to agent 305 // such as "/a/b/libL.so" 306 // == false if only the base name of the library is passed in 307 // such as "L" 308 char* os::build_agent_function_name(const char *sym_name, const char *lib_name, 309 bool is_absolute_path) { 310 char *agent_entry_name; 311 size_t len; 312 size_t name_len; 313 size_t prefix_len = strlen(JNI_LIB_PREFIX); 314 size_t suffix_len = strlen(JNI_LIB_SUFFIX); 315 const char *start; 316 317 if (lib_name != NULL) { 318 len = name_len = strlen(lib_name); 319 if (is_absolute_path) { 320 // Need to strip path, prefix and suffix 321 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) { 322 lib_name = ++start; 323 } 324 if (len <= (prefix_len + suffix_len)) { 325 return NULL; 326 } 327 lib_name += prefix_len; 328 name_len = strlen(lib_name) - suffix_len; 329 } 330 } 331 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2; 332 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread); 333 if (agent_entry_name == NULL) { 334 return NULL; 335 } 336 strcpy(agent_entry_name, sym_name); 337 if (lib_name != NULL) { 338 strcat(agent_entry_name, "_"); 339 strncat(agent_entry_name, lib_name, name_len); 340 } 341 return agent_entry_name; 342 } 343 344 int os::sleep(Thread* thread, jlong millis, bool interruptible) { 345 assert(thread == Thread::current(), "thread consistency check"); 346 347 ParkEvent * const slp = thread->_SleepEvent ; 348 slp->reset() ; 349 OrderAccess::fence() ; 350 351 if (interruptible) { 352 jlong prevtime = javaTimeNanos(); 353 354 for (;;) { 355 if (os::is_interrupted(thread, true)) { 356 return OS_INTRPT; 357 } 358 359 jlong newtime = javaTimeNanos(); 360 361 if (newtime - prevtime < 0) { 362 // time moving backwards, should only happen if no monotonic clock 363 // not a guarantee() because JVM should not abort on kernel/glibc bugs 364 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)"); 365 } else { 366 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; 367 } 368 369 if (millis <= 0) { 370 return OS_OK; 371 } 372 373 prevtime = newtime; 374 375 { 376 assert(thread->is_Java_thread(), "sanity check"); 377 JavaThread *jt = (JavaThread *) thread; 378 ThreadBlockInVM tbivm(jt); 379 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */); 380 381 jt->set_suspend_equivalent(); 382 // cleared by handle_special_suspend_equivalent_condition() or 383 // java_suspend_self() via check_and_wait_while_suspended() 384 385 slp->park(millis); 386 387 // were we externally suspended while we were waiting? 388 jt->check_and_wait_while_suspended(); 389 } 390 } 391 } else { 392 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 393 jlong prevtime = javaTimeNanos(); 394 395 for (;;) { 396 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on 397 // the 1st iteration ... 398 jlong newtime = javaTimeNanos(); 399 400 if (newtime - prevtime < 0) { 401 // time moving backwards, should only happen if no monotonic clock 402 // not a guarantee() because JVM should not abort on kernel/glibc bugs 403 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)"); 404 } else { 405 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; 406 } 407 408 if (millis <= 0) break ; 409 410 prevtime = newtime; 411 slp->park(millis); 412 } 413 return OS_OK ; 414 } 415 } 416 417 //////////////////////////////////////////////////////////////////////////////// 418 // interrupt support 419 420 void os::interrupt(Thread* thread) { 421 assert(Thread::current() == thread || Threads_lock->owned_by_self(), 422 "possibility of dangling Thread pointer"); 423 424 OSThread* osthread = thread->osthread(); 425 426 if (!osthread->interrupted()) { 427 osthread->set_interrupted(true); 428 // More than one thread can get here with the same value of osthread, 429 // resulting in multiple notifications. We do, however, want the store 430 // to interrupted() to be visible to other threads before we execute unpark(). 431 OrderAccess::fence(); 432 ParkEvent * const slp = thread->_SleepEvent ; 433 if (slp != NULL) slp->unpark() ; 434 } 435 436 // For JSR166. Unpark even if interrupt status already was set 437 if (thread->is_Java_thread()) 438 ((JavaThread*)thread)->parker()->unpark(); 439 440 ParkEvent * ev = thread->_ParkEvent ; 441 if (ev != NULL) ev->unpark() ; 442 443 } 444 445 bool os::is_interrupted(Thread* thread, bool clear_interrupted) { 446 assert(Thread::current() == thread || Threads_lock->owned_by_self(), 447 "possibility of dangling Thread pointer"); 448 449 OSThread* osthread = thread->osthread(); 450 451 bool interrupted = osthread->interrupted(); 452 453 // NOTE that since there is no "lock" around the interrupt and 454 // is_interrupted operations, there is the possibility that the 455 // interrupted flag (in osThread) will be "false" but that the 456 // low-level events will be in the signaled state. This is 457 // intentional. The effect of this is that Object.wait() and 458 // LockSupport.park() will appear to have a spurious wakeup, which 459 // is allowed and not harmful, and the possibility is so rare that 460 // it is not worth the added complexity to add yet another lock. 461 // For the sleep event an explicit reset is performed on entry 462 // to os::sleep, so there is no early return. It has also been 463 // recommended not to put the interrupted flag into the "event" 464 // structure because it hides the issue. 465 if (interrupted && clear_interrupted) { 466 osthread->set_interrupted(false); 467 // consider thread->_SleepEvent->reset() ... optional optimization 468 } 469 470 return interrupted; 471 } 472 473 // Returned string is a constant. For unknown signals "UNKNOWN" is returned. 474 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) { 475 476 static const struct { 477 int sig; const char* name; 478 } 479 info[] = 480 { 481 { SIGABRT, "SIGABRT" }, 482 #ifdef SIGAIO 483 { SIGAIO, "SIGAIO" }, 484 #endif 485 { SIGALRM, "SIGALRM" }, 486 #ifdef SIGALRM1 487 { SIGALRM1, "SIGALRM1" }, 488 #endif 489 { SIGBUS, "SIGBUS" }, 490 #ifdef SIGCANCEL 491 { SIGCANCEL, "SIGCANCEL" }, 492 #endif 493 { SIGCHLD, "SIGCHLD" }, 494 #ifdef SIGCLD 495 { SIGCLD, "SIGCLD" }, 496 #endif 497 { SIGCONT, "SIGCONT" }, 498 #ifdef SIGCPUFAIL 499 { SIGCPUFAIL, "SIGCPUFAIL" }, 500 #endif 501 #ifdef SIGDANGER 502 { SIGDANGER, "SIGDANGER" }, 503 #endif 504 #ifdef SIGDIL 505 { SIGDIL, "SIGDIL" }, 506 #endif 507 #ifdef SIGEMT 508 { SIGEMT, "SIGEMT" }, 509 #endif 510 { SIGFPE, "SIGFPE" }, 511 #ifdef SIGFREEZE 512 { SIGFREEZE, "SIGFREEZE" }, 513 #endif 514 #ifdef SIGGFAULT 515 { SIGGFAULT, "SIGGFAULT" }, 516 #endif 517 #ifdef SIGGRANT 518 { SIGGRANT, "SIGGRANT" }, 519 #endif 520 { SIGHUP, "SIGHUP" }, 521 { SIGILL, "SIGILL" }, 522 { SIGINT, "SIGINT" }, 523 #ifdef SIGIO 524 { SIGIO, "SIGIO" }, 525 #endif 526 #ifdef SIGIOINT 527 { SIGIOINT, "SIGIOINT" }, 528 #endif 529 #ifdef SIGIOT 530 // SIGIOT is there for BSD compatibility, but on most Unices just a 531 // synonym for SIGABRT. The result should be "SIGABRT", not 532 // "SIGIOT". 533 #if (SIGIOT != SIGABRT ) 534 { SIGIOT, "SIGIOT" }, 535 #endif 536 #endif 537 #ifdef SIGKAP 538 { SIGKAP, "SIGKAP" }, 539 #endif 540 { SIGKILL, "SIGKILL" }, 541 #ifdef SIGLOST 542 { SIGLOST, "SIGLOST" }, 543 #endif 544 #ifdef SIGLWP 545 { SIGLWP, "SIGLWP" }, 546 #endif 547 #ifdef SIGLWPTIMER 548 { SIGLWPTIMER, "SIGLWPTIMER" }, 549 #endif 550 #ifdef SIGMIGRATE 551 { SIGMIGRATE, "SIGMIGRATE" }, 552 #endif 553 #ifdef SIGMSG 554 { SIGMSG, "SIGMSG" }, 555 #endif 556 { SIGPIPE, "SIGPIPE" }, 557 #ifdef SIGPOLL 558 { SIGPOLL, "SIGPOLL" }, 559 #endif 560 #ifdef SIGPRE 561 { SIGPRE, "SIGPRE" }, 562 #endif 563 { SIGPROF, "SIGPROF" }, 564 #ifdef SIGPTY 565 { SIGPTY, "SIGPTY" }, 566 #endif 567 #ifdef SIGPWR 568 { SIGPWR, "SIGPWR" }, 569 #endif 570 { SIGQUIT, "SIGQUIT" }, 571 #ifdef SIGRECONFIG 572 { SIGRECONFIG, "SIGRECONFIG" }, 573 #endif 574 #ifdef SIGRECOVERY 575 { SIGRECOVERY, "SIGRECOVERY" }, 576 #endif 577 #ifdef SIGRESERVE 578 { SIGRESERVE, "SIGRESERVE" }, 579 #endif 580 #ifdef SIGRETRACT 581 { SIGRETRACT, "SIGRETRACT" }, 582 #endif 583 #ifdef SIGSAK 584 { SIGSAK, "SIGSAK" }, 585 #endif 586 { SIGSEGV, "SIGSEGV" }, 587 #ifdef SIGSOUND 588 { SIGSOUND, "SIGSOUND" }, 589 #endif 590 { SIGSTOP, "SIGSTOP" }, 591 { SIGSYS, "SIGSYS" }, 592 #ifdef SIGSYSERROR 593 { SIGSYSERROR, "SIGSYSERROR" }, 594 #endif 595 #ifdef SIGTALRM 596 { SIGTALRM, "SIGTALRM" }, 597 #endif 598 { SIGTERM, "SIGTERM" }, 599 #ifdef SIGTHAW 600 { SIGTHAW, "SIGTHAW" }, 601 #endif 602 { SIGTRAP, "SIGTRAP" }, 603 #ifdef SIGTSTP 604 { SIGTSTP, "SIGTSTP" }, 605 #endif 606 { SIGTTIN, "SIGTTIN" }, 607 { SIGTTOU, "SIGTTOU" }, 608 #ifdef SIGURG 609 { SIGURG, "SIGURG" }, 610 #endif 611 { SIGUSR1, "SIGUSR1" }, 612 { SIGUSR2, "SIGUSR2" }, 613 #ifdef SIGVIRT 614 { SIGVIRT, "SIGVIRT" }, 615 #endif 616 { SIGVTALRM, "SIGVTALRM" }, 617 #ifdef SIGWAITING 618 { SIGWAITING, "SIGWAITING" }, 619 #endif 620 #ifdef SIGWINCH 621 { SIGWINCH, "SIGWINCH" }, 622 #endif 623 #ifdef SIGWINDOW 624 { SIGWINDOW, "SIGWINDOW" }, 625 #endif 626 { SIGXCPU, "SIGXCPU" }, 627 { SIGXFSZ, "SIGXFSZ" }, 628 #ifdef SIGXRES 629 { SIGXRES, "SIGXRES" }, 630 #endif 631 { -1, NULL } 632 }; 633 634 const char* ret = NULL; 635 636 #ifdef SIGRTMIN 637 if (sig >= SIGRTMIN && sig <= SIGRTMAX) { 638 if (sig == SIGRTMIN) { 639 ret = "SIGRTMIN"; 640 } else if (sig == SIGRTMAX) { 641 ret = "SIGRTMAX"; 642 } else { 643 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN); 644 return out; 645 } 646 } 647 #endif 648 649 if (sig > 0) { 650 for (int idx = 0; info[idx].sig != -1; idx ++) { 651 if (info[idx].sig == sig) { 652 ret = info[idx].name; 653 break; 654 } 655 } 656 } 657 658 if (!ret) { 659 if (!is_valid_signal(sig)) { 660 ret = "INVALID"; 661 } else { 662 ret = "UNKNOWN"; 663 } 664 } 665 666 if (out && outlen > 0) { 667 strncpy(out, ret, outlen); 668 out[outlen - 1] = '\0'; 669 } 670 return out; 671 } 672 673 // Returns true if signal number is valid. 674 bool os::Posix::is_valid_signal(int sig) { 675 // MacOS not really POSIX compliant: sigaddset does not return 676 // an error for invalid signal numbers. However, MacOS does not 677 // support real time signals and simply seems to have just 33 678 // signals with no holes in the signal range. 679 #ifdef __APPLE__ 680 return sig >= 1 && sig < NSIG; 681 #else 682 // Use sigaddset to check for signal validity. 683 sigset_t set; 684 if (sigaddset(&set, sig) == -1 && errno == EINVAL) { 685 return false; 686 } 687 return true; 688 #endif 689 } 690 691 #define NUM_IMPORTANT_SIGS 32 692 // Returns one-line short description of a signal set in a user provided buffer. 693 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) { 694 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size"); 695 // Note: for shortness, just print out the first 32. That should 696 // cover most of the useful ones, apart from realtime signals. 697 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) { 698 const int rc = sigismember(set, sig); 699 if (rc == -1 && errno == EINVAL) { 700 buffer[sig-1] = '?'; 701 } else { 702 buffer[sig-1] = rc == 0 ? '0' : '1'; 703 } 704 } 705 buffer[NUM_IMPORTANT_SIGS] = 0; 706 return buffer; 707 } 708 709 // Prints one-line description of a signal set. 710 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) { 711 char buf[NUM_IMPORTANT_SIGS + 1]; 712 os::Posix::describe_signal_set_short(set, buf, sizeof(buf)); 713 st->print("%s", buf); 714 } 715 716 // Writes one-line description of a combination of sigaction.sa_flags into a user 717 // provided buffer. Returns that buffer. 718 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) { 719 char* p = buffer; 720 size_t remaining = size; 721 bool first = true; 722 int idx = 0; 723 724 assert(buffer, "invalid argument"); 725 726 if (size == 0) { 727 return buffer; 728 } 729 730 strncpy(buffer, "none", size); 731 732 const struct { 733 int i; 734 const char* s; 735 } flaginfo [] = { 736 { SA_NOCLDSTOP, "SA_NOCLDSTOP" }, 737 { SA_ONSTACK, "SA_ONSTACK" }, 738 { SA_RESETHAND, "SA_RESETHAND" }, 739 { SA_RESTART, "SA_RESTART" }, 740 { SA_SIGINFO, "SA_SIGINFO" }, 741 { SA_NOCLDWAIT, "SA_NOCLDWAIT" }, 742 { SA_NODEFER, "SA_NODEFER" }, 743 #ifdef AIX 744 { SA_ONSTACK, "SA_ONSTACK" }, 745 { SA_OLDSTYLE, "SA_OLDSTYLE" }, 746 #endif 747 { 0, NULL } 748 }; 749 750 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) { 751 if (flags & flaginfo[idx].i) { 752 if (first) { 753 jio_snprintf(p, remaining, "%s", flaginfo[idx].s); 754 first = false; 755 } else { 756 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s); 757 } 758 const size_t len = strlen(p); 759 p += len; 760 remaining -= len; 761 } 762 } 763 764 buffer[size - 1] = '\0'; 765 766 return buffer; 767 } 768 769 // Prints one-line description of a combination of sigaction.sa_flags. 770 void os::Posix::print_sa_flags(outputStream* st, int flags) { 771 char buffer[0x100]; 772 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer)); 773 st->print("%s", buffer); 774 } 775 776 // Helper function for os::Posix::print_siginfo_...(): 777 // return a textual description for signal code. 778 struct enum_sigcode_desc_t { 779 const char* s_name; 780 const char* s_desc; 781 }; 782 783 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) { 784 785 const struct { 786 int sig; int code; const char* s_code; const char* s_desc; 787 } t1 [] = { 788 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." }, 789 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." }, 790 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." }, 791 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." }, 792 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." }, 793 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." }, 794 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." }, 795 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." }, 796 #if defined(IA64) && defined(LINUX) 797 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" }, 798 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" }, 799 #endif 800 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." }, 801 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." }, 802 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." }, 803 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." }, 804 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." }, 805 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." }, 806 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." }, 807 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." }, 808 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." }, 809 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." }, 810 #ifdef AIX 811 // no explanation found what keyerr would be 812 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" }, 813 #endif 814 #if defined(IA64) && !defined(AIX) 815 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" }, 816 #endif 817 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." }, 818 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." }, 819 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." }, 820 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." }, 821 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." }, 822 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." }, 823 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." }, 824 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." }, 825 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." }, 826 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." }, 827 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." }, 828 #ifdef SIGPOLL 829 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." }, 830 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." }, 831 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." }, 832 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." }, 833 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" }, 834 #endif 835 { -1, -1, NULL, NULL } 836 }; 837 838 // Codes valid in any signal context. 839 const struct { 840 int code; const char* s_code; const char* s_desc; 841 } t2 [] = { 842 { SI_USER, "SI_USER", "Signal sent by kill()." }, 843 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." }, 844 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." }, 845 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." }, 846 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." }, 847 // Linux specific 848 #ifdef SI_TKILL 849 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" }, 850 #endif 851 #ifdef SI_DETHREAD 852 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" }, 853 #endif 854 #ifdef SI_KERNEL 855 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." }, 856 #endif 857 #ifdef SI_SIGIO 858 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" }, 859 #endif 860 861 #ifdef AIX 862 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" }, 863 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" }, 864 #endif 865 866 #ifdef __sun 867 { SI_NOINFO, "SI_NOINFO", "No signal information" }, 868 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" }, 869 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" }, 870 #endif 871 872 { -1, NULL, NULL } 873 }; 874 875 const char* s_code = NULL; 876 const char* s_desc = NULL; 877 878 for (int i = 0; t1[i].sig != -1; i ++) { 879 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) { 880 s_code = t1[i].s_code; 881 s_desc = t1[i].s_desc; 882 break; 883 } 884 } 885 886 if (s_code == NULL) { 887 for (int i = 0; t2[i].s_code != NULL; i ++) { 888 if (t2[i].code == si->si_code) { 889 s_code = t2[i].s_code; 890 s_desc = t2[i].s_desc; 891 } 892 } 893 } 894 895 if (s_code == NULL) { 896 out->s_name = "unknown"; 897 out->s_desc = "unknown"; 898 return false; 899 } 900 901 out->s_name = s_code; 902 out->s_desc = s_desc; 903 904 return true; 905 } 906 907 // A POSIX conform, platform-independend siginfo print routine. 908 // Short print out on one line. 909 void os::Posix::print_siginfo_brief(outputStream* os, const siginfo_t* si) { 910 char buf[20]; 911 os->print("siginfo: "); 912 913 if (!si) { 914 os->print("<null>"); 915 return; 916 } 917 918 // See print_siginfo_full() for details. 919 const int sig = si->si_signo; 920 921 os->print("si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf))); 922 923 enum_sigcode_desc_t ed; 924 if (get_signal_code_description(si, &ed)) { 925 os->print(", si_code: %d (%s)", si->si_code, ed.s_name); 926 } else { 927 os->print(", si_code: %d (unknown)", si->si_code); 928 } 929 930 if (si->si_errno) { 931 os->print(", si_errno: %d", si->si_errno); 932 } 933 934 const int me = (int) ::getpid(); 935 const int pid = (int) si->si_pid; 936 937 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) { 938 if (IS_VALID_PID(pid) && pid != me) { 939 os->print(", sent from pid: %d (uid: %d)", pid, (int) si->si_uid); 940 } 941 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL || 942 sig == SIGTRAP || sig == SIGFPE) { 943 os->print(", si_addr: " PTR_FORMAT, si->si_addr); 944 #ifdef SIGPOLL 945 } else if (sig == SIGPOLL) { 946 os->print(", si_band: " PTR64_FORMAT, (uint64_t)si->si_band); 947 #endif 948 } else if (sig == SIGCHLD) { 949 os->print_cr(", si_pid: %d, si_uid: %d, si_status: %d", (int) si->si_pid, si->si_uid, si->si_status); 950 } 951 } 952 953 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() { 954 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread"); 955 } 956 957 /* 958 * See the caveats for this class in os_posix.hpp 959 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this 960 * method and returns false. If none of the signals are raised, returns true. 961 * The callback is supposed to provide the method that should be protected. 962 */ 963 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) { 964 sigset_t saved_sig_mask; 965 966 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread"); 967 assert(!WatcherThread::watcher_thread()->has_crash_protection(), 968 "crash_protection already set?"); 969 970 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask 971 // since on at least some systems (OS X) siglongjmp will restore the mask 972 // for the process, not the thread 973 pthread_sigmask(0, NULL, &saved_sig_mask); 974 if (sigsetjmp(_jmpbuf, 0) == 0) { 975 // make sure we can see in the signal handler that we have crash protection 976 // installed 977 WatcherThread::watcher_thread()->set_crash_protection(this); 978 cb.call(); 979 // and clear the crash protection 980 WatcherThread::watcher_thread()->set_crash_protection(NULL); 981 return true; 982 } 983 // this happens when we siglongjmp() back 984 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL); 985 WatcherThread::watcher_thread()->set_crash_protection(NULL); 986 return false; 987 } 988 989 void os::WatcherThreadCrashProtection::restore() { 990 assert(WatcherThread::watcher_thread()->has_crash_protection(), 991 "must have crash protection"); 992 993 siglongjmp(_jmpbuf, 1); 994 } 995 996 void os::WatcherThreadCrashProtection::check_crash_protection(int sig, 997 Thread* thread) { 998 999 if (thread != NULL && 1000 thread->is_Watcher_thread() && 1001 WatcherThread::watcher_thread()->has_crash_protection()) { 1002 1003 if (sig == SIGSEGV || sig == SIGBUS) { 1004 WatcherThread::watcher_thread()->crash_protection()->restore(); 1005 } 1006 } 1007 }