1 /* 2 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // no precompiled headers 26 #include "jvm.h" 27 #include "classfile/classLoader.hpp" 28 #include "classfile/systemDictionary.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "code/icBuffer.hpp" 31 #include "code/vtableStubs.hpp" 32 #include "compiler/compileBroker.hpp" 33 #include "compiler/disassembler.hpp" 34 #include "interpreter/interpreter.hpp" 35 #include "logging/log.hpp" 36 #include "memory/allocation.inline.hpp" 37 #include "memory/filemap.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "os_linux.inline.hpp" 40 #include "os_share_linux.hpp" 41 #include "osContainer_linux.hpp" 42 #include "prims/jniFastGetField.hpp" 43 #include "prims/jvm_misc.hpp" 44 #include "runtime/arguments.hpp" 45 #include "runtime/atomic.hpp" 46 #include "runtime/extendedPC.hpp" 47 #include "runtime/globals.hpp" 48 #include "runtime/interfaceSupport.inline.hpp" 49 #include "runtime/init.hpp" 50 #include "runtime/java.hpp" 51 #include "runtime/javaCalls.hpp" 52 #include "runtime/mutexLocker.hpp" 53 #include "runtime/objectMonitor.hpp" 54 #include "runtime/orderAccess.inline.hpp" 55 #include "runtime/osThread.hpp" 56 #include "runtime/perfMemory.hpp" 57 #include "runtime/sharedRuntime.hpp" 58 #include "runtime/statSampler.hpp" 59 #include "runtime/stubRoutines.hpp" 60 #include "runtime/thread.inline.hpp" 61 #include "runtime/threadCritical.hpp" 62 #include "runtime/threadSMR.hpp" 63 #include "runtime/timer.hpp" 64 #include "semaphore_posix.hpp" 65 #include "services/attachListener.hpp" 66 #include "services/memTracker.hpp" 67 #include "services/runtimeService.hpp" 68 #include "utilities/align.hpp" 69 #include "utilities/decoder.hpp" 70 #include "utilities/defaultStream.hpp" 71 #include "utilities/events.hpp" 72 #include "utilities/elfFile.hpp" 73 #include "utilities/growableArray.hpp" 74 #include "utilities/macros.hpp" 75 #include "utilities/vmError.hpp" 76 77 // put OS-includes here 78 # include <sys/types.h> 79 # include <sys/mman.h> 80 # include <sys/stat.h> 81 # include <sys/select.h> 82 # include <pthread.h> 83 # include <signal.h> 84 # include <errno.h> 85 # include <dlfcn.h> 86 # include <stdio.h> 87 # include <unistd.h> 88 # include <sys/resource.h> 89 # include <pthread.h> 90 # include <sys/stat.h> 91 # include <sys/time.h> 92 # include <sys/times.h> 93 # include <sys/utsname.h> 94 # include <sys/socket.h> 95 # include <sys/wait.h> 96 # include <pwd.h> 97 # include <poll.h> 98 # include <fcntl.h> 99 # include <string.h> 100 # include <syscall.h> 101 # include <sys/sysinfo.h> 102 # include <gnu/libc-version.h> 103 # include <sys/ipc.h> 104 # include <sys/shm.h> 105 # include <link.h> 106 # include <stdint.h> 107 # include <inttypes.h> 108 # include <sys/ioctl.h> 109 110 #ifndef _GNU_SOURCE 111 #define _GNU_SOURCE 112 #include <sched.h> 113 #undef _GNU_SOURCE 114 #else 115 #include <sched.h> 116 #endif 117 118 // if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling 119 // getrusage() is prepared to handle the associated failure. 120 #ifndef RUSAGE_THREAD 121 #define RUSAGE_THREAD (1) /* only the calling thread */ 122 #endif 123 124 #define MAX_PATH (2 * K) 125 126 #define MAX_SECS 100000000 127 128 // for timer info max values which include all bits 129 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 130 131 #define LARGEPAGES_BIT (1 << 6) 132 #define DAX_SHARED_BIT (1 << 8) 133 //////////////////////////////////////////////////////////////////////////////// 134 // global variables 135 julong os::Linux::_physical_memory = 0; 136 137 address os::Linux::_initial_thread_stack_bottom = NULL; 138 uintptr_t os::Linux::_initial_thread_stack_size = 0; 139 140 int (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL; 141 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL; 142 int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL; 143 Mutex* os::Linux::_createThread_lock = NULL; 144 pthread_t os::Linux::_main_thread; 145 int os::Linux::_page_size = -1; 146 bool os::Linux::_supports_fast_thread_cpu_time = false; 147 uint32_t os::Linux::_os_version = 0; 148 const char * os::Linux::_glibc_version = NULL; 149 const char * os::Linux::_libpthread_version = NULL; 150 151 static jlong initial_time_count=0; 152 153 static int clock_tics_per_sec = 100; 154 155 // For diagnostics to print a message once. see run_periodic_checks 156 static sigset_t check_signal_done; 157 static bool check_signals = true; 158 159 // Signal number used to suspend/resume a thread 160 161 // do not use any signal number less than SIGSEGV, see 4355769 162 static int SR_signum = SIGUSR2; 163 sigset_t SR_sigset; 164 165 // utility functions 166 167 static int SR_initialize(); 168 169 julong os::available_memory() { 170 return Linux::available_memory(); 171 } 172 173 julong os::Linux::available_memory() { 174 // values in struct sysinfo are "unsigned long" 175 struct sysinfo si; 176 julong avail_mem; 177 178 if (OSContainer::is_containerized()) { 179 jlong mem_limit, mem_usage; 180 if ((mem_limit = OSContainer::memory_limit_in_bytes()) < 1) { 181 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value", 182 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit); 183 } 184 if (mem_limit > 0 && (mem_usage = OSContainer::memory_usage_in_bytes()) < 1) { 185 log_debug(os, container)("container memory usage failed: " JLONG_FORMAT ", using host value", mem_usage); 186 } 187 if (mem_limit > 0 && mem_usage > 0 ) { 188 avail_mem = mem_limit > mem_usage ? (julong)mem_limit - (julong)mem_usage : 0; 189 log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem); 190 return avail_mem; 191 } 192 } 193 194 sysinfo(&si); 195 avail_mem = (julong)si.freeram * si.mem_unit; 196 log_trace(os)("available memory: " JULONG_FORMAT, avail_mem); 197 return avail_mem; 198 } 199 200 julong os::physical_memory() { 201 jlong phys_mem = 0; 202 if (OSContainer::is_containerized()) { 203 jlong mem_limit; 204 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) { 205 log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit); 206 return mem_limit; 207 } 208 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value", 209 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit); 210 } 211 212 phys_mem = Linux::physical_memory(); 213 log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem); 214 return phys_mem; 215 } 216 217 // Return true if user is running as root. 218 219 bool os::have_special_privileges() { 220 static bool init = false; 221 static bool privileges = false; 222 if (!init) { 223 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 224 init = true; 225 } 226 return privileges; 227 } 228 229 230 #ifndef SYS_gettid 231 // i386: 224, ia64: 1105, amd64: 186, sparc 143 232 #ifdef __ia64__ 233 #define SYS_gettid 1105 234 #else 235 #ifdef __i386__ 236 #define SYS_gettid 224 237 #else 238 #ifdef __amd64__ 239 #define SYS_gettid 186 240 #else 241 #ifdef __sparc__ 242 #define SYS_gettid 143 243 #else 244 #error define gettid for the arch 245 #endif 246 #endif 247 #endif 248 #endif 249 #endif 250 251 252 // pid_t gettid() 253 // 254 // Returns the kernel thread id of the currently running thread. Kernel 255 // thread id is used to access /proc. 256 pid_t os::Linux::gettid() { 257 int rslt = syscall(SYS_gettid); 258 assert(rslt != -1, "must be."); // old linuxthreads implementation? 259 return (pid_t)rslt; 260 } 261 262 // Most versions of linux have a bug where the number of processors are 263 // determined by looking at the /proc file system. In a chroot environment, 264 // the system call returns 1. This causes the VM to act as if it is 265 // a single processor and elide locking (see is_MP() call). 266 static bool unsafe_chroot_detected = false; 267 static const char *unstable_chroot_error = "/proc file system not found.\n" 268 "Java may be unstable running multithreaded in a chroot " 269 "environment on Linux when /proc filesystem is not mounted."; 270 271 void os::Linux::initialize_system_info() { 272 set_processor_count(sysconf(_SC_NPROCESSORS_CONF)); 273 if (processor_count() == 1) { 274 pid_t pid = os::Linux::gettid(); 275 char fname[32]; 276 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid); 277 FILE *fp = fopen(fname, "r"); 278 if (fp == NULL) { 279 unsafe_chroot_detected = true; 280 } else { 281 fclose(fp); 282 } 283 } 284 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE); 285 assert(processor_count() > 0, "linux error"); 286 } 287 288 void os::init_system_properties_values() { 289 // The next steps are taken in the product version: 290 // 291 // Obtain the JAVA_HOME value from the location of libjvm.so. 292 // This library should be located at: 293 // <JAVA_HOME>/lib/{client|server}/libjvm.so. 294 // 295 // If "/jre/lib/" appears at the right place in the path, then we 296 // assume libjvm.so is installed in a JDK and we use this path. 297 // 298 // Otherwise exit with message: "Could not create the Java virtual machine." 299 // 300 // The following extra steps are taken in the debugging version: 301 // 302 // If "/jre/lib/" does NOT appear at the right place in the path 303 // instead of exit check for $JAVA_HOME environment variable. 304 // 305 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 306 // then we append a fake suffix "hotspot/libjvm.so" to this path so 307 // it looks like libjvm.so is installed there 308 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 309 // 310 // Otherwise exit. 311 // 312 // Important note: if the location of libjvm.so changes this 313 // code needs to be changed accordingly. 314 315 // See ld(1): 316 // The linker uses the following search paths to locate required 317 // shared libraries: 318 // 1: ... 319 // ... 320 // 7: The default directories, normally /lib and /usr/lib. 321 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390) 322 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib" 323 #else 324 #define DEFAULT_LIBPATH "/lib:/usr/lib" 325 #endif 326 327 // Base path of extensions installed on the system. 328 #define SYS_EXT_DIR "/usr/java/packages" 329 #define EXTENSIONS_DIR "/lib/ext" 330 331 // Buffer that fits several sprintfs. 332 // Note that the space for the colon and the trailing null are provided 333 // by the nulls included by the sizeof operator. 334 const size_t bufsize = 335 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 336 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 337 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 338 339 // sysclasspath, java_home, dll_dir 340 { 341 char *pslash; 342 os::jvm_path(buf, bufsize); 343 344 // Found the full path to libjvm.so. 345 // Now cut the path to <java_home>/jre if we can. 346 pslash = strrchr(buf, '/'); 347 if (pslash != NULL) { 348 *pslash = '\0'; // Get rid of /libjvm.so. 349 } 350 pslash = strrchr(buf, '/'); 351 if (pslash != NULL) { 352 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 353 } 354 Arguments::set_dll_dir(buf); 355 356 if (pslash != NULL) { 357 pslash = strrchr(buf, '/'); 358 if (pslash != NULL) { 359 *pslash = '\0'; // Get rid of /lib. 360 } 361 } 362 Arguments::set_java_home(buf); 363 set_boot_path('/', ':'); 364 } 365 366 // Where to look for native libraries. 367 // 368 // Note: Due to a legacy implementation, most of the library path 369 // is set in the launcher. This was to accomodate linking restrictions 370 // on legacy Linux implementations (which are no longer supported). 371 // Eventually, all the library path setting will be done here. 372 // 373 // However, to prevent the proliferation of improperly built native 374 // libraries, the new path component /usr/java/packages is added here. 375 // Eventually, all the library path setting will be done here. 376 { 377 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 378 // should always exist (until the legacy problem cited above is 379 // addressed). 380 const char *v = ::getenv("LD_LIBRARY_PATH"); 381 const char *v_colon = ":"; 382 if (v == NULL) { v = ""; v_colon = ""; } 383 // That's +1 for the colon and +1 for the trailing '\0'. 384 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 385 strlen(v) + 1 + 386 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1, 387 mtInternal); 388 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon); 389 Arguments::set_library_path(ld_library_path); 390 FREE_C_HEAP_ARRAY(char, ld_library_path); 391 } 392 393 // Extensions directories. 394 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 395 Arguments::set_ext_dirs(buf); 396 397 FREE_C_HEAP_ARRAY(char, buf); 398 399 #undef DEFAULT_LIBPATH 400 #undef SYS_EXT_DIR 401 #undef EXTENSIONS_DIR 402 } 403 404 //////////////////////////////////////////////////////////////////////////////// 405 // breakpoint support 406 407 void os::breakpoint() { 408 BREAKPOINT; 409 } 410 411 extern "C" void breakpoint() { 412 // use debugger to set breakpoint here 413 } 414 415 //////////////////////////////////////////////////////////////////////////////// 416 // signal support 417 418 debug_only(static bool signal_sets_initialized = false); 419 static sigset_t unblocked_sigs, vm_sigs; 420 421 bool os::Linux::is_sig_ignored(int sig) { 422 struct sigaction oact; 423 sigaction(sig, (struct sigaction*)NULL, &oact); 424 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 425 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 426 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 427 return true; 428 } else { 429 return false; 430 } 431 } 432 433 void os::Linux::signal_sets_init() { 434 // Should also have an assertion stating we are still single-threaded. 435 assert(!signal_sets_initialized, "Already initialized"); 436 // Fill in signals that are necessarily unblocked for all threads in 437 // the VM. Currently, we unblock the following signals: 438 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 439 // by -Xrs (=ReduceSignalUsage)); 440 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 441 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 442 // the dispositions or masks wrt these signals. 443 // Programs embedding the VM that want to use the above signals for their 444 // own purposes must, at this time, use the "-Xrs" option to prevent 445 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 446 // (See bug 4345157, and other related bugs). 447 // In reality, though, unblocking these signals is really a nop, since 448 // these signals are not blocked by default. 449 sigemptyset(&unblocked_sigs); 450 sigaddset(&unblocked_sigs, SIGILL); 451 sigaddset(&unblocked_sigs, SIGSEGV); 452 sigaddset(&unblocked_sigs, SIGBUS); 453 sigaddset(&unblocked_sigs, SIGFPE); 454 #if defined(PPC64) 455 sigaddset(&unblocked_sigs, SIGTRAP); 456 #endif 457 sigaddset(&unblocked_sigs, SR_signum); 458 459 if (!ReduceSignalUsage) { 460 if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 461 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 462 } 463 if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 464 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 465 } 466 if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 467 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 468 } 469 } 470 // Fill in signals that are blocked by all but the VM thread. 471 sigemptyset(&vm_sigs); 472 if (!ReduceSignalUsage) { 473 sigaddset(&vm_sigs, BREAK_SIGNAL); 474 } 475 debug_only(signal_sets_initialized = true); 476 477 } 478 479 // These are signals that are unblocked while a thread is running Java. 480 // (For some reason, they get blocked by default.) 481 sigset_t* os::Linux::unblocked_signals() { 482 assert(signal_sets_initialized, "Not initialized"); 483 return &unblocked_sigs; 484 } 485 486 // These are the signals that are blocked while a (non-VM) thread is 487 // running Java. Only the VM thread handles these signals. 488 sigset_t* os::Linux::vm_signals() { 489 assert(signal_sets_initialized, "Not initialized"); 490 return &vm_sigs; 491 } 492 493 void os::Linux::hotspot_sigmask(Thread* thread) { 494 495 //Save caller's signal mask before setting VM signal mask 496 sigset_t caller_sigmask; 497 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 498 499 OSThread* osthread = thread->osthread(); 500 osthread->set_caller_sigmask(caller_sigmask); 501 502 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL); 503 504 if (!ReduceSignalUsage) { 505 if (thread->is_VM_thread()) { 506 // Only the VM thread handles BREAK_SIGNAL ... 507 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 508 } else { 509 // ... all other threads block BREAK_SIGNAL 510 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 511 } 512 } 513 } 514 515 ////////////////////////////////////////////////////////////////////////////// 516 // detecting pthread library 517 518 void os::Linux::libpthread_init() { 519 // Save glibc and pthread version strings. 520 #if !defined(_CS_GNU_LIBC_VERSION) || \ 521 !defined(_CS_GNU_LIBPTHREAD_VERSION) 522 #error "glibc too old (< 2.3.2)" 523 #endif 524 525 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); 526 assert(n > 0, "cannot retrieve glibc version"); 527 char *str = (char *)malloc(n, mtInternal); 528 confstr(_CS_GNU_LIBC_VERSION, str, n); 529 os::Linux::set_glibc_version(str); 530 531 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); 532 assert(n > 0, "cannot retrieve pthread version"); 533 str = (char *)malloc(n, mtInternal); 534 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); 535 os::Linux::set_libpthread_version(str); 536 } 537 538 ///////////////////////////////////////////////////////////////////////////// 539 // thread stack expansion 540 541 // os::Linux::manually_expand_stack() takes care of expanding the thread 542 // stack. Note that this is normally not needed: pthread stacks allocate 543 // thread stack using mmap() without MAP_NORESERVE, so the stack is already 544 // committed. Therefore it is not necessary to expand the stack manually. 545 // 546 // Manually expanding the stack was historically needed on LinuxThreads 547 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays 548 // it is kept to deal with very rare corner cases: 549 // 550 // For one, user may run the VM on an own implementation of threads 551 // whose stacks are - like the old LinuxThreads - implemented using 552 // mmap(MAP_GROWSDOWN). 553 // 554 // Also, this coding may be needed if the VM is running on the primordial 555 // thread. Normally we avoid running on the primordial thread; however, 556 // user may still invoke the VM on the primordial thread. 557 // 558 // The following historical comment describes the details about running 559 // on a thread stack allocated with mmap(MAP_GROWSDOWN): 560 561 562 // Force Linux kernel to expand current thread stack. If "bottom" is close 563 // to the stack guard, caller should block all signals. 564 // 565 // MAP_GROWSDOWN: 566 // A special mmap() flag that is used to implement thread stacks. It tells 567 // kernel that the memory region should extend downwards when needed. This 568 // allows early versions of LinuxThreads to only mmap the first few pages 569 // when creating a new thread. Linux kernel will automatically expand thread 570 // stack as needed (on page faults). 571 // 572 // However, because the memory region of a MAP_GROWSDOWN stack can grow on 573 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN 574 // region, it's hard to tell if the fault is due to a legitimate stack 575 // access or because of reading/writing non-exist memory (e.g. buffer 576 // overrun). As a rule, if the fault happens below current stack pointer, 577 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the 578 // application (see Linux kernel fault.c). 579 // 580 // This Linux feature can cause SIGSEGV when VM bangs thread stack for 581 // stack overflow detection. 582 // 583 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do 584 // not use MAP_GROWSDOWN. 585 // 586 // To get around the problem and allow stack banging on Linux, we need to 587 // manually expand thread stack after receiving the SIGSEGV. 588 // 589 // There are two ways to expand thread stack to address "bottom", we used 590 // both of them in JVM before 1.5: 591 // 1. adjust stack pointer first so that it is below "bottom", and then 592 // touch "bottom" 593 // 2. mmap() the page in question 594 // 595 // Now alternate signal stack is gone, it's harder to use 2. For instance, 596 // if current sp is already near the lower end of page 101, and we need to 597 // call mmap() to map page 100, it is possible that part of the mmap() frame 598 // will be placed in page 100. When page 100 is mapped, it is zero-filled. 599 // That will destroy the mmap() frame and cause VM to crash. 600 // 601 // The following code works by adjusting sp first, then accessing the "bottom" 602 // page to force a page fault. Linux kernel will then automatically expand the 603 // stack mapping. 604 // 605 // _expand_stack_to() assumes its frame size is less than page size, which 606 // should always be true if the function is not inlined. 607 608 static void NOINLINE _expand_stack_to(address bottom) { 609 address sp; 610 size_t size; 611 volatile char *p; 612 613 // Adjust bottom to point to the largest address within the same page, it 614 // gives us a one-page buffer if alloca() allocates slightly more memory. 615 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size()); 616 bottom += os::Linux::page_size() - 1; 617 618 // sp might be slightly above current stack pointer; if that's the case, we 619 // will alloca() a little more space than necessary, which is OK. Don't use 620 // os::current_stack_pointer(), as its result can be slightly below current 621 // stack pointer, causing us to not alloca enough to reach "bottom". 622 sp = (address)&sp; 623 624 if (sp > bottom) { 625 size = sp - bottom; 626 p = (volatile char *)alloca(size); 627 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); 628 p[0] = '\0'; 629 } 630 } 631 632 void os::Linux::expand_stack_to(address bottom) { 633 _expand_stack_to(bottom); 634 } 635 636 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) { 637 assert(t!=NULL, "just checking"); 638 assert(t->osthread()->expanding_stack(), "expand should be set"); 639 assert(t->stack_base() != NULL, "stack_base was not initialized"); 640 641 if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) { 642 sigset_t mask_all, old_sigset; 643 sigfillset(&mask_all); 644 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); 645 _expand_stack_to(addr); 646 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); 647 return true; 648 } 649 return false; 650 } 651 652 ////////////////////////////////////////////////////////////////////////////// 653 // create new thread 654 655 // Thread start routine for all newly created threads 656 static void *thread_native_entry(Thread *thread) { 657 // Try to randomize the cache line index of hot stack frames. 658 // This helps when threads of the same stack traces evict each other's 659 // cache lines. The threads can be either from the same JVM instance, or 660 // from different JVM instances. The benefit is especially true for 661 // processors with hyperthreading technology. 662 static int counter = 0; 663 int pid = os::current_process_id(); 664 alloca(((pid ^ counter++) & 7) * 128); 665 666 thread->initialize_thread_current(); 667 668 OSThread* osthread = thread->osthread(); 669 Monitor* sync = osthread->startThread_lock(); 670 671 osthread->set_thread_id(os::current_thread_id()); 672 673 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 674 os::current_thread_id(), (uintx) pthread_self()); 675 676 if (UseNUMA) { 677 int lgrp_id = os::numa_get_group_id(); 678 if (lgrp_id != -1) { 679 thread->set_lgrp_id(lgrp_id); 680 } 681 } 682 // initialize signal mask for this thread 683 os::Linux::hotspot_sigmask(thread); 684 685 // initialize floating point control register 686 os::Linux::init_thread_fpu_state(); 687 688 // handshaking with parent thread 689 { 690 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 691 692 // notify parent thread 693 osthread->set_state(INITIALIZED); 694 sync->notify_all(); 695 696 // wait until os::start_thread() 697 while (osthread->get_state() == INITIALIZED) { 698 sync->wait(Mutex::_no_safepoint_check_flag); 699 } 700 } 701 702 // call one more level start routine 703 thread->run(); 704 705 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 706 os::current_thread_id(), (uintx) pthread_self()); 707 708 // If a thread has not deleted itself ("delete this") as part of its 709 // termination sequence, we have to ensure thread-local-storage is 710 // cleared before we actually terminate. No threads should ever be 711 // deleted asynchronously with respect to their termination. 712 if (Thread::current_or_null_safe() != NULL) { 713 assert(Thread::current_or_null_safe() == thread, "current thread is wrong"); 714 thread->clear_thread_current(); 715 } 716 717 return 0; 718 } 719 720 bool os::create_thread(Thread* thread, ThreadType thr_type, 721 size_t req_stack_size) { 722 assert(thread->osthread() == NULL, "caller responsible"); 723 724 // Allocate the OSThread object 725 OSThread* osthread = new OSThread(NULL, NULL); 726 if (osthread == NULL) { 727 return false; 728 } 729 730 // set the correct thread state 731 osthread->set_thread_type(thr_type); 732 733 // Initial state is ALLOCATED but not INITIALIZED 734 osthread->set_state(ALLOCATED); 735 736 thread->set_osthread(osthread); 737 738 // init thread attributes 739 pthread_attr_t attr; 740 pthread_attr_init(&attr); 741 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 742 743 // Calculate stack size if it's not specified by caller. 744 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size); 745 // In the Linux NPTL pthread implementation the guard size mechanism 746 // is not implemented properly. The posix standard requires adding 747 // the size of the guard pages to the stack size, instead Linux 748 // takes the space out of 'stacksize'. Thus we adapt the requested 749 // stack_size by the size of the guard pages to mimick proper 750 // behaviour. However, be careful not to end up with a size 751 // of zero due to overflow. Don't add the guard page in that case. 752 size_t guard_size = os::Linux::default_guard_size(thr_type); 753 if (stack_size <= SIZE_MAX - guard_size) { 754 stack_size += guard_size; 755 } 756 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned"); 757 758 int status = pthread_attr_setstacksize(&attr, stack_size); 759 assert_status(status == 0, status, "pthread_attr_setstacksize"); 760 761 // Configure glibc guard page. 762 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); 763 764 ThreadState state; 765 766 { 767 pthread_t tid; 768 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread); 769 770 char buf[64]; 771 if (ret == 0) { 772 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ", 773 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 774 } else { 775 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.", 776 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 777 } 778 779 pthread_attr_destroy(&attr); 780 781 if (ret != 0) { 782 // Need to clean up stuff we've allocated so far 783 thread->set_osthread(NULL); 784 delete osthread; 785 return false; 786 } 787 788 // Store pthread info into the OSThread 789 osthread->set_pthread_id(tid); 790 791 // Wait until child thread is either initialized or aborted 792 { 793 Monitor* sync_with_child = osthread->startThread_lock(); 794 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 795 while ((state = osthread->get_state()) == ALLOCATED) { 796 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 797 } 798 } 799 } 800 801 // Aborted due to thread limit being reached 802 if (state == ZOMBIE) { 803 thread->set_osthread(NULL); 804 delete osthread; 805 return false; 806 } 807 808 // The thread is returned suspended (in state INITIALIZED), 809 // and is started higher up in the call chain 810 assert(state == INITIALIZED, "race condition"); 811 return true; 812 } 813 814 ///////////////////////////////////////////////////////////////////////////// 815 // attach existing thread 816 817 // bootstrap the main thread 818 bool os::create_main_thread(JavaThread* thread) { 819 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread"); 820 return create_attached_thread(thread); 821 } 822 823 bool os::create_attached_thread(JavaThread* thread) { 824 #ifdef ASSERT 825 thread->verify_not_published(); 826 #endif 827 828 // Allocate the OSThread object 829 OSThread* osthread = new OSThread(NULL, NULL); 830 831 if (osthread == NULL) { 832 return false; 833 } 834 835 // Store pthread info into the OSThread 836 osthread->set_thread_id(os::Linux::gettid()); 837 osthread->set_pthread_id(::pthread_self()); 838 839 // initialize floating point control register 840 os::Linux::init_thread_fpu_state(); 841 842 // Initial thread state is RUNNABLE 843 osthread->set_state(RUNNABLE); 844 845 thread->set_osthread(osthread); 846 847 if (UseNUMA) { 848 int lgrp_id = os::numa_get_group_id(); 849 if (lgrp_id != -1) { 850 thread->set_lgrp_id(lgrp_id); 851 } 852 } 853 854 if (os::is_primordial_thread()) { 855 // If current thread is primordial thread, its stack is mapped on demand, 856 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map 857 // the entire stack region to avoid SEGV in stack banging. 858 // It is also useful to get around the heap-stack-gap problem on SuSE 859 // kernel (see 4821821 for details). We first expand stack to the top 860 // of yellow zone, then enable stack yellow zone (order is significant, 861 // enabling yellow zone first will crash JVM on SuSE Linux), so there 862 // is no gap between the last two virtual memory regions. 863 864 JavaThread *jt = (JavaThread *)thread; 865 address addr = jt->stack_reserved_zone_base(); 866 assert(addr != NULL, "initialization problem?"); 867 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); 868 869 osthread->set_expanding_stack(); 870 os::Linux::manually_expand_stack(jt, addr); 871 osthread->clear_expanding_stack(); 872 } 873 874 // initialize signal mask for this thread 875 // and save the caller's signal mask 876 os::Linux::hotspot_sigmask(thread); 877 878 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 879 os::current_thread_id(), (uintx) pthread_self()); 880 881 return true; 882 } 883 884 void os::pd_start_thread(Thread* thread) { 885 OSThread * osthread = thread->osthread(); 886 assert(osthread->get_state() != INITIALIZED, "just checking"); 887 Monitor* sync_with_child = osthread->startThread_lock(); 888 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 889 sync_with_child->notify(); 890 } 891 892 // Free Linux resources related to the OSThread 893 void os::free_thread(OSThread* osthread) { 894 assert(osthread != NULL, "osthread not set"); 895 896 // We are told to free resources of the argument thread, 897 // but we can only really operate on the current thread. 898 assert(Thread::current()->osthread() == osthread, 899 "os::free_thread but not current thread"); 900 901 #ifdef ASSERT 902 sigset_t current; 903 sigemptyset(¤t); 904 pthread_sigmask(SIG_SETMASK, NULL, ¤t); 905 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!"); 906 #endif 907 908 // Restore caller's signal mask 909 sigset_t sigmask = osthread->caller_sigmask(); 910 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 911 912 delete osthread; 913 } 914 915 ////////////////////////////////////////////////////////////////////////////// 916 // primordial thread 917 918 // Check if current thread is the primordial thread, similar to Solaris thr_main. 919 bool os::is_primordial_thread(void) { 920 char dummy; 921 // If called before init complete, thread stack bottom will be null. 922 // Can be called if fatal error occurs before initialization. 923 if (os::Linux::initial_thread_stack_bottom() == NULL) return false; 924 assert(os::Linux::initial_thread_stack_bottom() != NULL && 925 os::Linux::initial_thread_stack_size() != 0, 926 "os::init did not locate primordial thread's stack region"); 927 if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() && 928 (address)&dummy < os::Linux::initial_thread_stack_bottom() + 929 os::Linux::initial_thread_stack_size()) { 930 return true; 931 } else { 932 return false; 933 } 934 } 935 936 // Find the virtual memory area that contains addr 937 static bool find_vma(address addr, address* vma_low, address* vma_high) { 938 FILE *fp = fopen("/proc/self/maps", "r"); 939 if (fp) { 940 address low, high; 941 while (!feof(fp)) { 942 if (fscanf(fp, "%p-%p", &low, &high) == 2) { 943 if (low <= addr && addr < high) { 944 if (vma_low) *vma_low = low; 945 if (vma_high) *vma_high = high; 946 fclose(fp); 947 return true; 948 } 949 } 950 for (;;) { 951 int ch = fgetc(fp); 952 if (ch == EOF || ch == (int)'\n') break; 953 } 954 } 955 fclose(fp); 956 } 957 return false; 958 } 959 960 // Locate primordial thread stack. This special handling of primordial thread stack 961 // is needed because pthread_getattr_np() on most (all?) Linux distros returns 962 // bogus value for the primordial process thread. While the launcher has created 963 // the VM in a new thread since JDK 6, we still have to allow for the use of the 964 // JNI invocation API from a primordial thread. 965 void os::Linux::capture_initial_stack(size_t max_size) { 966 967 // max_size is either 0 (which means accept OS default for thread stacks) or 968 // a user-specified value known to be at least the minimum needed. If we 969 // are actually on the primordial thread we can make it appear that we have a 970 // smaller max_size stack by inserting the guard pages at that location. But we 971 // cannot do anything to emulate a larger stack than what has been provided by 972 // the OS or threading library. In fact if we try to use a stack greater than 973 // what is set by rlimit then we will crash the hosting process. 974 975 // Maximum stack size is the easy part, get it from RLIMIT_STACK. 976 // If this is "unlimited" then it will be a huge value. 977 struct rlimit rlim; 978 getrlimit(RLIMIT_STACK, &rlim); 979 size_t stack_size = rlim.rlim_cur; 980 981 // 6308388: a bug in ld.so will relocate its own .data section to the 982 // lower end of primordial stack; reduce ulimit -s value a little bit 983 // so we won't install guard page on ld.so's data section. 984 // But ensure we don't underflow the stack size - allow 1 page spare 985 if (stack_size >= (size_t)(3 * page_size())) { 986 stack_size -= 2 * page_size(); 987 } 988 989 // Try to figure out where the stack base (top) is. This is harder. 990 // 991 // When an application is started, glibc saves the initial stack pointer in 992 // a global variable "__libc_stack_end", which is then used by system 993 // libraries. __libc_stack_end should be pretty close to stack top. The 994 // variable is available since the very early days. However, because it is 995 // a private interface, it could disappear in the future. 996 // 997 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar 998 // to __libc_stack_end, it is very close to stack top, but isn't the real 999 // stack top. Note that /proc may not exist if VM is running as a chroot 1000 // program, so reading /proc/<pid>/stat could fail. Also the contents of 1001 // /proc/<pid>/stat could change in the future (though unlikely). 1002 // 1003 // We try __libc_stack_end first. If that doesn't work, look for 1004 // /proc/<pid>/stat. If neither of them works, we use current stack pointer 1005 // as a hint, which should work well in most cases. 1006 1007 uintptr_t stack_start; 1008 1009 // try __libc_stack_end first 1010 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end"); 1011 if (p && *p) { 1012 stack_start = *p; 1013 } else { 1014 // see if we can get the start_stack field from /proc/self/stat 1015 FILE *fp; 1016 int pid; 1017 char state; 1018 int ppid; 1019 int pgrp; 1020 int session; 1021 int nr; 1022 int tpgrp; 1023 unsigned long flags; 1024 unsigned long minflt; 1025 unsigned long cminflt; 1026 unsigned long majflt; 1027 unsigned long cmajflt; 1028 unsigned long utime; 1029 unsigned long stime; 1030 long cutime; 1031 long cstime; 1032 long prio; 1033 long nice; 1034 long junk; 1035 long it_real; 1036 uintptr_t start; 1037 uintptr_t vsize; 1038 intptr_t rss; 1039 uintptr_t rsslim; 1040 uintptr_t scodes; 1041 uintptr_t ecode; 1042 int i; 1043 1044 // Figure what the primordial thread stack base is. Code is inspired 1045 // by email from Hans Boehm. /proc/self/stat begins with current pid, 1046 // followed by command name surrounded by parentheses, state, etc. 1047 char stat[2048]; 1048 int statlen; 1049 1050 fp = fopen("/proc/self/stat", "r"); 1051 if (fp) { 1052 statlen = fread(stat, 1, 2047, fp); 1053 stat[statlen] = '\0'; 1054 fclose(fp); 1055 1056 // Skip pid and the command string. Note that we could be dealing with 1057 // weird command names, e.g. user could decide to rename java launcher 1058 // to "java 1.4.2 :)", then the stat file would look like 1059 // 1234 (java 1.4.2 :)) R ... ... 1060 // We don't really need to know the command string, just find the last 1061 // occurrence of ")" and then start parsing from there. See bug 4726580. 1062 char * s = strrchr(stat, ')'); 1063 1064 i = 0; 1065 if (s) { 1066 // Skip blank chars 1067 do { s++; } while (s && isspace(*s)); 1068 1069 #define _UFM UINTX_FORMAT 1070 #define _DFM INTX_FORMAT 1071 1072 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 1073 // 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 1074 i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM, 1075 &state, // 3 %c 1076 &ppid, // 4 %d 1077 &pgrp, // 5 %d 1078 &session, // 6 %d 1079 &nr, // 7 %d 1080 &tpgrp, // 8 %d 1081 &flags, // 9 %lu 1082 &minflt, // 10 %lu 1083 &cminflt, // 11 %lu 1084 &majflt, // 12 %lu 1085 &cmajflt, // 13 %lu 1086 &utime, // 14 %lu 1087 &stime, // 15 %lu 1088 &cutime, // 16 %ld 1089 &cstime, // 17 %ld 1090 &prio, // 18 %ld 1091 &nice, // 19 %ld 1092 &junk, // 20 %ld 1093 &it_real, // 21 %ld 1094 &start, // 22 UINTX_FORMAT 1095 &vsize, // 23 UINTX_FORMAT 1096 &rss, // 24 INTX_FORMAT 1097 &rsslim, // 25 UINTX_FORMAT 1098 &scodes, // 26 UINTX_FORMAT 1099 &ecode, // 27 UINTX_FORMAT 1100 &stack_start); // 28 UINTX_FORMAT 1101 } 1102 1103 #undef _UFM 1104 #undef _DFM 1105 1106 if (i != 28 - 2) { 1107 assert(false, "Bad conversion from /proc/self/stat"); 1108 // product mode - assume we are the primordial thread, good luck in the 1109 // embedded case. 1110 warning("Can't detect primordial thread stack location - bad conversion"); 1111 stack_start = (uintptr_t) &rlim; 1112 } 1113 } else { 1114 // For some reason we can't open /proc/self/stat (for example, running on 1115 // FreeBSD with a Linux emulator, or inside chroot), this should work for 1116 // most cases, so don't abort: 1117 warning("Can't detect primordial thread stack location - no /proc/self/stat"); 1118 stack_start = (uintptr_t) &rlim; 1119 } 1120 } 1121 1122 // Now we have a pointer (stack_start) very close to the stack top, the 1123 // next thing to do is to figure out the exact location of stack top. We 1124 // can find out the virtual memory area that contains stack_start by 1125 // reading /proc/self/maps, it should be the last vma in /proc/self/maps, 1126 // and its upper limit is the real stack top. (again, this would fail if 1127 // running inside chroot, because /proc may not exist.) 1128 1129 uintptr_t stack_top; 1130 address low, high; 1131 if (find_vma((address)stack_start, &low, &high)) { 1132 // success, "high" is the true stack top. (ignore "low", because initial 1133 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.) 1134 stack_top = (uintptr_t)high; 1135 } else { 1136 // failed, likely because /proc/self/maps does not exist 1137 warning("Can't detect primordial thread stack location - find_vma failed"); 1138 // best effort: stack_start is normally within a few pages below the real 1139 // stack top, use it as stack top, and reduce stack size so we won't put 1140 // guard page outside stack. 1141 stack_top = stack_start; 1142 stack_size -= 16 * page_size(); 1143 } 1144 1145 // stack_top could be partially down the page so align it 1146 stack_top = align_up(stack_top, page_size()); 1147 1148 // Allowed stack value is minimum of max_size and what we derived from rlimit 1149 if (max_size > 0) { 1150 _initial_thread_stack_size = MIN2(max_size, stack_size); 1151 } else { 1152 // Accept the rlimit max, but if stack is unlimited then it will be huge, so 1153 // clamp it at 8MB as we do on Solaris 1154 _initial_thread_stack_size = MIN2(stack_size, 8*M); 1155 } 1156 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size()); 1157 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; 1158 1159 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!"); 1160 1161 if (log_is_enabled(Info, os, thread)) { 1162 // See if we seem to be on primordial process thread 1163 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) && 1164 uintptr_t(&rlim) < stack_top; 1165 1166 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: " 1167 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT, 1168 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K, 1169 stack_top, intptr_t(_initial_thread_stack_bottom)); 1170 } 1171 } 1172 1173 //////////////////////////////////////////////////////////////////////////////// 1174 // time support 1175 1176 // Time since start-up in seconds to a fine granularity. 1177 // Used by VMSelfDestructTimer and the MemProfiler. 1178 double os::elapsedTime() { 1179 1180 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution 1181 } 1182 1183 jlong os::elapsed_counter() { 1184 return javaTimeNanos() - initial_time_count; 1185 } 1186 1187 jlong os::elapsed_frequency() { 1188 return NANOSECS_PER_SEC; // nanosecond resolution 1189 } 1190 1191 bool os::supports_vtime() { return true; } 1192 bool os::enable_vtime() { return false; } 1193 bool os::vtime_enabled() { return false; } 1194 1195 double os::elapsedVTime() { 1196 struct rusage usage; 1197 int retval = getrusage(RUSAGE_THREAD, &usage); 1198 if (retval == 0) { 1199 return (double) (usage.ru_utime.tv_sec + usage.ru_stime.tv_sec) + (double) (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000 * 1000); 1200 } else { 1201 // better than nothing, but not much 1202 return elapsedTime(); 1203 } 1204 } 1205 1206 jlong os::javaTimeMillis() { 1207 timeval time; 1208 int status = gettimeofday(&time, NULL); 1209 assert(status != -1, "linux error"); 1210 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 1211 } 1212 1213 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { 1214 timeval time; 1215 int status = gettimeofday(&time, NULL); 1216 assert(status != -1, "linux error"); 1217 seconds = jlong(time.tv_sec); 1218 nanos = jlong(time.tv_usec) * 1000; 1219 } 1220 1221 1222 #ifndef CLOCK_MONOTONIC 1223 #define CLOCK_MONOTONIC (1) 1224 #endif 1225 1226 void os::Linux::clock_init() { 1227 // we do dlopen's in this particular order due to bug in linux 1228 // dynamical loader (see 6348968) leading to crash on exit 1229 void* handle = dlopen("librt.so.1", RTLD_LAZY); 1230 if (handle == NULL) { 1231 handle = dlopen("librt.so", RTLD_LAZY); 1232 } 1233 1234 if (handle) { 1235 int (*clock_getres_func)(clockid_t, struct timespec*) = 1236 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres"); 1237 int (*clock_gettime_func)(clockid_t, struct timespec*) = 1238 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime"); 1239 if (clock_getres_func && clock_gettime_func) { 1240 // See if monotonic clock is supported by the kernel. Note that some 1241 // early implementations simply return kernel jiffies (updated every 1242 // 1/100 or 1/1000 second). It would be bad to use such a low res clock 1243 // for nano time (though the monotonic property is still nice to have). 1244 // It's fixed in newer kernels, however clock_getres() still returns 1245 // 1/HZ. We check if clock_getres() works, but will ignore its reported 1246 // resolution for now. Hopefully as people move to new kernels, this 1247 // won't be a problem. 1248 struct timespec res; 1249 struct timespec tp; 1250 if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 && 1251 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) { 1252 // yes, monotonic clock is supported 1253 _clock_gettime = clock_gettime_func; 1254 return; 1255 } else { 1256 // close librt if there is no monotonic clock 1257 dlclose(handle); 1258 } 1259 } 1260 } 1261 warning("No monotonic clock was available - timed services may " \ 1262 "be adversely affected if the time-of-day clock changes"); 1263 } 1264 1265 #ifndef SYS_clock_getres 1266 #if defined(X86) || defined(PPC64) || defined(S390) 1267 #define SYS_clock_getres AMD64_ONLY(229) IA32_ONLY(266) PPC64_ONLY(247) S390_ONLY(261) 1268 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1269 #else 1270 #warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time" 1271 #define sys_clock_getres(x,y) -1 1272 #endif 1273 #else 1274 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1275 #endif 1276 1277 void os::Linux::fast_thread_clock_init() { 1278 if (!UseLinuxPosixThreadCPUClocks) { 1279 return; 1280 } 1281 clockid_t clockid; 1282 struct timespec tp; 1283 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) = 1284 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid"); 1285 1286 // Switch to using fast clocks for thread cpu time if 1287 // the sys_clock_getres() returns 0 error code. 1288 // Note, that some kernels may support the current thread 1289 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks 1290 // returned by the pthread_getcpuclockid(). 1291 // If the fast Posix clocks are supported then the sys_clock_getres() 1292 // must return at least tp.tv_sec == 0 which means a resolution 1293 // better than 1 sec. This is extra check for reliability. 1294 1295 if (pthread_getcpuclockid_func && 1296 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 && 1297 sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) { 1298 _supports_fast_thread_cpu_time = true; 1299 _pthread_getcpuclockid = pthread_getcpuclockid_func; 1300 } 1301 } 1302 1303 jlong os::javaTimeNanos() { 1304 if (os::supports_monotonic_clock()) { 1305 struct timespec tp; 1306 int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp); 1307 assert(status == 0, "gettime error"); 1308 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1309 return result; 1310 } else { 1311 timeval time; 1312 int status = gettimeofday(&time, NULL); 1313 assert(status != -1, "linux error"); 1314 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1315 return 1000 * usecs; 1316 } 1317 } 1318 1319 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1320 if (os::supports_monotonic_clock()) { 1321 info_ptr->max_value = ALL_64_BITS; 1322 1323 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1324 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1325 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1326 } else { 1327 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1328 info_ptr->max_value = ALL_64_BITS; 1329 1330 // gettimeofday is a real time clock so it skips 1331 info_ptr->may_skip_backward = true; 1332 info_ptr->may_skip_forward = true; 1333 } 1334 1335 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1336 } 1337 1338 // Return the real, user, and system times in seconds from an 1339 // arbitrary fixed point in the past. 1340 bool os::getTimesSecs(double* process_real_time, 1341 double* process_user_time, 1342 double* process_system_time) { 1343 struct tms ticks; 1344 clock_t real_ticks = times(&ticks); 1345 1346 if (real_ticks == (clock_t) (-1)) { 1347 return false; 1348 } else { 1349 double ticks_per_second = (double) clock_tics_per_sec; 1350 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1351 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1352 *process_real_time = ((double) real_ticks) / ticks_per_second; 1353 1354 return true; 1355 } 1356 } 1357 1358 1359 char * os::local_time_string(char *buf, size_t buflen) { 1360 struct tm t; 1361 time_t long_time; 1362 time(&long_time); 1363 localtime_r(&long_time, &t); 1364 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1365 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1366 t.tm_hour, t.tm_min, t.tm_sec); 1367 return buf; 1368 } 1369 1370 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1371 return localtime_r(clock, res); 1372 } 1373 1374 //////////////////////////////////////////////////////////////////////////////// 1375 // runtime exit support 1376 1377 // Note: os::shutdown() might be called very early during initialization, or 1378 // called from signal handler. Before adding something to os::shutdown(), make 1379 // sure it is async-safe and can handle partially initialized VM. 1380 void os::shutdown() { 1381 1382 // allow PerfMemory to attempt cleanup of any persistent resources 1383 perfMemory_exit(); 1384 1385 // needs to remove object in file system 1386 AttachListener::abort(); 1387 1388 // flush buffered output, finish log files 1389 ostream_abort(); 1390 1391 // Check for abort hook 1392 abort_hook_t abort_hook = Arguments::abort_hook(); 1393 if (abort_hook != NULL) { 1394 abort_hook(); 1395 } 1396 1397 } 1398 1399 // Note: os::abort() might be called very early during initialization, or 1400 // called from signal handler. Before adding something to os::abort(), make 1401 // sure it is async-safe and can handle partially initialized VM. 1402 void os::abort(bool dump_core, void* siginfo, const void* context) { 1403 os::shutdown(); 1404 if (dump_core) { 1405 #ifndef PRODUCT 1406 fdStream out(defaultStream::output_fd()); 1407 out.print_raw("Current thread is "); 1408 char buf[16]; 1409 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1410 out.print_raw_cr(buf); 1411 out.print_raw_cr("Dumping core ..."); 1412 #endif 1413 ::abort(); // dump core 1414 } 1415 1416 ::exit(1); 1417 } 1418 1419 // Die immediately, no exit hook, no abort hook, no cleanup. 1420 void os::die() { 1421 ::abort(); 1422 } 1423 1424 1425 // This method is a copy of JDK's sysGetLastErrorString 1426 // from src/solaris/hpi/src/system_md.c 1427 1428 size_t os::lasterror(char *buf, size_t len) { 1429 if (errno == 0) return 0; 1430 1431 const char *s = os::strerror(errno); 1432 size_t n = ::strlen(s); 1433 if (n >= len) { 1434 n = len - 1; 1435 } 1436 ::strncpy(buf, s, n); 1437 buf[n] = '\0'; 1438 return n; 1439 } 1440 1441 // thread_id is kernel thread id (similar to Solaris LWP id) 1442 intx os::current_thread_id() { return os::Linux::gettid(); } 1443 int os::current_process_id() { 1444 return ::getpid(); 1445 } 1446 1447 // DLL functions 1448 1449 const char* os::dll_file_extension() { return ".so"; } 1450 1451 // This must be hard coded because it's the system's temporary 1452 // directory not the java application's temp directory, ala java.io.tmpdir. 1453 const char* os::get_temp_directory() { return "/tmp"; } 1454 1455 static bool file_exists(const char* filename) { 1456 struct stat statbuf; 1457 if (filename == NULL || strlen(filename) == 0) { 1458 return false; 1459 } 1460 return os::stat(filename, &statbuf) == 0; 1461 } 1462 1463 // check if addr is inside libjvm.so 1464 bool os::address_is_in_vm(address addr) { 1465 static address libjvm_base_addr; 1466 Dl_info dlinfo; 1467 1468 if (libjvm_base_addr == NULL) { 1469 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1470 libjvm_base_addr = (address)dlinfo.dli_fbase; 1471 } 1472 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1473 } 1474 1475 if (dladdr((void *)addr, &dlinfo) != 0) { 1476 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1477 } 1478 1479 return false; 1480 } 1481 1482 bool os::dll_address_to_function_name(address addr, char *buf, 1483 int buflen, int *offset, 1484 bool demangle) { 1485 // buf is not optional, but offset is optional 1486 assert(buf != NULL, "sanity check"); 1487 1488 Dl_info dlinfo; 1489 1490 if (dladdr((void*)addr, &dlinfo) != 0) { 1491 // see if we have a matching symbol 1492 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1493 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) { 1494 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1495 } 1496 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1497 return true; 1498 } 1499 // no matching symbol so try for just file info 1500 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1501 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1502 buf, buflen, offset, dlinfo.dli_fname, demangle)) { 1503 return true; 1504 } 1505 } 1506 } 1507 1508 buf[0] = '\0'; 1509 if (offset != NULL) *offset = -1; 1510 return false; 1511 } 1512 1513 struct _address_to_library_name { 1514 address addr; // input : memory address 1515 size_t buflen; // size of fname 1516 char* fname; // output: library name 1517 address base; // library base addr 1518 }; 1519 1520 static int address_to_library_name_callback(struct dl_phdr_info *info, 1521 size_t size, void *data) { 1522 int i; 1523 bool found = false; 1524 address libbase = NULL; 1525 struct _address_to_library_name * d = (struct _address_to_library_name *)data; 1526 1527 // iterate through all loadable segments 1528 for (i = 0; i < info->dlpi_phnum; i++) { 1529 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); 1530 if (info->dlpi_phdr[i].p_type == PT_LOAD) { 1531 // base address of a library is the lowest address of its loaded 1532 // segments. 1533 if (libbase == NULL || libbase > segbase) { 1534 libbase = segbase; 1535 } 1536 // see if 'addr' is within current segment 1537 if (segbase <= d->addr && 1538 d->addr < segbase + info->dlpi_phdr[i].p_memsz) { 1539 found = true; 1540 } 1541 } 1542 } 1543 1544 // dlpi_name is NULL or empty if the ELF file is executable, return 0 1545 // so dll_address_to_library_name() can fall through to use dladdr() which 1546 // can figure out executable name from argv[0]. 1547 if (found && info->dlpi_name && info->dlpi_name[0]) { 1548 d->base = libbase; 1549 if (d->fname) { 1550 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); 1551 } 1552 return 1; 1553 } 1554 return 0; 1555 } 1556 1557 bool os::dll_address_to_library_name(address addr, char* buf, 1558 int buflen, int* offset) { 1559 // buf is not optional, but offset is optional 1560 assert(buf != NULL, "sanity check"); 1561 1562 Dl_info dlinfo; 1563 struct _address_to_library_name data; 1564 1565 // There is a bug in old glibc dladdr() implementation that it could resolve 1566 // to wrong library name if the .so file has a base address != NULL. Here 1567 // we iterate through the program headers of all loaded libraries to find 1568 // out which library 'addr' really belongs to. This workaround can be 1569 // removed once the minimum requirement for glibc is moved to 2.3.x. 1570 data.addr = addr; 1571 data.fname = buf; 1572 data.buflen = buflen; 1573 data.base = NULL; 1574 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); 1575 1576 if (rslt) { 1577 // buf already contains library name 1578 if (offset) *offset = addr - data.base; 1579 return true; 1580 } 1581 if (dladdr((void*)addr, &dlinfo) != 0) { 1582 if (dlinfo.dli_fname != NULL) { 1583 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1584 } 1585 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1586 *offset = addr - (address)dlinfo.dli_fbase; 1587 } 1588 return true; 1589 } 1590 1591 buf[0] = '\0'; 1592 if (offset) *offset = -1; 1593 return false; 1594 } 1595 1596 // Loads .dll/.so and 1597 // in case of error it checks if .dll/.so was built for the 1598 // same architecture as Hotspot is running on 1599 1600 1601 // Remember the stack's state. The Linux dynamic linker will change 1602 // the stack to 'executable' at most once, so we must safepoint only once. 1603 bool os::Linux::_stack_is_executable = false; 1604 1605 // VM operation that loads a library. This is necessary if stack protection 1606 // of the Java stacks can be lost during loading the library. If we 1607 // do not stop the Java threads, they can stack overflow before the stacks 1608 // are protected again. 1609 class VM_LinuxDllLoad: public VM_Operation { 1610 private: 1611 const char *_filename; 1612 char *_ebuf; 1613 int _ebuflen; 1614 void *_lib; 1615 public: 1616 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) : 1617 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {} 1618 VMOp_Type type() const { return VMOp_LinuxDllLoad; } 1619 void doit() { 1620 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen); 1621 os::Linux::_stack_is_executable = true; 1622 } 1623 void* loaded_library() { return _lib; } 1624 }; 1625 1626 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1627 void * result = NULL; 1628 bool load_attempted = false; 1629 1630 // Check whether the library to load might change execution rights 1631 // of the stack. If they are changed, the protection of the stack 1632 // guard pages will be lost. We need a safepoint to fix this. 1633 // 1634 // See Linux man page execstack(8) for more info. 1635 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) { 1636 if (!ElfFile::specifies_noexecstack(filename)) { 1637 if (!is_init_completed()) { 1638 os::Linux::_stack_is_executable = true; 1639 // This is OK - No Java threads have been created yet, and hence no 1640 // stack guard pages to fix. 1641 // 1642 // This should happen only when you are building JDK7 using a very 1643 // old version of JDK6 (e.g., with JPRT) and running test_gamma. 1644 // 1645 // Dynamic loader will make all stacks executable after 1646 // this function returns, and will not do that again. 1647 assert(Threads::number_of_threads() == 0, "no Java threads should exist yet."); 1648 } else { 1649 warning("You have loaded library %s which might have disabled stack guard. " 1650 "The VM will try to fix the stack guard now.\n" 1651 "It's highly recommended that you fix the library with " 1652 "'execstack -c <libfile>', or link it with '-z noexecstack'.", 1653 filename); 1654 1655 assert(Thread::current()->is_Java_thread(), "must be Java thread"); 1656 JavaThread *jt = JavaThread::current(); 1657 if (jt->thread_state() != _thread_in_native) { 1658 // This happens when a compiler thread tries to load a hsdis-<arch>.so file 1659 // that requires ExecStack. Cannot enter safe point. Let's give up. 1660 warning("Unable to fix stack guard. Giving up."); 1661 } else { 1662 if (!LoadExecStackDllInVMThread) { 1663 // This is for the case where the DLL has an static 1664 // constructor function that executes JNI code. We cannot 1665 // load such DLLs in the VMThread. 1666 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1667 } 1668 1669 ThreadInVMfromNative tiv(jt); 1670 debug_only(VMNativeEntryWrapper vew;) 1671 1672 VM_LinuxDllLoad op(filename, ebuf, ebuflen); 1673 VMThread::execute(&op); 1674 if (LoadExecStackDllInVMThread) { 1675 result = op.loaded_library(); 1676 } 1677 load_attempted = true; 1678 } 1679 } 1680 } 1681 } 1682 1683 if (!load_attempted) { 1684 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1685 } 1686 1687 if (result != NULL) { 1688 // Successful loading 1689 return result; 1690 } 1691 1692 Elf32_Ehdr elf_head; 1693 int diag_msg_max_length=ebuflen-strlen(ebuf); 1694 char* diag_msg_buf=ebuf+strlen(ebuf); 1695 1696 if (diag_msg_max_length==0) { 1697 // No more space in ebuf for additional diagnostics message 1698 return NULL; 1699 } 1700 1701 1702 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1703 1704 if (file_descriptor < 0) { 1705 // Can't open library, report dlerror() message 1706 return NULL; 1707 } 1708 1709 bool failed_to_read_elf_head= 1710 (sizeof(elf_head)!= 1711 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1712 1713 ::close(file_descriptor); 1714 if (failed_to_read_elf_head) { 1715 // file i/o error - report dlerror() msg 1716 return NULL; 1717 } 1718 1719 typedef struct { 1720 Elf32_Half code; // Actual value as defined in elf.h 1721 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1722 unsigned char elf_class; // 32 or 64 bit 1723 unsigned char endianess; // MSB or LSB 1724 char* name; // String representation 1725 } arch_t; 1726 1727 #ifndef EM_486 1728 #define EM_486 6 /* Intel 80486 */ 1729 #endif 1730 #ifndef EM_AARCH64 1731 #define EM_AARCH64 183 /* ARM AARCH64 */ 1732 #endif 1733 1734 static const arch_t arch_array[]={ 1735 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1736 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1737 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1738 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1739 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1740 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1741 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1742 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1743 #if defined(VM_LITTLE_ENDIAN) 1744 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"}, 1745 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"}, 1746 #else 1747 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1748 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"}, 1749 #endif 1750 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1751 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1752 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1753 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1754 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1755 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1756 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}, 1757 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"}, 1758 }; 1759 1760 #if (defined IA32) 1761 static Elf32_Half running_arch_code=EM_386; 1762 #elif (defined AMD64) 1763 static Elf32_Half running_arch_code=EM_X86_64; 1764 #elif (defined IA64) 1765 static Elf32_Half running_arch_code=EM_IA_64; 1766 #elif (defined __sparc) && (defined _LP64) 1767 static Elf32_Half running_arch_code=EM_SPARCV9; 1768 #elif (defined __sparc) && (!defined _LP64) 1769 static Elf32_Half running_arch_code=EM_SPARC; 1770 #elif (defined __powerpc64__) 1771 static Elf32_Half running_arch_code=EM_PPC64; 1772 #elif (defined __powerpc__) 1773 static Elf32_Half running_arch_code=EM_PPC; 1774 #elif (defined AARCH64) 1775 static Elf32_Half running_arch_code=EM_AARCH64; 1776 #elif (defined ARM) 1777 static Elf32_Half running_arch_code=EM_ARM; 1778 #elif (defined S390) 1779 static Elf32_Half running_arch_code=EM_S390; 1780 #elif (defined ALPHA) 1781 static Elf32_Half running_arch_code=EM_ALPHA; 1782 #elif (defined MIPSEL) 1783 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1784 #elif (defined PARISC) 1785 static Elf32_Half running_arch_code=EM_PARISC; 1786 #elif (defined MIPS) 1787 static Elf32_Half running_arch_code=EM_MIPS; 1788 #elif (defined M68K) 1789 static Elf32_Half running_arch_code=EM_68K; 1790 #elif (defined SH) 1791 static Elf32_Half running_arch_code=EM_SH; 1792 #else 1793 #error Method os::dll_load requires that one of following is defined:\ 1794 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc 1795 #endif 1796 1797 // Identify compatability class for VM's architecture and library's architecture 1798 // Obtain string descriptions for architectures 1799 1800 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1801 int running_arch_index=-1; 1802 1803 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1804 if (running_arch_code == arch_array[i].code) { 1805 running_arch_index = i; 1806 } 1807 if (lib_arch.code == arch_array[i].code) { 1808 lib_arch.compat_class = arch_array[i].compat_class; 1809 lib_arch.name = arch_array[i].name; 1810 } 1811 } 1812 1813 assert(running_arch_index != -1, 1814 "Didn't find running architecture code (running_arch_code) in arch_array"); 1815 if (running_arch_index == -1) { 1816 // Even though running architecture detection failed 1817 // we may still continue with reporting dlerror() message 1818 return NULL; 1819 } 1820 1821 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1822 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1823 return NULL; 1824 } 1825 1826 #ifndef S390 1827 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1828 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1829 return NULL; 1830 } 1831 #endif // !S390 1832 1833 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1834 if (lib_arch.name!=NULL) { 1835 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1836 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1837 lib_arch.name, arch_array[running_arch_index].name); 1838 } else { 1839 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1840 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1841 lib_arch.code, 1842 arch_array[running_arch_index].name); 1843 } 1844 } 1845 1846 return NULL; 1847 } 1848 1849 void * os::Linux::dlopen_helper(const char *filename, char *ebuf, 1850 int ebuflen) { 1851 void * result = ::dlopen(filename, RTLD_LAZY); 1852 if (result == NULL) { 1853 ::strncpy(ebuf, ::dlerror(), ebuflen - 1); 1854 ebuf[ebuflen-1] = '\0'; 1855 } 1856 return result; 1857 } 1858 1859 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf, 1860 int ebuflen) { 1861 void * result = NULL; 1862 if (LoadExecStackDllInVMThread) { 1863 result = dlopen_helper(filename, ebuf, ebuflen); 1864 } 1865 1866 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a 1867 // library that requires an executable stack, or which does not have this 1868 // stack attribute set, dlopen changes the stack attribute to executable. The 1869 // read protection of the guard pages gets lost. 1870 // 1871 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad 1872 // may have been queued at the same time. 1873 1874 if (!_stack_is_executable) { 1875 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) { 1876 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized 1877 jt->stack_guards_enabled()) { // No pending stack overflow exceptions 1878 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) { 1879 warning("Attempt to reguard stack yellow zone failed."); 1880 } 1881 } 1882 } 1883 } 1884 1885 return result; 1886 } 1887 1888 void* os::dll_lookup(void* handle, const char* name) { 1889 void* res = dlsym(handle, name); 1890 return res; 1891 } 1892 1893 void* os::get_default_process_handle() { 1894 return (void*)::dlopen(NULL, RTLD_LAZY); 1895 } 1896 1897 static bool _print_ascii_file(const char* filename, outputStream* st) { 1898 int fd = ::open(filename, O_RDONLY); 1899 if (fd == -1) { 1900 return false; 1901 } 1902 1903 char buf[33]; 1904 int bytes; 1905 buf[32] = '\0'; 1906 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) { 1907 st->print_raw(buf, bytes); 1908 } 1909 1910 ::close(fd); 1911 1912 return true; 1913 } 1914 1915 void os::print_dll_info(outputStream *st) { 1916 st->print_cr("Dynamic libraries:"); 1917 1918 char fname[32]; 1919 pid_t pid = os::Linux::gettid(); 1920 1921 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); 1922 1923 if (!_print_ascii_file(fname, st)) { 1924 st->print("Can not get library information for pid = %d\n", pid); 1925 } 1926 } 1927 1928 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1929 FILE *procmapsFile = NULL; 1930 1931 // Open the procfs maps file for the current process 1932 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) { 1933 // Allocate PATH_MAX for file name plus a reasonable size for other fields. 1934 char line[PATH_MAX + 100]; 1935 1936 // Read line by line from 'file' 1937 while (fgets(line, sizeof(line), procmapsFile) != NULL) { 1938 u8 base, top, offset, inode; 1939 char permissions[5]; 1940 char device[6]; 1941 char name[PATH_MAX + 1]; 1942 1943 // Parse fields from line 1944 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s", 1945 &base, &top, permissions, &offset, device, &inode, name); 1946 1947 // Filter by device id '00:00' so that we only get file system mapped files. 1948 if (strcmp(device, "00:00") != 0) { 1949 1950 // Call callback with the fields of interest 1951 if(callback(name, (address)base, (address)top, param)) { 1952 // Oops abort, callback aborted 1953 fclose(procmapsFile); 1954 return 1; 1955 } 1956 } 1957 } 1958 fclose(procmapsFile); 1959 } 1960 return 0; 1961 } 1962 1963 void os::print_os_info_brief(outputStream* st) { 1964 os::Linux::print_distro_info(st); 1965 1966 os::Posix::print_uname_info(st); 1967 1968 os::Linux::print_libversion_info(st); 1969 1970 } 1971 1972 void os::print_os_info(outputStream* st) { 1973 st->print("OS:"); 1974 1975 os::Linux::print_distro_info(st); 1976 1977 os::Posix::print_uname_info(st); 1978 1979 // Print warning if unsafe chroot environment detected 1980 if (unsafe_chroot_detected) { 1981 st->print("WARNING!! "); 1982 st->print_cr("%s", unstable_chroot_error); 1983 } 1984 1985 os::Linux::print_libversion_info(st); 1986 1987 os::Posix::print_rlimit_info(st); 1988 1989 os::Posix::print_load_average(st); 1990 1991 os::Linux::print_full_memory_info(st); 1992 1993 os::Linux::print_container_info(st); 1994 } 1995 1996 // Try to identify popular distros. 1997 // Most Linux distributions have a /etc/XXX-release file, which contains 1998 // the OS version string. Newer Linux distributions have a /etc/lsb-release 1999 // file that also contains the OS version string. Some have more than one 2000 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and 2001 // /etc/redhat-release.), so the order is important. 2002 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have 2003 // their own specific XXX-release file as well as a redhat-release file. 2004 // Because of this the XXX-release file needs to be searched for before the 2005 // redhat-release file. 2006 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the 2007 // search for redhat-release / SuSE-release needs to be before lsb-release. 2008 // Since the lsb-release file is the new standard it needs to be searched 2009 // before the older style release files. 2010 // Searching system-release (Red Hat) and os-release (other Linuxes) are a 2011 // next to last resort. The os-release file is a new standard that contains 2012 // distribution information and the system-release file seems to be an old 2013 // standard that has been replaced by the lsb-release and os-release files. 2014 // Searching for the debian_version file is the last resort. It contains 2015 // an informative string like "6.0.6" or "wheezy/sid". Because of this 2016 // "Debian " is printed before the contents of the debian_version file. 2017 2018 const char* distro_files[] = { 2019 "/etc/oracle-release", 2020 "/etc/mandriva-release", 2021 "/etc/mandrake-release", 2022 "/etc/sun-release", 2023 "/etc/redhat-release", 2024 "/etc/SuSE-release", 2025 "/etc/lsb-release", 2026 "/etc/turbolinux-release", 2027 "/etc/gentoo-release", 2028 "/etc/ltib-release", 2029 "/etc/angstrom-version", 2030 "/etc/system-release", 2031 "/etc/os-release", 2032 NULL }; 2033 2034 void os::Linux::print_distro_info(outputStream* st) { 2035 for (int i = 0;; i++) { 2036 const char* file = distro_files[i]; 2037 if (file == NULL) { 2038 break; // done 2039 } 2040 // If file prints, we found it. 2041 if (_print_ascii_file(file, st)) { 2042 return; 2043 } 2044 } 2045 2046 if (file_exists("/etc/debian_version")) { 2047 st->print("Debian "); 2048 _print_ascii_file("/etc/debian_version", st); 2049 } else { 2050 st->print("Linux"); 2051 } 2052 st->cr(); 2053 } 2054 2055 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) { 2056 char buf[256]; 2057 while (fgets(buf, sizeof(buf), fp)) { 2058 // Edit out extra stuff in expected format 2059 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) { 2060 char* ptr = strstr(buf, "\""); // the name is in quotes 2061 if (ptr != NULL) { 2062 ptr++; // go beyond first quote 2063 char* nl = strchr(ptr, '\"'); 2064 if (nl != NULL) *nl = '\0'; 2065 strncpy(distro, ptr, length); 2066 } else { 2067 ptr = strstr(buf, "="); 2068 ptr++; // go beyond equals then 2069 char* nl = strchr(ptr, '\n'); 2070 if (nl != NULL) *nl = '\0'; 2071 strncpy(distro, ptr, length); 2072 } 2073 return; 2074 } else if (get_first_line) { 2075 char* nl = strchr(buf, '\n'); 2076 if (nl != NULL) *nl = '\0'; 2077 strncpy(distro, buf, length); 2078 return; 2079 } 2080 } 2081 // print last line and close 2082 char* nl = strchr(buf, '\n'); 2083 if (nl != NULL) *nl = '\0'; 2084 strncpy(distro, buf, length); 2085 } 2086 2087 static void parse_os_info(char* distro, size_t length, const char* file) { 2088 FILE* fp = fopen(file, "r"); 2089 if (fp != NULL) { 2090 // if suse format, print out first line 2091 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0); 2092 parse_os_info_helper(fp, distro, length, get_first_line); 2093 fclose(fp); 2094 } 2095 } 2096 2097 void os::get_summary_os_info(char* buf, size_t buflen) { 2098 for (int i = 0;; i++) { 2099 const char* file = distro_files[i]; 2100 if (file == NULL) { 2101 break; // ran out of distro_files 2102 } 2103 if (file_exists(file)) { 2104 parse_os_info(buf, buflen, file); 2105 return; 2106 } 2107 } 2108 // special case for debian 2109 if (file_exists("/etc/debian_version")) { 2110 strncpy(buf, "Debian ", buflen); 2111 parse_os_info(&buf[7], buflen-7, "/etc/debian_version"); 2112 } else { 2113 strncpy(buf, "Linux", buflen); 2114 } 2115 } 2116 2117 void os::Linux::print_libversion_info(outputStream* st) { 2118 // libc, pthread 2119 st->print("libc:"); 2120 st->print("%s ", os::Linux::glibc_version()); 2121 st->print("%s ", os::Linux::libpthread_version()); 2122 st->cr(); 2123 } 2124 2125 void os::Linux::print_full_memory_info(outputStream* st) { 2126 st->print("\n/proc/meminfo:\n"); 2127 _print_ascii_file("/proc/meminfo", st); 2128 st->cr(); 2129 } 2130 2131 void os::Linux::print_container_info(outputStream* st) { 2132 if (!OSContainer::is_containerized()) { 2133 return; 2134 } 2135 2136 st->print("container (cgroup) information:\n"); 2137 2138 const char *p_ct = OSContainer::container_type(); 2139 st->print("container_type: %s\n", p_ct != NULL ? p_ct : "failed"); 2140 2141 char *p = OSContainer::cpu_cpuset_cpus(); 2142 st->print("cpu_cpuset_cpus: %s\n", p != NULL ? p : "failed"); 2143 free(p); 2144 2145 p = OSContainer::cpu_cpuset_memory_nodes(); 2146 st->print("cpu_memory_nodes: %s\n", p != NULL ? p : "failed"); 2147 free(p); 2148 2149 int i = OSContainer::active_processor_count(); 2150 if (i > 0) { 2151 st->print("active_processor_count: %d\n", i); 2152 } else { 2153 st->print("active_processor_count: failed\n"); 2154 } 2155 2156 i = OSContainer::cpu_quota(); 2157 st->print("cpu_quota: %d\n", i); 2158 2159 i = OSContainer::cpu_period(); 2160 st->print("cpu_period: %d\n", i); 2161 2162 i = OSContainer::cpu_shares(); 2163 st->print("cpu_shares: %d\n", i); 2164 2165 jlong j = OSContainer::memory_limit_in_bytes(); 2166 st->print("memory_limit_in_bytes: " JLONG_FORMAT "\n", j); 2167 2168 j = OSContainer::memory_and_swap_limit_in_bytes(); 2169 st->print("memory_and_swap_limit_in_bytes: " JLONG_FORMAT "\n", j); 2170 2171 j = OSContainer::memory_soft_limit_in_bytes(); 2172 st->print("memory_soft_limit_in_bytes: " JLONG_FORMAT "\n", j); 2173 2174 j = OSContainer::OSContainer::memory_usage_in_bytes(); 2175 st->print("memory_usage_in_bytes: " JLONG_FORMAT "\n", j); 2176 2177 j = OSContainer::OSContainer::memory_max_usage_in_bytes(); 2178 st->print("memory_max_usage_in_bytes: " JLONG_FORMAT "\n", j); 2179 st->cr(); 2180 } 2181 2182 void os::print_memory_info(outputStream* st) { 2183 2184 st->print("Memory:"); 2185 st->print(" %dk page", os::vm_page_size()>>10); 2186 2187 // values in struct sysinfo are "unsigned long" 2188 struct sysinfo si; 2189 sysinfo(&si); 2190 2191 st->print(", physical " UINT64_FORMAT "k", 2192 os::physical_memory() >> 10); 2193 st->print("(" UINT64_FORMAT "k free)", 2194 os::available_memory() >> 10); 2195 st->print(", swap " UINT64_FORMAT "k", 2196 ((jlong)si.totalswap * si.mem_unit) >> 10); 2197 st->print("(" UINT64_FORMAT "k free)", 2198 ((jlong)si.freeswap * si.mem_unit) >> 10); 2199 st->cr(); 2200 } 2201 2202 // Print the first "model name" line and the first "flags" line 2203 // that we find and nothing more. We assume "model name" comes 2204 // before "flags" so if we find a second "model name", then the 2205 // "flags" field is considered missing. 2206 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) { 2207 #if defined(IA32) || defined(AMD64) 2208 // Other platforms have less repetitive cpuinfo files 2209 FILE *fp = fopen("/proc/cpuinfo", "r"); 2210 if (fp) { 2211 while (!feof(fp)) { 2212 if (fgets(buf, buflen, fp)) { 2213 // Assume model name comes before flags 2214 bool model_name_printed = false; 2215 if (strstr(buf, "model name") != NULL) { 2216 if (!model_name_printed) { 2217 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n"); 2218 st->print_raw(buf); 2219 model_name_printed = true; 2220 } else { 2221 // model name printed but not flags? Odd, just return 2222 fclose(fp); 2223 return true; 2224 } 2225 } 2226 // print the flags line too 2227 if (strstr(buf, "flags") != NULL) { 2228 st->print_raw(buf); 2229 fclose(fp); 2230 return true; 2231 } 2232 } 2233 } 2234 fclose(fp); 2235 } 2236 #endif // x86 platforms 2237 return false; 2238 } 2239 2240 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) { 2241 // Only print the model name if the platform provides this as a summary 2242 if (!print_model_name_and_flags(st, buf, buflen)) { 2243 st->print("\n/proc/cpuinfo:\n"); 2244 if (!_print_ascii_file("/proc/cpuinfo", st)) { 2245 st->print_cr(" <Not Available>"); 2246 } 2247 } 2248 } 2249 2250 #if defined(AMD64) || defined(IA32) || defined(X32) 2251 const char* search_string = "model name"; 2252 #elif defined(M68K) 2253 const char* search_string = "CPU"; 2254 #elif defined(PPC64) 2255 const char* search_string = "cpu"; 2256 #elif defined(S390) 2257 const char* search_string = "processor"; 2258 #elif defined(SPARC) 2259 const char* search_string = "cpu"; 2260 #else 2261 const char* search_string = "Processor"; 2262 #endif 2263 2264 // Parses the cpuinfo file for string representing the model name. 2265 void os::get_summary_cpu_info(char* cpuinfo, size_t length) { 2266 FILE* fp = fopen("/proc/cpuinfo", "r"); 2267 if (fp != NULL) { 2268 while (!feof(fp)) { 2269 char buf[256]; 2270 if (fgets(buf, sizeof(buf), fp)) { 2271 char* start = strstr(buf, search_string); 2272 if (start != NULL) { 2273 char *ptr = start + strlen(search_string); 2274 char *end = buf + strlen(buf); 2275 while (ptr != end) { 2276 // skip whitespace and colon for the rest of the name. 2277 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') { 2278 break; 2279 } 2280 ptr++; 2281 } 2282 if (ptr != end) { 2283 // reasonable string, get rid of newline and keep the rest 2284 char* nl = strchr(buf, '\n'); 2285 if (nl != NULL) *nl = '\0'; 2286 strncpy(cpuinfo, ptr, length); 2287 fclose(fp); 2288 return; 2289 } 2290 } 2291 } 2292 } 2293 fclose(fp); 2294 } 2295 // cpuinfo not found or parsing failed, just print generic string. The entire 2296 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86) 2297 #if defined(AARCH64) 2298 strncpy(cpuinfo, "AArch64", length); 2299 #elif defined(AMD64) 2300 strncpy(cpuinfo, "x86_64", length); 2301 #elif defined(ARM) // Order wrt. AARCH64 is relevant! 2302 strncpy(cpuinfo, "ARM", length); 2303 #elif defined(IA32) 2304 strncpy(cpuinfo, "x86_32", length); 2305 #elif defined(IA64) 2306 strncpy(cpuinfo, "IA64", length); 2307 #elif defined(PPC) 2308 strncpy(cpuinfo, "PPC64", length); 2309 #elif defined(S390) 2310 strncpy(cpuinfo, "S390", length); 2311 #elif defined(SPARC) 2312 strncpy(cpuinfo, "sparcv9", length); 2313 #elif defined(ZERO_LIBARCH) 2314 strncpy(cpuinfo, ZERO_LIBARCH, length); 2315 #else 2316 strncpy(cpuinfo, "unknown", length); 2317 #endif 2318 } 2319 2320 static void print_signal_handler(outputStream* st, int sig, 2321 char* buf, size_t buflen); 2322 2323 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 2324 st->print_cr("Signal Handlers:"); 2325 print_signal_handler(st, SIGSEGV, buf, buflen); 2326 print_signal_handler(st, SIGBUS , buf, buflen); 2327 print_signal_handler(st, SIGFPE , buf, buflen); 2328 print_signal_handler(st, SIGPIPE, buf, buflen); 2329 print_signal_handler(st, SIGXFSZ, buf, buflen); 2330 print_signal_handler(st, SIGILL , buf, buflen); 2331 print_signal_handler(st, SR_signum, buf, buflen); 2332 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 2333 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 2334 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 2335 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 2336 #if defined(PPC64) 2337 print_signal_handler(st, SIGTRAP, buf, buflen); 2338 #endif 2339 } 2340 2341 static char saved_jvm_path[MAXPATHLEN] = {0}; 2342 2343 // Find the full path to the current module, libjvm.so 2344 void os::jvm_path(char *buf, jint buflen) { 2345 // Error checking. 2346 if (buflen < MAXPATHLEN) { 2347 assert(false, "must use a large-enough buffer"); 2348 buf[0] = '\0'; 2349 return; 2350 } 2351 // Lazy resolve the path to current module. 2352 if (saved_jvm_path[0] != 0) { 2353 strcpy(buf, saved_jvm_path); 2354 return; 2355 } 2356 2357 char dli_fname[MAXPATHLEN]; 2358 bool ret = dll_address_to_library_name( 2359 CAST_FROM_FN_PTR(address, os::jvm_path), 2360 dli_fname, sizeof(dli_fname), NULL); 2361 assert(ret, "cannot locate libjvm"); 2362 char *rp = NULL; 2363 if (ret && dli_fname[0] != '\0') { 2364 rp = os::Posix::realpath(dli_fname, buf, buflen); 2365 } 2366 if (rp == NULL) { 2367 return; 2368 } 2369 2370 if (Arguments::sun_java_launcher_is_altjvm()) { 2371 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 2372 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so". 2373 // If "/jre/lib/" appears at the right place in the string, then 2374 // assume we are installed in a JDK and we're done. Otherwise, check 2375 // for a JAVA_HOME environment variable and fix up the path so it 2376 // looks like libjvm.so is installed there (append a fake suffix 2377 // hotspot/libjvm.so). 2378 const char *p = buf + strlen(buf) - 1; 2379 for (int count = 0; p > buf && count < 5; ++count) { 2380 for (--p; p > buf && *p != '/'; --p) 2381 /* empty */ ; 2382 } 2383 2384 if (strncmp(p, "/jre/lib/", 9) != 0) { 2385 // Look for JAVA_HOME in the environment. 2386 char* java_home_var = ::getenv("JAVA_HOME"); 2387 if (java_home_var != NULL && java_home_var[0] != 0) { 2388 char* jrelib_p; 2389 int len; 2390 2391 // Check the current module name "libjvm.so". 2392 p = strrchr(buf, '/'); 2393 if (p == NULL) { 2394 return; 2395 } 2396 assert(strstr(p, "/libjvm") == p, "invalid library name"); 2397 2398 rp = os::Posix::realpath(java_home_var, buf, buflen); 2399 if (rp == NULL) { 2400 return; 2401 } 2402 2403 // determine if this is a legacy image or modules image 2404 // modules image doesn't have "jre" subdirectory 2405 len = strlen(buf); 2406 assert(len < buflen, "Ran out of buffer room"); 2407 jrelib_p = buf + len; 2408 snprintf(jrelib_p, buflen-len, "/jre/lib"); 2409 if (0 != access(buf, F_OK)) { 2410 snprintf(jrelib_p, buflen-len, "/lib"); 2411 } 2412 2413 if (0 == access(buf, F_OK)) { 2414 // Use current module name "libjvm.so" 2415 len = strlen(buf); 2416 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so"); 2417 } else { 2418 // Go back to path of .so 2419 rp = os::Posix::realpath(dli_fname, buf, buflen); 2420 if (rp == NULL) { 2421 return; 2422 } 2423 } 2424 } 2425 } 2426 } 2427 2428 strncpy(saved_jvm_path, buf, MAXPATHLEN); 2429 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 2430 } 2431 2432 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 2433 // no prefix required, not even "_" 2434 } 2435 2436 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 2437 // no suffix required 2438 } 2439 2440 //////////////////////////////////////////////////////////////////////////////// 2441 // sun.misc.Signal support 2442 2443 static volatile jint sigint_count = 0; 2444 2445 static void UserHandler(int sig, void *siginfo, void *context) { 2446 // 4511530 - sem_post is serialized and handled by the manager thread. When 2447 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 2448 // don't want to flood the manager thread with sem_post requests. 2449 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 2450 return; 2451 } 2452 2453 // Ctrl-C is pressed during error reporting, likely because the error 2454 // handler fails to abort. Let VM die immediately. 2455 if (sig == SIGINT && VMError::is_error_reported()) { 2456 os::die(); 2457 } 2458 2459 os::signal_notify(sig); 2460 } 2461 2462 void* os::user_handler() { 2463 return CAST_FROM_FN_PTR(void*, UserHandler); 2464 } 2465 2466 static struct timespec create_semaphore_timespec(unsigned int sec, int nsec) { 2467 struct timespec ts; 2468 // Semaphore's are always associated with CLOCK_REALTIME 2469 os::Linux::clock_gettime(CLOCK_REALTIME, &ts); 2470 // see os_posix.cpp for discussion on overflow checking 2471 if (sec >= MAX_SECS) { 2472 ts.tv_sec += MAX_SECS; 2473 ts.tv_nsec = 0; 2474 } else { 2475 ts.tv_sec += sec; 2476 ts.tv_nsec += nsec; 2477 if (ts.tv_nsec >= NANOSECS_PER_SEC) { 2478 ts.tv_nsec -= NANOSECS_PER_SEC; 2479 ++ts.tv_sec; // note: this must be <= max_secs 2480 } 2481 } 2482 2483 return ts; 2484 } 2485 2486 extern "C" { 2487 typedef void (*sa_handler_t)(int); 2488 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 2489 } 2490 2491 void* os::signal(int signal_number, void* handler) { 2492 struct sigaction sigAct, oldSigAct; 2493 2494 sigfillset(&(sigAct.sa_mask)); 2495 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 2496 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 2497 2498 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 2499 // -1 means registration failed 2500 return (void *)-1; 2501 } 2502 2503 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 2504 } 2505 2506 void os::signal_raise(int signal_number) { 2507 ::raise(signal_number); 2508 } 2509 2510 // The following code is moved from os.cpp for making this 2511 // code platform specific, which it is by its very nature. 2512 2513 // Will be modified when max signal is changed to be dynamic 2514 int os::sigexitnum_pd() { 2515 return NSIG; 2516 } 2517 2518 // a counter for each possible signal value 2519 static volatile jint pending_signals[NSIG+1] = { 0 }; 2520 2521 // Linux(POSIX) specific hand shaking semaphore. 2522 static Semaphore* sig_sem = NULL; 2523 static PosixSemaphore sr_semaphore; 2524 2525 void os::signal_init_pd() { 2526 // Initialize signal structures 2527 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2528 2529 // Initialize signal semaphore 2530 sig_sem = new Semaphore(); 2531 } 2532 2533 void os::signal_notify(int sig) { 2534 if (sig_sem != NULL) { 2535 Atomic::inc(&pending_signals[sig]); 2536 sig_sem->signal(); 2537 } else { 2538 // Signal thread is not created with ReduceSignalUsage and signal_init_pd 2539 // initialization isn't called. 2540 assert(ReduceSignalUsage, "signal semaphore should be created"); 2541 } 2542 } 2543 2544 static int check_pending_signals() { 2545 Atomic::store(0, &sigint_count); 2546 for (;;) { 2547 for (int i = 0; i < NSIG + 1; i++) { 2548 jint n = pending_signals[i]; 2549 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2550 return i; 2551 } 2552 } 2553 JavaThread *thread = JavaThread::current(); 2554 ThreadBlockInVM tbivm(thread); 2555 2556 bool threadIsSuspended; 2557 do { 2558 thread->set_suspend_equivalent(); 2559 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2560 sig_sem->wait(); 2561 2562 // were we externally suspended while we were waiting? 2563 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2564 if (threadIsSuspended) { 2565 // The semaphore has been incremented, but while we were waiting 2566 // another thread suspended us. We don't want to continue running 2567 // while suspended because that would surprise the thread that 2568 // suspended us. 2569 sig_sem->signal(); 2570 2571 thread->java_suspend_self(); 2572 } 2573 } while (threadIsSuspended); 2574 } 2575 } 2576 2577 int os::signal_wait() { 2578 return check_pending_signals(); 2579 } 2580 2581 //////////////////////////////////////////////////////////////////////////////// 2582 // Virtual Memory 2583 2584 int os::vm_page_size() { 2585 // Seems redundant as all get out 2586 assert(os::Linux::page_size() != -1, "must call os::init"); 2587 return os::Linux::page_size(); 2588 } 2589 2590 // Solaris allocates memory by pages. 2591 int os::vm_allocation_granularity() { 2592 assert(os::Linux::page_size() != -1, "must call os::init"); 2593 return os::Linux::page_size(); 2594 } 2595 2596 // Rationale behind this function: 2597 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2598 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2599 // samples for JITted code. Here we create private executable mapping over the code cache 2600 // and then we can use standard (well, almost, as mapping can change) way to provide 2601 // info for the reporting script by storing timestamp and location of symbol 2602 void linux_wrap_code(char* base, size_t size) { 2603 static volatile jint cnt = 0; 2604 2605 if (!UseOprofile) { 2606 return; 2607 } 2608 2609 char buf[PATH_MAX+1]; 2610 int num = Atomic::add(1, &cnt); 2611 2612 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d", 2613 os::get_temp_directory(), os::current_process_id(), num); 2614 unlink(buf); 2615 2616 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2617 2618 if (fd != -1) { 2619 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2620 if (rv != (off_t)-1) { 2621 if (::write(fd, "", 1) == 1) { 2622 mmap(base, size, 2623 PROT_READ|PROT_WRITE|PROT_EXEC, 2624 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2625 } 2626 } 2627 ::close(fd); 2628 unlink(buf); 2629 } 2630 } 2631 2632 static bool recoverable_mmap_error(int err) { 2633 // See if the error is one we can let the caller handle. This 2634 // list of errno values comes from JBS-6843484. I can't find a 2635 // Linux man page that documents this specific set of errno 2636 // values so while this list currently matches Solaris, it may 2637 // change as we gain experience with this failure mode. 2638 switch (err) { 2639 case EBADF: 2640 case EINVAL: 2641 case ENOTSUP: 2642 // let the caller deal with these errors 2643 return true; 2644 2645 default: 2646 // Any remaining errors on this OS can cause our reserved mapping 2647 // to be lost. That can cause confusion where different data 2648 // structures think they have the same memory mapped. The worst 2649 // scenario is if both the VM and a library think they have the 2650 // same memory mapped. 2651 return false; 2652 } 2653 } 2654 2655 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2656 int err) { 2657 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2658 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec, 2659 os::strerror(err), err); 2660 } 2661 2662 static void warn_fail_commit_memory(char* addr, size_t size, 2663 size_t alignment_hint, bool exec, 2664 int err) { 2665 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2666 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, 2667 alignment_hint, exec, os::strerror(err), err); 2668 } 2669 2670 // NOTE: Linux kernel does not really reserve the pages for us. 2671 // All it does is to check if there are enough free pages 2672 // left at the time of mmap(). This could be a potential 2673 // problem. 2674 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) { 2675 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2676 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2677 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2678 if (res != (uintptr_t) MAP_FAILED) { 2679 if (UseNUMAInterleaving) { 2680 numa_make_global(addr, size); 2681 } 2682 return 0; 2683 } 2684 2685 int err = errno; // save errno from mmap() call above 2686 2687 if (!recoverable_mmap_error(err)) { 2688 warn_fail_commit_memory(addr, size, exec, err); 2689 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory."); 2690 } 2691 2692 return err; 2693 } 2694 2695 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2696 return os::Linux::commit_memory_impl(addr, size, exec) == 0; 2697 } 2698 2699 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2700 const char* mesg) { 2701 assert(mesg != NULL, "mesg must be specified"); 2702 int err = os::Linux::commit_memory_impl(addr, size, exec); 2703 if (err != 0) { 2704 // the caller wants all commit errors to exit with the specified mesg: 2705 warn_fail_commit_memory(addr, size, exec, err); 2706 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2707 } 2708 } 2709 2710 // Define MAP_HUGETLB here so we can build HotSpot on old systems. 2711 #ifndef MAP_HUGETLB 2712 #define MAP_HUGETLB 0x40000 2713 #endif 2714 2715 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems. 2716 #ifndef MADV_HUGEPAGE 2717 #define MADV_HUGEPAGE 14 2718 #endif 2719 2720 int os::Linux::commit_memory_impl(char* addr, size_t size, 2721 size_t alignment_hint, bool exec) { 2722 int err = os::Linux::commit_memory_impl(addr, size, exec); 2723 if (err == 0) { 2724 realign_memory(addr, size, alignment_hint); 2725 } 2726 return err; 2727 } 2728 2729 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2730 bool exec) { 2731 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0; 2732 } 2733 2734 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2735 size_t alignment_hint, bool exec, 2736 const char* mesg) { 2737 assert(mesg != NULL, "mesg must be specified"); 2738 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec); 2739 if (err != 0) { 2740 // the caller wants all commit errors to exit with the specified mesg: 2741 warn_fail_commit_memory(addr, size, alignment_hint, exec, err); 2742 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2743 } 2744 } 2745 2746 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2747 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) { 2748 // We don't check the return value: madvise(MADV_HUGEPAGE) may not 2749 // be supported or the memory may already be backed by huge pages. 2750 ::madvise(addr, bytes, MADV_HUGEPAGE); 2751 } 2752 } 2753 2754 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2755 // This method works by doing an mmap over an existing mmaping and effectively discarding 2756 // the existing pages. However it won't work for SHM-based large pages that cannot be 2757 // uncommitted at all. We don't do anything in this case to avoid creating a segment with 2758 // small pages on top of the SHM segment. This method always works for small pages, so we 2759 // allow that in any case. 2760 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) { 2761 commit_memory(addr, bytes, alignment_hint, !ExecMem); 2762 } 2763 } 2764 2765 void os::numa_make_global(char *addr, size_t bytes) { 2766 Linux::numa_interleave_memory(addr, bytes); 2767 } 2768 2769 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the 2770 // bind policy to MPOL_PREFERRED for the current thread. 2771 #define USE_MPOL_PREFERRED 0 2772 2773 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2774 // To make NUMA and large pages more robust when both enabled, we need to ease 2775 // the requirements on where the memory should be allocated. MPOL_BIND is the 2776 // default policy and it will force memory to be allocated on the specified 2777 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on 2778 // the specified node, but will not force it. Using this policy will prevent 2779 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no 2780 // free large pages. 2781 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED); 2782 Linux::numa_tonode_memory(addr, bytes, lgrp_hint); 2783 } 2784 2785 bool os::numa_topology_changed() { return false; } 2786 2787 size_t os::numa_get_groups_num() { 2788 // Return just the number of nodes in which it's possible to allocate memory 2789 // (in numa terminology, configured nodes). 2790 return Linux::numa_num_configured_nodes(); 2791 } 2792 2793 int os::numa_get_group_id() { 2794 int cpu_id = Linux::sched_getcpu(); 2795 if (cpu_id != -1) { 2796 int lgrp_id = Linux::get_node_by_cpu(cpu_id); 2797 if (lgrp_id != -1) { 2798 return lgrp_id; 2799 } 2800 } 2801 return 0; 2802 } 2803 2804 int os::Linux::get_existing_num_nodes() { 2805 size_t node; 2806 size_t highest_node_number = Linux::numa_max_node(); 2807 int num_nodes = 0; 2808 2809 // Get the total number of nodes in the system including nodes without memory. 2810 for (node = 0; node <= highest_node_number; node++) { 2811 if (isnode_in_existing_nodes(node)) { 2812 num_nodes++; 2813 } 2814 } 2815 return num_nodes; 2816 } 2817 2818 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2819 size_t highest_node_number = Linux::numa_max_node(); 2820 size_t i = 0; 2821 2822 // Map all node ids in which is possible to allocate memory. Also nodes are 2823 // not always consecutively available, i.e. available from 0 to the highest 2824 // node number. 2825 for (size_t node = 0; node <= highest_node_number; node++) { 2826 if (Linux::isnode_in_configured_nodes(node)) { 2827 ids[i++] = node; 2828 } 2829 } 2830 return i; 2831 } 2832 2833 bool os::get_page_info(char *start, page_info* info) { 2834 return false; 2835 } 2836 2837 char *os::scan_pages(char *start, char* end, page_info* page_expected, 2838 page_info* page_found) { 2839 return end; 2840 } 2841 2842 2843 int os::Linux::sched_getcpu_syscall(void) { 2844 unsigned int cpu = 0; 2845 int retval = -1; 2846 2847 #if defined(IA32) 2848 #ifndef SYS_getcpu 2849 #define SYS_getcpu 318 2850 #endif 2851 retval = syscall(SYS_getcpu, &cpu, NULL, NULL); 2852 #elif defined(AMD64) 2853 // Unfortunately we have to bring all these macros here from vsyscall.h 2854 // to be able to compile on old linuxes. 2855 #define __NR_vgetcpu 2 2856 #define VSYSCALL_START (-10UL << 20) 2857 #define VSYSCALL_SIZE 1024 2858 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr)) 2859 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache); 2860 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu); 2861 retval = vgetcpu(&cpu, NULL, NULL); 2862 #endif 2863 2864 return (retval == -1) ? retval : cpu; 2865 } 2866 2867 void os::Linux::sched_getcpu_init() { 2868 // sched_getcpu() should be in libc. 2869 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2870 dlsym(RTLD_DEFAULT, "sched_getcpu"))); 2871 2872 // If it's not, try a direct syscall. 2873 if (sched_getcpu() == -1) { 2874 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2875 (void*)&sched_getcpu_syscall)); 2876 } 2877 } 2878 2879 // Something to do with the numa-aware allocator needs these symbols 2880 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { } 2881 extern "C" JNIEXPORT void numa_error(char *where) { } 2882 2883 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails 2884 // load symbol from base version instead. 2885 void* os::Linux::libnuma_dlsym(void* handle, const char *name) { 2886 void *f = dlvsym(handle, name, "libnuma_1.1"); 2887 if (f == NULL) { 2888 f = dlsym(handle, name); 2889 } 2890 return f; 2891 } 2892 2893 // Handle request to load libnuma symbol version 1.2 (API v2) only. 2894 // Return NULL if the symbol is not defined in this particular version. 2895 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) { 2896 return dlvsym(handle, name, "libnuma_1.2"); 2897 } 2898 2899 bool os::Linux::libnuma_init() { 2900 if (sched_getcpu() != -1) { // Requires sched_getcpu() support 2901 void *handle = dlopen("libnuma.so.1", RTLD_LAZY); 2902 if (handle != NULL) { 2903 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, 2904 libnuma_dlsym(handle, "numa_node_to_cpus"))); 2905 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, 2906 libnuma_dlsym(handle, "numa_max_node"))); 2907 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t, 2908 libnuma_dlsym(handle, "numa_num_configured_nodes"))); 2909 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, 2910 libnuma_dlsym(handle, "numa_available"))); 2911 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, 2912 libnuma_dlsym(handle, "numa_tonode_memory"))); 2913 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t, 2914 libnuma_dlsym(handle, "numa_interleave_memory"))); 2915 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t, 2916 libnuma_v2_dlsym(handle, "numa_interleave_memory"))); 2917 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t, 2918 libnuma_dlsym(handle, "numa_set_bind_policy"))); 2919 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t, 2920 libnuma_dlsym(handle, "numa_bitmask_isbitset"))); 2921 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t, 2922 libnuma_dlsym(handle, "numa_distance"))); 2923 2924 if (numa_available() != -1) { 2925 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); 2926 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr")); 2927 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr")); 2928 // Create an index -> node mapping, since nodes are not always consecutive 2929 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2930 rebuild_nindex_to_node_map(); 2931 // Create a cpu -> node mapping 2932 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2933 rebuild_cpu_to_node_map(); 2934 return true; 2935 } 2936 } 2937 } 2938 return false; 2939 } 2940 2941 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 2942 // Creating guard page is very expensive. Java thread has HotSpot 2943 // guard pages, only enable glibc guard page for non-Java threads. 2944 // (Remember: compiler thread is a Java thread, too!) 2945 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size()); 2946 } 2947 2948 void os::Linux::rebuild_nindex_to_node_map() { 2949 int highest_node_number = Linux::numa_max_node(); 2950 2951 nindex_to_node()->clear(); 2952 for (int node = 0; node <= highest_node_number; node++) { 2953 if (Linux::isnode_in_existing_nodes(node)) { 2954 nindex_to_node()->append(node); 2955 } 2956 } 2957 } 2958 2959 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. 2960 // The table is later used in get_node_by_cpu(). 2961 void os::Linux::rebuild_cpu_to_node_map() { 2962 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure 2963 // in libnuma (possible values are starting from 16, 2964 // and continuing up with every other power of 2, but less 2965 // than the maximum number of CPUs supported by kernel), and 2966 // is a subject to change (in libnuma version 2 the requirements 2967 // are more reasonable) we'll just hardcode the number they use 2968 // in the library. 2969 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT; 2970 2971 size_t cpu_num = processor_count(); 2972 size_t cpu_map_size = NCPUS / BitsPerCLong; 2973 size_t cpu_map_valid_size = 2974 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size); 2975 2976 cpu_to_node()->clear(); 2977 cpu_to_node()->at_grow(cpu_num - 1); 2978 2979 size_t node_num = get_existing_num_nodes(); 2980 2981 int distance = 0; 2982 int closest_distance = INT_MAX; 2983 int closest_node = 0; 2984 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal); 2985 for (size_t i = 0; i < node_num; i++) { 2986 // Check if node is configured (not a memory-less node). If it is not, find 2987 // the closest configured node. 2988 if (!isnode_in_configured_nodes(nindex_to_node()->at(i))) { 2989 closest_distance = INT_MAX; 2990 // Check distance from all remaining nodes in the system. Ignore distance 2991 // from itself and from another non-configured node. 2992 for (size_t m = 0; m < node_num; m++) { 2993 if (m != i && isnode_in_configured_nodes(nindex_to_node()->at(m))) { 2994 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m)); 2995 // If a closest node is found, update. There is always at least one 2996 // configured node in the system so there is always at least one node 2997 // close. 2998 if (distance != 0 && distance < closest_distance) { 2999 closest_distance = distance; 3000 closest_node = nindex_to_node()->at(m); 3001 } 3002 } 3003 } 3004 } else { 3005 // Current node is already a configured node. 3006 closest_node = nindex_to_node()->at(i); 3007 } 3008 3009 // Get cpus from the original node and map them to the closest node. If node 3010 // is a configured node (not a memory-less node), then original node and 3011 // closest node are the same. 3012 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { 3013 for (size_t j = 0; j < cpu_map_valid_size; j++) { 3014 if (cpu_map[j] != 0) { 3015 for (size_t k = 0; k < BitsPerCLong; k++) { 3016 if (cpu_map[j] & (1UL << k)) { 3017 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node); 3018 } 3019 } 3020 } 3021 } 3022 } 3023 } 3024 FREE_C_HEAP_ARRAY(unsigned long, cpu_map); 3025 } 3026 3027 int os::Linux::get_node_by_cpu(int cpu_id) { 3028 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { 3029 return cpu_to_node()->at(cpu_id); 3030 } 3031 return -1; 3032 } 3033 3034 GrowableArray<int>* os::Linux::_cpu_to_node; 3035 GrowableArray<int>* os::Linux::_nindex_to_node; 3036 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu; 3037 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus; 3038 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node; 3039 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes; 3040 os::Linux::numa_available_func_t os::Linux::_numa_available; 3041 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory; 3042 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory; 3043 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2; 3044 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy; 3045 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset; 3046 os::Linux::numa_distance_func_t os::Linux::_numa_distance; 3047 unsigned long* os::Linux::_numa_all_nodes; 3048 struct bitmask* os::Linux::_numa_all_nodes_ptr; 3049 struct bitmask* os::Linux::_numa_nodes_ptr; 3050 3051 bool os::pd_uncommit_memory(char* addr, size_t size) { 3052 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 3053 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 3054 return res != (uintptr_t) MAP_FAILED; 3055 } 3056 3057 static address get_stack_commited_bottom(address bottom, size_t size) { 3058 address nbot = bottom; 3059 address ntop = bottom + size; 3060 3061 size_t page_sz = os::vm_page_size(); 3062 unsigned pages = size / page_sz; 3063 3064 unsigned char vec[1]; 3065 unsigned imin = 1, imax = pages + 1, imid; 3066 int mincore_return_value = 0; 3067 3068 assert(imin <= imax, "Unexpected page size"); 3069 3070 while (imin < imax) { 3071 imid = (imax + imin) / 2; 3072 nbot = ntop - (imid * page_sz); 3073 3074 // Use a trick with mincore to check whether the page is mapped or not. 3075 // mincore sets vec to 1 if page resides in memory and to 0 if page 3076 // is swapped output but if page we are asking for is unmapped 3077 // it returns -1,ENOMEM 3078 mincore_return_value = mincore(nbot, page_sz, vec); 3079 3080 if (mincore_return_value == -1) { 3081 // Page is not mapped go up 3082 // to find first mapped page 3083 if (errno != EAGAIN) { 3084 assert(errno == ENOMEM, "Unexpected mincore errno"); 3085 imax = imid; 3086 } 3087 } else { 3088 // Page is mapped go down 3089 // to find first not mapped page 3090 imin = imid + 1; 3091 } 3092 } 3093 3094 nbot = nbot + page_sz; 3095 3096 // Adjust stack bottom one page up if last checked page is not mapped 3097 if (mincore_return_value == -1) { 3098 nbot = nbot + page_sz; 3099 } 3100 3101 return nbot; 3102 } 3103 3104 3105 // Linux uses a growable mapping for the stack, and if the mapping for 3106 // the stack guard pages is not removed when we detach a thread the 3107 // stack cannot grow beyond the pages where the stack guard was 3108 // mapped. If at some point later in the process the stack expands to 3109 // that point, the Linux kernel cannot expand the stack any further 3110 // because the guard pages are in the way, and a segfault occurs. 3111 // 3112 // However, it's essential not to split the stack region by unmapping 3113 // a region (leaving a hole) that's already part of the stack mapping, 3114 // so if the stack mapping has already grown beyond the guard pages at 3115 // the time we create them, we have to truncate the stack mapping. 3116 // So, we need to know the extent of the stack mapping when 3117 // create_stack_guard_pages() is called. 3118 3119 // We only need this for stacks that are growable: at the time of 3120 // writing thread stacks don't use growable mappings (i.e. those 3121 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this 3122 // only applies to the main thread. 3123 3124 // If the (growable) stack mapping already extends beyond the point 3125 // where we're going to put our guard pages, truncate the mapping at 3126 // that point by munmap()ping it. This ensures that when we later 3127 // munmap() the guard pages we don't leave a hole in the stack 3128 // mapping. This only affects the main/primordial thread 3129 3130 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 3131 if (os::is_primordial_thread()) { 3132 // As we manually grow stack up to bottom inside create_attached_thread(), 3133 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and 3134 // we don't need to do anything special. 3135 // Check it first, before calling heavy function. 3136 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom(); 3137 unsigned char vec[1]; 3138 3139 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) { 3140 // Fallback to slow path on all errors, including EAGAIN 3141 stack_extent = (uintptr_t) get_stack_commited_bottom( 3142 os::Linux::initial_thread_stack_bottom(), 3143 (size_t)addr - stack_extent); 3144 } 3145 3146 if (stack_extent < (uintptr_t)addr) { 3147 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent)); 3148 } 3149 } 3150 3151 return os::commit_memory(addr, size, !ExecMem); 3152 } 3153 3154 // If this is a growable mapping, remove the guard pages entirely by 3155 // munmap()ping them. If not, just call uncommit_memory(). This only 3156 // affects the main/primordial thread, but guard against future OS changes. 3157 // It's safe to always unmap guard pages for primordial thread because we 3158 // always place it right after end of the mapped region. 3159 3160 bool os::remove_stack_guard_pages(char* addr, size_t size) { 3161 uintptr_t stack_extent, stack_base; 3162 3163 if (os::is_primordial_thread()) { 3164 return ::munmap(addr, size) == 0; 3165 } 3166 3167 return os::uncommit_memory(addr, size); 3168 } 3169 3170 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 3171 // at 'requested_addr'. If there are existing memory mappings at the same 3172 // location, however, they will be overwritten. If 'fixed' is false, 3173 // 'requested_addr' is only treated as a hint, the return value may or 3174 // may not start from the requested address. Unlike Linux mmap(), this 3175 // function returns NULL to indicate failure. 3176 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 3177 char * addr; 3178 int flags; 3179 3180 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 3181 if (fixed) { 3182 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address"); 3183 flags |= MAP_FIXED; 3184 } 3185 3186 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 3187 // touch an uncommitted page. Otherwise, the read/write might 3188 // succeed if we have enough swap space to back the physical page. 3189 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 3190 flags, -1, 0); 3191 3192 return addr == MAP_FAILED ? NULL : addr; 3193 } 3194 3195 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address 3196 // (req_addr != NULL) or with a given alignment. 3197 // - bytes shall be a multiple of alignment. 3198 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3199 // - alignment sets the alignment at which memory shall be allocated. 3200 // It must be a multiple of allocation granularity. 3201 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3202 // req_addr or NULL. 3203 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) { 3204 3205 size_t extra_size = bytes; 3206 if (req_addr == NULL && alignment > 0) { 3207 extra_size += alignment; 3208 } 3209 3210 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE, 3211 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 3212 -1, 0); 3213 if (start == MAP_FAILED) { 3214 start = NULL; 3215 } else { 3216 if (req_addr != NULL) { 3217 if (start != req_addr) { 3218 ::munmap(start, extra_size); 3219 start = NULL; 3220 } 3221 } else { 3222 char* const start_aligned = align_up(start, alignment); 3223 char* const end_aligned = start_aligned + bytes; 3224 char* const end = start + extra_size; 3225 if (start_aligned > start) { 3226 ::munmap(start, start_aligned - start); 3227 } 3228 if (end_aligned < end) { 3229 ::munmap(end_aligned, end - end_aligned); 3230 } 3231 start = start_aligned; 3232 } 3233 } 3234 return start; 3235 } 3236 3237 static int anon_munmap(char * addr, size_t size) { 3238 return ::munmap(addr, size) == 0; 3239 } 3240 3241 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 3242 size_t alignment_hint) { 3243 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 3244 } 3245 3246 bool os::pd_release_memory(char* addr, size_t size) { 3247 return anon_munmap(addr, size); 3248 } 3249 3250 static bool linux_mprotect(char* addr, size_t size, int prot) { 3251 // Linux wants the mprotect address argument to be page aligned. 3252 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size()); 3253 3254 // According to SUSv3, mprotect() should only be used with mappings 3255 // established by mmap(), and mmap() always maps whole pages. Unaligned 3256 // 'addr' likely indicates problem in the VM (e.g. trying to change 3257 // protection of malloc'ed or statically allocated memory). Check the 3258 // caller if you hit this assert. 3259 assert(addr == bottom, "sanity check"); 3260 3261 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size()); 3262 return ::mprotect(bottom, size, prot) == 0; 3263 } 3264 3265 // Set protections specified 3266 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 3267 bool is_committed) { 3268 unsigned int p = 0; 3269 switch (prot) { 3270 case MEM_PROT_NONE: p = PROT_NONE; break; 3271 case MEM_PROT_READ: p = PROT_READ; break; 3272 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 3273 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 3274 default: 3275 ShouldNotReachHere(); 3276 } 3277 // is_committed is unused. 3278 return linux_mprotect(addr, bytes, p); 3279 } 3280 3281 bool os::guard_memory(char* addr, size_t size) { 3282 return linux_mprotect(addr, size, PROT_NONE); 3283 } 3284 3285 bool os::unguard_memory(char* addr, size_t size) { 3286 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE); 3287 } 3288 3289 bool os::Linux::transparent_huge_pages_sanity_check(bool warn, 3290 size_t page_size) { 3291 bool result = false; 3292 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE, 3293 MAP_ANONYMOUS|MAP_PRIVATE, 3294 -1, 0); 3295 if (p != MAP_FAILED) { 3296 void *aligned_p = align_up(p, page_size); 3297 3298 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0; 3299 3300 munmap(p, page_size * 2); 3301 } 3302 3303 if (warn && !result) { 3304 warning("TransparentHugePages is not supported by the operating system."); 3305 } 3306 3307 return result; 3308 } 3309 3310 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) { 3311 bool result = false; 3312 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE, 3313 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, 3314 -1, 0); 3315 3316 if (p != MAP_FAILED) { 3317 // We don't know if this really is a huge page or not. 3318 FILE *fp = fopen("/proc/self/maps", "r"); 3319 if (fp) { 3320 while (!feof(fp)) { 3321 char chars[257]; 3322 long x = 0; 3323 if (fgets(chars, sizeof(chars), fp)) { 3324 if (sscanf(chars, "%lx-%*x", &x) == 1 3325 && x == (long)p) { 3326 if (strstr (chars, "hugepage")) { 3327 result = true; 3328 break; 3329 } 3330 } 3331 } 3332 } 3333 fclose(fp); 3334 } 3335 munmap(p, page_size); 3336 } 3337 3338 if (warn && !result) { 3339 warning("HugeTLBFS is not supported by the operating system."); 3340 } 3341 3342 return result; 3343 } 3344 3345 // Set the coredump_filter bits to include largepages in core dump (bit 6) 3346 // 3347 // From the coredump_filter documentation: 3348 // 3349 // - (bit 0) anonymous private memory 3350 // - (bit 1) anonymous shared memory 3351 // - (bit 2) file-backed private memory 3352 // - (bit 3) file-backed shared memory 3353 // - (bit 4) ELF header pages in file-backed private memory areas (it is 3354 // effective only if the bit 2 is cleared) 3355 // - (bit 5) hugetlb private memory 3356 // - (bit 6) hugetlb shared memory 3357 // - (bit 7) dax private memory 3358 // - (bit 8) dax shared memory 3359 // 3360 static void set_coredump_filter(bool largepages, bool dax_shared) { 3361 FILE *f; 3362 long cdm; 3363 bool filter_changed = false; 3364 3365 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { 3366 return; 3367 } 3368 3369 if (fscanf(f, "%lx", &cdm) != 1) { 3370 fclose(f); 3371 return; 3372 } 3373 3374 rewind(f); 3375 3376 if (largepages && (cdm & LARGEPAGES_BIT) == 0) { 3377 cdm |= LARGEPAGES_BIT; 3378 filter_changed = true; 3379 } 3380 if (dax_shared && (cdm & DAX_SHARED_BIT) == 0) { 3381 cdm |= DAX_SHARED_BIT; 3382 filter_changed = true; 3383 } 3384 if (filter_changed) { 3385 fprintf(f, "%#lx", cdm); 3386 } 3387 3388 fclose(f); 3389 } 3390 3391 // Large page support 3392 3393 static size_t _large_page_size = 0; 3394 3395 size_t os::Linux::find_large_page_size() { 3396 size_t large_page_size = 0; 3397 3398 // large_page_size on Linux is used to round up heap size. x86 uses either 3399 // 2M or 4M page, depending on whether PAE (Physical Address Extensions) 3400 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use 3401 // page as large as 256M. 3402 // 3403 // Here we try to figure out page size by parsing /proc/meminfo and looking 3404 // for a line with the following format: 3405 // Hugepagesize: 2048 kB 3406 // 3407 // If we can't determine the value (e.g. /proc is not mounted, or the text 3408 // format has been changed), we'll use the largest page size supported by 3409 // the processor. 3410 3411 #ifndef ZERO 3412 large_page_size = 3413 AARCH64_ONLY(2 * M) 3414 AMD64_ONLY(2 * M) 3415 ARM32_ONLY(2 * M) 3416 IA32_ONLY(4 * M) 3417 IA64_ONLY(256 * M) 3418 PPC_ONLY(4 * M) 3419 S390_ONLY(1 * M) 3420 SPARC_ONLY(4 * M); 3421 #endif // ZERO 3422 3423 FILE *fp = fopen("/proc/meminfo", "r"); 3424 if (fp) { 3425 while (!feof(fp)) { 3426 int x = 0; 3427 char buf[16]; 3428 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { 3429 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { 3430 large_page_size = x * K; 3431 break; 3432 } 3433 } else { 3434 // skip to next line 3435 for (;;) { 3436 int ch = fgetc(fp); 3437 if (ch == EOF || ch == (int)'\n') break; 3438 } 3439 } 3440 } 3441 fclose(fp); 3442 } 3443 3444 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) { 3445 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is " 3446 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size), 3447 proper_unit_for_byte_size(large_page_size)); 3448 } 3449 3450 return large_page_size; 3451 } 3452 3453 size_t os::Linux::setup_large_page_size() { 3454 _large_page_size = Linux::find_large_page_size(); 3455 const size_t default_page_size = (size_t)Linux::page_size(); 3456 if (_large_page_size > default_page_size) { 3457 _page_sizes[0] = _large_page_size; 3458 _page_sizes[1] = default_page_size; 3459 _page_sizes[2] = 0; 3460 } 3461 3462 return _large_page_size; 3463 } 3464 3465 bool os::Linux::setup_large_page_type(size_t page_size) { 3466 if (FLAG_IS_DEFAULT(UseHugeTLBFS) && 3467 FLAG_IS_DEFAULT(UseSHM) && 3468 FLAG_IS_DEFAULT(UseTransparentHugePages)) { 3469 3470 // The type of large pages has not been specified by the user. 3471 3472 // Try UseHugeTLBFS and then UseSHM. 3473 UseHugeTLBFS = UseSHM = true; 3474 3475 // Don't try UseTransparentHugePages since there are known 3476 // performance issues with it turned on. This might change in the future. 3477 UseTransparentHugePages = false; 3478 } 3479 3480 if (UseTransparentHugePages) { 3481 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages); 3482 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) { 3483 UseHugeTLBFS = false; 3484 UseSHM = false; 3485 return true; 3486 } 3487 UseTransparentHugePages = false; 3488 } 3489 3490 if (UseHugeTLBFS) { 3491 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); 3492 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) { 3493 UseSHM = false; 3494 return true; 3495 } 3496 UseHugeTLBFS = false; 3497 } 3498 3499 return UseSHM; 3500 } 3501 3502 void os::large_page_init() { 3503 if (!UseLargePages && 3504 !UseTransparentHugePages && 3505 !UseHugeTLBFS && 3506 !UseSHM) { 3507 // Not using large pages. 3508 return; 3509 } 3510 3511 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) { 3512 // The user explicitly turned off large pages. 3513 // Ignore the rest of the large pages flags. 3514 UseTransparentHugePages = false; 3515 UseHugeTLBFS = false; 3516 UseSHM = false; 3517 return; 3518 } 3519 3520 size_t large_page_size = Linux::setup_large_page_size(); 3521 UseLargePages = Linux::setup_large_page_type(large_page_size); 3522 3523 set_coredump_filter(true /*largepages*/, false /*dax_shared*/); 3524 } 3525 3526 #ifndef SHM_HUGETLB 3527 #define SHM_HUGETLB 04000 3528 #endif 3529 3530 #define shm_warning_format(format, ...) \ 3531 do { \ 3532 if (UseLargePages && \ 3533 (!FLAG_IS_DEFAULT(UseLargePages) || \ 3534 !FLAG_IS_DEFAULT(UseSHM) || \ 3535 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \ 3536 warning(format, __VA_ARGS__); \ 3537 } \ 3538 } while (0) 3539 3540 #define shm_warning(str) shm_warning_format("%s", str) 3541 3542 #define shm_warning_with_errno(str) \ 3543 do { \ 3544 int err = errno; \ 3545 shm_warning_format(str " (error = %d)", err); \ 3546 } while (0) 3547 3548 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) { 3549 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment"); 3550 3551 if (!is_aligned(alignment, SHMLBA)) { 3552 assert(false, "Code below assumes that alignment is at least SHMLBA aligned"); 3553 return NULL; 3554 } 3555 3556 // To ensure that we get 'alignment' aligned memory from shmat, 3557 // we pre-reserve aligned virtual memory and then attach to that. 3558 3559 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL); 3560 if (pre_reserved_addr == NULL) { 3561 // Couldn't pre-reserve aligned memory. 3562 shm_warning("Failed to pre-reserve aligned memory for shmat."); 3563 return NULL; 3564 } 3565 3566 // SHM_REMAP is needed to allow shmat to map over an existing mapping. 3567 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP); 3568 3569 if ((intptr_t)addr == -1) { 3570 int err = errno; 3571 shm_warning_with_errno("Failed to attach shared memory."); 3572 3573 assert(err != EACCES, "Unexpected error"); 3574 assert(err != EIDRM, "Unexpected error"); 3575 assert(err != EINVAL, "Unexpected error"); 3576 3577 // Since we don't know if the kernel unmapped the pre-reserved memory area 3578 // we can't unmap it, since that would potentially unmap memory that was 3579 // mapped from other threads. 3580 return NULL; 3581 } 3582 3583 return addr; 3584 } 3585 3586 static char* shmat_at_address(int shmid, char* req_addr) { 3587 if (!is_aligned(req_addr, SHMLBA)) { 3588 assert(false, "Requested address needs to be SHMLBA aligned"); 3589 return NULL; 3590 } 3591 3592 char* addr = (char*)shmat(shmid, req_addr, 0); 3593 3594 if ((intptr_t)addr == -1) { 3595 shm_warning_with_errno("Failed to attach shared memory."); 3596 return NULL; 3597 } 3598 3599 return addr; 3600 } 3601 3602 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) { 3603 // If a req_addr has been provided, we assume that the caller has already aligned the address. 3604 if (req_addr != NULL) { 3605 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size"); 3606 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment"); 3607 return shmat_at_address(shmid, req_addr); 3608 } 3609 3610 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically 3611 // return large page size aligned memory addresses when req_addr == NULL. 3612 // However, if the alignment is larger than the large page size, we have 3613 // to manually ensure that the memory returned is 'alignment' aligned. 3614 if (alignment > os::large_page_size()) { 3615 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size"); 3616 return shmat_with_alignment(shmid, bytes, alignment); 3617 } else { 3618 return shmat_at_address(shmid, NULL); 3619 } 3620 } 3621 3622 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment, 3623 char* req_addr, bool exec) { 3624 // "exec" is passed in but not used. Creating the shared image for 3625 // the code cache doesn't have an SHM_X executable permission to check. 3626 assert(UseLargePages && UseSHM, "only for SHM large pages"); 3627 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3628 assert(is_aligned(req_addr, alignment), "Unaligned address"); 3629 3630 if (!is_aligned(bytes, os::large_page_size())) { 3631 return NULL; // Fallback to small pages. 3632 } 3633 3634 // Create a large shared memory region to attach to based on size. 3635 // Currently, size is the total size of the heap. 3636 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); 3637 if (shmid == -1) { 3638 // Possible reasons for shmget failure: 3639 // 1. shmmax is too small for Java heap. 3640 // > check shmmax value: cat /proc/sys/kernel/shmmax 3641 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 3642 // 2. not enough large page memory. 3643 // > check available large pages: cat /proc/meminfo 3644 // > increase amount of large pages: 3645 // echo new_value > /proc/sys/vm/nr_hugepages 3646 // Note 1: different Linux may use different name for this property, 3647 // e.g. on Redhat AS-3 it is "hugetlb_pool". 3648 // Note 2: it's possible there's enough physical memory available but 3649 // they are so fragmented after a long run that they can't 3650 // coalesce into large pages. Try to reserve large pages when 3651 // the system is still "fresh". 3652 shm_warning_with_errno("Failed to reserve shared memory."); 3653 return NULL; 3654 } 3655 3656 // Attach to the region. 3657 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr); 3658 3659 // Remove shmid. If shmat() is successful, the actual shared memory segment 3660 // will be deleted when it's detached by shmdt() or when the process 3661 // terminates. If shmat() is not successful this will remove the shared 3662 // segment immediately. 3663 shmctl(shmid, IPC_RMID, NULL); 3664 3665 return addr; 3666 } 3667 3668 static void warn_on_large_pages_failure(char* req_addr, size_t bytes, 3669 int error) { 3670 assert(error == ENOMEM, "Only expect to fail if no memory is available"); 3671 3672 bool warn_on_failure = UseLargePages && 3673 (!FLAG_IS_DEFAULT(UseLargePages) || 3674 !FLAG_IS_DEFAULT(UseHugeTLBFS) || 3675 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 3676 3677 if (warn_on_failure) { 3678 char msg[128]; 3679 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: " 3680 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error); 3681 warning("%s", msg); 3682 } 3683 } 3684 3685 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes, 3686 char* req_addr, 3687 bool exec) { 3688 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3689 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size"); 3690 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3691 3692 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3693 char* addr = (char*)::mmap(req_addr, bytes, prot, 3694 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, 3695 -1, 0); 3696 3697 if (addr == MAP_FAILED) { 3698 warn_on_large_pages_failure(req_addr, bytes, errno); 3699 return NULL; 3700 } 3701 3702 assert(is_aligned(addr, os::large_page_size()), "Must be"); 3703 3704 return addr; 3705 } 3706 3707 // Reserve memory using mmap(MAP_HUGETLB). 3708 // - bytes shall be a multiple of alignment. 3709 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3710 // - alignment sets the alignment at which memory shall be allocated. 3711 // It must be a multiple of allocation granularity. 3712 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3713 // req_addr or NULL. 3714 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes, 3715 size_t alignment, 3716 char* req_addr, 3717 bool exec) { 3718 size_t large_page_size = os::large_page_size(); 3719 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes"); 3720 3721 assert(is_aligned(req_addr, alignment), "Must be"); 3722 assert(is_aligned(bytes, alignment), "Must be"); 3723 3724 // First reserve - but not commit - the address range in small pages. 3725 char* const start = anon_mmap_aligned(bytes, alignment, req_addr); 3726 3727 if (start == NULL) { 3728 return NULL; 3729 } 3730 3731 assert(is_aligned(start, alignment), "Must be"); 3732 3733 char* end = start + bytes; 3734 3735 // Find the regions of the allocated chunk that can be promoted to large pages. 3736 char* lp_start = align_up(start, large_page_size); 3737 char* lp_end = align_down(end, large_page_size); 3738 3739 size_t lp_bytes = lp_end - lp_start; 3740 3741 assert(is_aligned(lp_bytes, large_page_size), "Must be"); 3742 3743 if (lp_bytes == 0) { 3744 // The mapped region doesn't even span the start and the end of a large page. 3745 // Fall back to allocate a non-special area. 3746 ::munmap(start, end - start); 3747 return NULL; 3748 } 3749 3750 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3751 3752 void* result; 3753 3754 // Commit small-paged leading area. 3755 if (start != lp_start) { 3756 result = ::mmap(start, lp_start - start, prot, 3757 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3758 -1, 0); 3759 if (result == MAP_FAILED) { 3760 ::munmap(lp_start, end - lp_start); 3761 return NULL; 3762 } 3763 } 3764 3765 // Commit large-paged area. 3766 result = ::mmap(lp_start, lp_bytes, prot, 3767 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB, 3768 -1, 0); 3769 if (result == MAP_FAILED) { 3770 warn_on_large_pages_failure(lp_start, lp_bytes, errno); 3771 // If the mmap above fails, the large pages region will be unmapped and we 3772 // have regions before and after with small pages. Release these regions. 3773 // 3774 // | mapped | unmapped | mapped | 3775 // ^ ^ ^ ^ 3776 // start lp_start lp_end end 3777 // 3778 ::munmap(start, lp_start - start); 3779 ::munmap(lp_end, end - lp_end); 3780 return NULL; 3781 } 3782 3783 // Commit small-paged trailing area. 3784 if (lp_end != end) { 3785 result = ::mmap(lp_end, end - lp_end, prot, 3786 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3787 -1, 0); 3788 if (result == MAP_FAILED) { 3789 ::munmap(start, lp_end - start); 3790 return NULL; 3791 } 3792 } 3793 3794 return start; 3795 } 3796 3797 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes, 3798 size_t alignment, 3799 char* req_addr, 3800 bool exec) { 3801 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3802 assert(is_aligned(req_addr, alignment), "Must be"); 3803 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be"); 3804 assert(is_power_of_2(os::large_page_size()), "Must be"); 3805 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes"); 3806 3807 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) { 3808 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec); 3809 } else { 3810 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec); 3811 } 3812 } 3813 3814 char* os::reserve_memory_special(size_t bytes, size_t alignment, 3815 char* req_addr, bool exec) { 3816 assert(UseLargePages, "only for large pages"); 3817 3818 char* addr; 3819 if (UseSHM) { 3820 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec); 3821 } else { 3822 assert(UseHugeTLBFS, "must be"); 3823 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec); 3824 } 3825 3826 if (addr != NULL) { 3827 if (UseNUMAInterleaving) { 3828 numa_make_global(addr, bytes); 3829 } 3830 3831 // The memory is committed 3832 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 3833 } 3834 3835 return addr; 3836 } 3837 3838 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) { 3839 // detaching the SHM segment will also delete it, see reserve_memory_special_shm() 3840 return shmdt(base) == 0; 3841 } 3842 3843 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) { 3844 return pd_release_memory(base, bytes); 3845 } 3846 3847 bool os::release_memory_special(char* base, size_t bytes) { 3848 bool res; 3849 if (MemTracker::tracking_level() > NMT_minimal) { 3850 Tracker tkr(Tracker::release); 3851 res = os::Linux::release_memory_special_impl(base, bytes); 3852 if (res) { 3853 tkr.record((address)base, bytes); 3854 } 3855 3856 } else { 3857 res = os::Linux::release_memory_special_impl(base, bytes); 3858 } 3859 return res; 3860 } 3861 3862 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) { 3863 assert(UseLargePages, "only for large pages"); 3864 bool res; 3865 3866 if (UseSHM) { 3867 res = os::Linux::release_memory_special_shm(base, bytes); 3868 } else { 3869 assert(UseHugeTLBFS, "must be"); 3870 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes); 3871 } 3872 return res; 3873 } 3874 3875 size_t os::large_page_size() { 3876 return _large_page_size; 3877 } 3878 3879 // With SysV SHM the entire memory region must be allocated as shared 3880 // memory. 3881 // HugeTLBFS allows application to commit large page memory on demand. 3882 // However, when committing memory with HugeTLBFS fails, the region 3883 // that was supposed to be committed will lose the old reservation 3884 // and allow other threads to steal that memory region. Because of this 3885 // behavior we can't commit HugeTLBFS memory. 3886 bool os::can_commit_large_page_memory() { 3887 return UseTransparentHugePages; 3888 } 3889 3890 bool os::can_execute_large_page_memory() { 3891 return UseTransparentHugePages || UseHugeTLBFS; 3892 } 3893 3894 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) { 3895 assert(file_desc >= 0, "file_desc is not valid"); 3896 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr); 3897 if (result != NULL) { 3898 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) { 3899 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory")); 3900 } 3901 } 3902 return result; 3903 } 3904 3905 // Reserve memory at an arbitrary address, only if that area is 3906 // available (and not reserved for something else). 3907 3908 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 3909 const int max_tries = 10; 3910 char* base[max_tries]; 3911 size_t size[max_tries]; 3912 const size_t gap = 0x000000; 3913 3914 // Assert only that the size is a multiple of the page size, since 3915 // that's all that mmap requires, and since that's all we really know 3916 // about at this low abstraction level. If we need higher alignment, 3917 // we can either pass an alignment to this method or verify alignment 3918 // in one of the methods further up the call chain. See bug 5044738. 3919 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 3920 3921 // Repeatedly allocate blocks until the block is allocated at the 3922 // right spot. 3923 3924 // Linux mmap allows caller to pass an address as hint; give it a try first, 3925 // if kernel honors the hint then we can return immediately. 3926 char * addr = anon_mmap(requested_addr, bytes, false); 3927 if (addr == requested_addr) { 3928 return requested_addr; 3929 } 3930 3931 if (addr != NULL) { 3932 // mmap() is successful but it fails to reserve at the requested address 3933 anon_munmap(addr, bytes); 3934 } 3935 3936 int i; 3937 for (i = 0; i < max_tries; ++i) { 3938 base[i] = reserve_memory(bytes); 3939 3940 if (base[i] != NULL) { 3941 // Is this the block we wanted? 3942 if (base[i] == requested_addr) { 3943 size[i] = bytes; 3944 break; 3945 } 3946 3947 // Does this overlap the block we wanted? Give back the overlapped 3948 // parts and try again. 3949 3950 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i]; 3951 if (top_overlap >= 0 && (size_t)top_overlap < bytes) { 3952 unmap_memory(base[i], top_overlap); 3953 base[i] += top_overlap; 3954 size[i] = bytes - top_overlap; 3955 } else { 3956 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr; 3957 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) { 3958 unmap_memory(requested_addr, bottom_overlap); 3959 size[i] = bytes - bottom_overlap; 3960 } else { 3961 size[i] = bytes; 3962 } 3963 } 3964 } 3965 } 3966 3967 // Give back the unused reserved pieces. 3968 3969 for (int j = 0; j < i; ++j) { 3970 if (base[j] != NULL) { 3971 unmap_memory(base[j], size[j]); 3972 } 3973 } 3974 3975 if (i < max_tries) { 3976 return requested_addr; 3977 } else { 3978 return NULL; 3979 } 3980 } 3981 3982 size_t os::read(int fd, void *buf, unsigned int nBytes) { 3983 return ::read(fd, buf, nBytes); 3984 } 3985 3986 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 3987 return ::pread(fd, buf, nBytes, offset); 3988 } 3989 3990 // Short sleep, direct OS call. 3991 // 3992 // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee 3993 // sched_yield(2) will actually give up the CPU: 3994 // 3995 // * Alone on this pariticular CPU, keeps running. 3996 // * Before the introduction of "skip_buddy" with "compat_yield" disabled 3997 // (pre 2.6.39). 3998 // 3999 // So calling this with 0 is an alternative. 4000 // 4001 void os::naked_short_sleep(jlong ms) { 4002 struct timespec req; 4003 4004 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 4005 req.tv_sec = 0; 4006 if (ms > 0) { 4007 req.tv_nsec = (ms % 1000) * 1000000; 4008 } else { 4009 req.tv_nsec = 1; 4010 } 4011 4012 nanosleep(&req, NULL); 4013 4014 return; 4015 } 4016 4017 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 4018 void os::infinite_sleep() { 4019 while (true) { // sleep forever ... 4020 ::sleep(100); // ... 100 seconds at a time 4021 } 4022 } 4023 4024 // Used to convert frequent JVM_Yield() to nops 4025 bool os::dont_yield() { 4026 return DontYieldALot; 4027 } 4028 4029 void os::naked_yield() { 4030 sched_yield(); 4031 } 4032 4033 //////////////////////////////////////////////////////////////////////////////// 4034 // thread priority support 4035 4036 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER 4037 // only supports dynamic priority, static priority must be zero. For real-time 4038 // applications, Linux supports SCHED_RR which allows static priority (1-99). 4039 // However, for large multi-threaded applications, SCHED_RR is not only slower 4040 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 4041 // of 5 runs - Sep 2005). 4042 // 4043 // The following code actually changes the niceness of kernel-thread/LWP. It 4044 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 4045 // not the entire user process, and user level threads are 1:1 mapped to kernel 4046 // threads. It has always been the case, but could change in the future. For 4047 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 4048 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 4049 4050 int os::java_to_os_priority[CriticalPriority + 1] = { 4051 19, // 0 Entry should never be used 4052 4053 4, // 1 MinPriority 4054 3, // 2 4055 2, // 3 4056 4057 1, // 4 4058 0, // 5 NormPriority 4059 -1, // 6 4060 4061 -2, // 7 4062 -3, // 8 4063 -4, // 9 NearMaxPriority 4064 4065 -5, // 10 MaxPriority 4066 4067 -5 // 11 CriticalPriority 4068 }; 4069 4070 static int prio_init() { 4071 if (ThreadPriorityPolicy == 1) { 4072 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 4073 // if effective uid is not root. Perhaps, a more elegant way of doing 4074 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 4075 if (geteuid() != 0) { 4076 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 4077 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux"); 4078 } 4079 ThreadPriorityPolicy = 0; 4080 } 4081 } 4082 if (UseCriticalJavaThreadPriority) { 4083 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 4084 } 4085 return 0; 4086 } 4087 4088 OSReturn os::set_native_priority(Thread* thread, int newpri) { 4089 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 4090 4091 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 4092 return (ret == 0) ? OS_OK : OS_ERR; 4093 } 4094 4095 OSReturn os::get_native_priority(const Thread* const thread, 4096 int *priority_ptr) { 4097 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 4098 *priority_ptr = java_to_os_priority[NormPriority]; 4099 return OS_OK; 4100 } 4101 4102 errno = 0; 4103 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 4104 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 4105 } 4106 4107 // Hint to the underlying OS that a task switch would not be good. 4108 // Void return because it's a hint and can fail. 4109 void os::hint_no_preempt() {} 4110 4111 //////////////////////////////////////////////////////////////////////////////// 4112 // suspend/resume support 4113 4114 // The low-level signal-based suspend/resume support is a remnant from the 4115 // old VM-suspension that used to be for java-suspension, safepoints etc, 4116 // within hotspot. Currently used by JFR's OSThreadSampler 4117 // 4118 // The remaining code is greatly simplified from the more general suspension 4119 // code that used to be used. 4120 // 4121 // The protocol is quite simple: 4122 // - suspend: 4123 // - sends a signal to the target thread 4124 // - polls the suspend state of the osthread using a yield loop 4125 // - target thread signal handler (SR_handler) sets suspend state 4126 // and blocks in sigsuspend until continued 4127 // - resume: 4128 // - sets target osthread state to continue 4129 // - sends signal to end the sigsuspend loop in the SR_handler 4130 // 4131 // Note that the SR_lock plays no role in this suspend/resume protocol, 4132 // but is checked for NULL in SR_handler as a thread termination indicator. 4133 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs. 4134 // 4135 // Note that resume_clear_context() and suspend_save_context() are needed 4136 // by SR_handler(), so that fetch_frame_from_ucontext() works, 4137 // which in part is used by: 4138 // - Forte Analyzer: AsyncGetCallTrace() 4139 // - StackBanging: get_frame_at_stack_banging_point() 4140 4141 static void resume_clear_context(OSThread *osthread) { 4142 osthread->set_ucontext(NULL); 4143 osthread->set_siginfo(NULL); 4144 } 4145 4146 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, 4147 ucontext_t* context) { 4148 osthread->set_ucontext(context); 4149 osthread->set_siginfo(siginfo); 4150 } 4151 4152 // Handler function invoked when a thread's execution is suspended or 4153 // resumed. We have to be careful that only async-safe functions are 4154 // called here (Note: most pthread functions are not async safe and 4155 // should be avoided.) 4156 // 4157 // Note: sigwait() is a more natural fit than sigsuspend() from an 4158 // interface point of view, but sigwait() prevents the signal hander 4159 // from being run. libpthread would get very confused by not having 4160 // its signal handlers run and prevents sigwait()'s use with the 4161 // mutex granting granting signal. 4162 // 4163 // Currently only ever called on the VMThread and JavaThreads (PC sampling) 4164 // 4165 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 4166 // Save and restore errno to avoid confusing native code with EINTR 4167 // after sigsuspend. 4168 int old_errno = errno; 4169 4170 Thread* thread = Thread::current_or_null_safe(); 4171 assert(thread != NULL, "Missing current thread in SR_handler"); 4172 4173 // On some systems we have seen signal delivery get "stuck" until the signal 4174 // mask is changed as part of thread termination. Check that the current thread 4175 // has not already terminated (via SR_lock()) - else the following assertion 4176 // will fail because the thread is no longer a JavaThread as the ~JavaThread 4177 // destructor has completed. 4178 4179 if (thread->SR_lock() == NULL) { 4180 return; 4181 } 4182 4183 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 4184 4185 OSThread* osthread = thread->osthread(); 4186 4187 os::SuspendResume::State current = osthread->sr.state(); 4188 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 4189 suspend_save_context(osthread, siginfo, context); 4190 4191 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 4192 os::SuspendResume::State state = osthread->sr.suspended(); 4193 if (state == os::SuspendResume::SR_SUSPENDED) { 4194 sigset_t suspend_set; // signals for sigsuspend() 4195 sigemptyset(&suspend_set); 4196 // get current set of blocked signals and unblock resume signal 4197 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 4198 sigdelset(&suspend_set, SR_signum); 4199 4200 sr_semaphore.signal(); 4201 // wait here until we are resumed 4202 while (1) { 4203 sigsuspend(&suspend_set); 4204 4205 os::SuspendResume::State result = osthread->sr.running(); 4206 if (result == os::SuspendResume::SR_RUNNING) { 4207 sr_semaphore.signal(); 4208 break; 4209 } 4210 } 4211 4212 } else if (state == os::SuspendResume::SR_RUNNING) { 4213 // request was cancelled, continue 4214 } else { 4215 ShouldNotReachHere(); 4216 } 4217 4218 resume_clear_context(osthread); 4219 } else if (current == os::SuspendResume::SR_RUNNING) { 4220 // request was cancelled, continue 4221 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 4222 // ignore 4223 } else { 4224 // ignore 4225 } 4226 4227 errno = old_errno; 4228 } 4229 4230 static int SR_initialize() { 4231 struct sigaction act; 4232 char *s; 4233 4234 // Get signal number to use for suspend/resume 4235 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 4236 int sig = ::strtol(s, 0, 10); 4237 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769. 4238 sig < NSIG) { // Must be legal signal and fit into sigflags[]. 4239 SR_signum = sig; 4240 } else { 4241 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.", 4242 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum); 4243 } 4244 } 4245 4246 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 4247 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 4248 4249 sigemptyset(&SR_sigset); 4250 sigaddset(&SR_sigset, SR_signum); 4251 4252 // Set up signal handler for suspend/resume 4253 act.sa_flags = SA_RESTART|SA_SIGINFO; 4254 act.sa_handler = (void (*)(int)) SR_handler; 4255 4256 // SR_signum is blocked by default. 4257 // 4528190 - We also need to block pthread restart signal (32 on all 4258 // supported Linux platforms). Note that LinuxThreads need to block 4259 // this signal for all threads to work properly. So we don't have 4260 // to use hard-coded signal number when setting up the mask. 4261 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 4262 4263 if (sigaction(SR_signum, &act, 0) == -1) { 4264 return -1; 4265 } 4266 4267 // Save signal flag 4268 os::Linux::set_our_sigflags(SR_signum, act.sa_flags); 4269 return 0; 4270 } 4271 4272 static int sr_notify(OSThread* osthread) { 4273 int status = pthread_kill(osthread->pthread_id(), SR_signum); 4274 assert_status(status == 0, status, "pthread_kill"); 4275 return status; 4276 } 4277 4278 // "Randomly" selected value for how long we want to spin 4279 // before bailing out on suspending a thread, also how often 4280 // we send a signal to a thread we want to resume 4281 static const int RANDOMLY_LARGE_INTEGER = 1000000; 4282 static const int RANDOMLY_LARGE_INTEGER2 = 100; 4283 4284 // returns true on success and false on error - really an error is fatal 4285 // but this seems the normal response to library errors 4286 static bool do_suspend(OSThread* osthread) { 4287 assert(osthread->sr.is_running(), "thread should be running"); 4288 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 4289 4290 // mark as suspended and send signal 4291 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 4292 // failed to switch, state wasn't running? 4293 ShouldNotReachHere(); 4294 return false; 4295 } 4296 4297 if (sr_notify(osthread) != 0) { 4298 ShouldNotReachHere(); 4299 } 4300 4301 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 4302 while (true) { 4303 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { 4304 break; 4305 } else { 4306 // timeout 4307 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 4308 if (cancelled == os::SuspendResume::SR_RUNNING) { 4309 return false; 4310 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 4311 // make sure that we consume the signal on the semaphore as well 4312 sr_semaphore.wait(); 4313 break; 4314 } else { 4315 ShouldNotReachHere(); 4316 return false; 4317 } 4318 } 4319 } 4320 4321 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 4322 return true; 4323 } 4324 4325 static void do_resume(OSThread* osthread) { 4326 assert(osthread->sr.is_suspended(), "thread should be suspended"); 4327 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 4328 4329 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 4330 // failed to switch to WAKEUP_REQUEST 4331 ShouldNotReachHere(); 4332 return; 4333 } 4334 4335 while (true) { 4336 if (sr_notify(osthread) == 0) { 4337 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { 4338 if (osthread->sr.is_running()) { 4339 return; 4340 } 4341 } 4342 } else { 4343 ShouldNotReachHere(); 4344 } 4345 } 4346 4347 guarantee(osthread->sr.is_running(), "Must be running!"); 4348 } 4349 4350 /////////////////////////////////////////////////////////////////////////////////// 4351 // signal handling (except suspend/resume) 4352 4353 // This routine may be used by user applications as a "hook" to catch signals. 4354 // The user-defined signal handler must pass unrecognized signals to this 4355 // routine, and if it returns true (non-zero), then the signal handler must 4356 // return immediately. If the flag "abort_if_unrecognized" is true, then this 4357 // routine will never retun false (zero), but instead will execute a VM panic 4358 // routine kill the process. 4359 // 4360 // If this routine returns false, it is OK to call it again. This allows 4361 // the user-defined signal handler to perform checks either before or after 4362 // the VM performs its own checks. Naturally, the user code would be making 4363 // a serious error if it tried to handle an exception (such as a null check 4364 // or breakpoint) that the VM was generating for its own correct operation. 4365 // 4366 // This routine may recognize any of the following kinds of signals: 4367 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 4368 // It should be consulted by handlers for any of those signals. 4369 // 4370 // The caller of this routine must pass in the three arguments supplied 4371 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 4372 // field of the structure passed to sigaction(). This routine assumes that 4373 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 4374 // 4375 // Note that the VM will print warnings if it detects conflicting signal 4376 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 4377 // 4378 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo, 4379 siginfo_t* siginfo, 4380 void* ucontext, 4381 int abort_if_unrecognized); 4382 4383 void signalHandler(int sig, siginfo_t* info, void* uc) { 4384 assert(info != NULL && uc != NULL, "it must be old kernel"); 4385 int orig_errno = errno; // Preserve errno value over signal handler. 4386 JVM_handle_linux_signal(sig, info, uc, true); 4387 errno = orig_errno; 4388 } 4389 4390 4391 // This boolean allows users to forward their own non-matching signals 4392 // to JVM_handle_linux_signal, harmlessly. 4393 bool os::Linux::signal_handlers_are_installed = false; 4394 4395 // For signal-chaining 4396 struct sigaction sigact[NSIG]; 4397 uint64_t sigs = 0; 4398 #if (64 < NSIG-1) 4399 #error "Not all signals can be encoded in sigs. Adapt its type!" 4400 #endif 4401 bool os::Linux::libjsig_is_loaded = false; 4402 typedef struct sigaction *(*get_signal_t)(int); 4403 get_signal_t os::Linux::get_signal_action = NULL; 4404 4405 struct sigaction* os::Linux::get_chained_signal_action(int sig) { 4406 struct sigaction *actp = NULL; 4407 4408 if (libjsig_is_loaded) { 4409 // Retrieve the old signal handler from libjsig 4410 actp = (*get_signal_action)(sig); 4411 } 4412 if (actp == NULL) { 4413 // Retrieve the preinstalled signal handler from jvm 4414 actp = get_preinstalled_handler(sig); 4415 } 4416 4417 return actp; 4418 } 4419 4420 static bool call_chained_handler(struct sigaction *actp, int sig, 4421 siginfo_t *siginfo, void *context) { 4422 // Call the old signal handler 4423 if (actp->sa_handler == SIG_DFL) { 4424 // It's more reasonable to let jvm treat it as an unexpected exception 4425 // instead of taking the default action. 4426 return false; 4427 } else if (actp->sa_handler != SIG_IGN) { 4428 if ((actp->sa_flags & SA_NODEFER) == 0) { 4429 // automaticlly block the signal 4430 sigaddset(&(actp->sa_mask), sig); 4431 } 4432 4433 sa_handler_t hand = NULL; 4434 sa_sigaction_t sa = NULL; 4435 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 4436 // retrieve the chained handler 4437 if (siginfo_flag_set) { 4438 sa = actp->sa_sigaction; 4439 } else { 4440 hand = actp->sa_handler; 4441 } 4442 4443 if ((actp->sa_flags & SA_RESETHAND) != 0) { 4444 actp->sa_handler = SIG_DFL; 4445 } 4446 4447 // try to honor the signal mask 4448 sigset_t oset; 4449 sigemptyset(&oset); 4450 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 4451 4452 // call into the chained handler 4453 if (siginfo_flag_set) { 4454 (*sa)(sig, siginfo, context); 4455 } else { 4456 (*hand)(sig); 4457 } 4458 4459 // restore the signal mask 4460 pthread_sigmask(SIG_SETMASK, &oset, NULL); 4461 } 4462 // Tell jvm's signal handler the signal is taken care of. 4463 return true; 4464 } 4465 4466 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) { 4467 bool chained = false; 4468 // signal-chaining 4469 if (UseSignalChaining) { 4470 struct sigaction *actp = get_chained_signal_action(sig); 4471 if (actp != NULL) { 4472 chained = call_chained_handler(actp, sig, siginfo, context); 4473 } 4474 } 4475 return chained; 4476 } 4477 4478 struct sigaction* os::Linux::get_preinstalled_handler(int sig) { 4479 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) { 4480 return &sigact[sig]; 4481 } 4482 return NULL; 4483 } 4484 4485 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 4486 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4487 sigact[sig] = oldAct; 4488 sigs |= (uint64_t)1 << (sig-1); 4489 } 4490 4491 // for diagnostic 4492 int sigflags[NSIG]; 4493 4494 int os::Linux::get_our_sigflags(int sig) { 4495 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4496 return sigflags[sig]; 4497 } 4498 4499 void os::Linux::set_our_sigflags(int sig, int flags) { 4500 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4501 if (sig > 0 && sig < NSIG) { 4502 sigflags[sig] = flags; 4503 } 4504 } 4505 4506 void os::Linux::set_signal_handler(int sig, bool set_installed) { 4507 // Check for overwrite. 4508 struct sigaction oldAct; 4509 sigaction(sig, (struct sigaction*)NULL, &oldAct); 4510 4511 void* oldhand = oldAct.sa_sigaction 4512 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4513 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4514 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 4515 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 4516 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 4517 if (AllowUserSignalHandlers || !set_installed) { 4518 // Do not overwrite; user takes responsibility to forward to us. 4519 return; 4520 } else if (UseSignalChaining) { 4521 // save the old handler in jvm 4522 save_preinstalled_handler(sig, oldAct); 4523 // libjsig also interposes the sigaction() call below and saves the 4524 // old sigaction on it own. 4525 } else { 4526 fatal("Encountered unexpected pre-existing sigaction handler " 4527 "%#lx for signal %d.", (long)oldhand, sig); 4528 } 4529 } 4530 4531 struct sigaction sigAct; 4532 sigfillset(&(sigAct.sa_mask)); 4533 sigAct.sa_handler = SIG_DFL; 4534 if (!set_installed) { 4535 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4536 } else { 4537 sigAct.sa_sigaction = signalHandler; 4538 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4539 } 4540 // Save flags, which are set by ours 4541 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4542 sigflags[sig] = sigAct.sa_flags; 4543 4544 int ret = sigaction(sig, &sigAct, &oldAct); 4545 assert(ret == 0, "check"); 4546 4547 void* oldhand2 = oldAct.sa_sigaction 4548 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4549 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4550 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 4551 } 4552 4553 // install signal handlers for signals that HotSpot needs to 4554 // handle in order to support Java-level exception handling. 4555 4556 void os::Linux::install_signal_handlers() { 4557 if (!signal_handlers_are_installed) { 4558 signal_handlers_are_installed = true; 4559 4560 // signal-chaining 4561 typedef void (*signal_setting_t)(); 4562 signal_setting_t begin_signal_setting = NULL; 4563 signal_setting_t end_signal_setting = NULL; 4564 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4565 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 4566 if (begin_signal_setting != NULL) { 4567 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4568 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 4569 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 4570 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 4571 libjsig_is_loaded = true; 4572 assert(UseSignalChaining, "should enable signal-chaining"); 4573 } 4574 if (libjsig_is_loaded) { 4575 // Tell libjsig jvm is setting signal handlers 4576 (*begin_signal_setting)(); 4577 } 4578 4579 set_signal_handler(SIGSEGV, true); 4580 set_signal_handler(SIGPIPE, true); 4581 set_signal_handler(SIGBUS, true); 4582 set_signal_handler(SIGILL, true); 4583 set_signal_handler(SIGFPE, true); 4584 #if defined(PPC64) 4585 set_signal_handler(SIGTRAP, true); 4586 #endif 4587 set_signal_handler(SIGXFSZ, true); 4588 4589 if (libjsig_is_loaded) { 4590 // Tell libjsig jvm finishes setting signal handlers 4591 (*end_signal_setting)(); 4592 } 4593 4594 // We don't activate signal checker if libjsig is in place, we trust ourselves 4595 // and if UserSignalHandler is installed all bets are off. 4596 // Log that signal checking is off only if -verbose:jni is specified. 4597 if (CheckJNICalls) { 4598 if (libjsig_is_loaded) { 4599 if (PrintJNIResolving) { 4600 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 4601 } 4602 check_signals = false; 4603 } 4604 if (AllowUserSignalHandlers) { 4605 if (PrintJNIResolving) { 4606 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 4607 } 4608 check_signals = false; 4609 } 4610 } 4611 } 4612 } 4613 4614 // This is the fastest way to get thread cpu time on Linux. 4615 // Returns cpu time (user+sys) for any thread, not only for current. 4616 // POSIX compliant clocks are implemented in the kernels 2.6.16+. 4617 // It might work on 2.6.10+ with a special kernel/glibc patch. 4618 // For reference, please, see IEEE Std 1003.1-2004: 4619 // http://www.unix.org/single_unix_specification 4620 4621 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) { 4622 struct timespec tp; 4623 int rc = os::Linux::clock_gettime(clockid, &tp); 4624 assert(rc == 0, "clock_gettime is expected to return 0 code"); 4625 4626 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec; 4627 } 4628 4629 void os::Linux::initialize_os_info() { 4630 assert(_os_version == 0, "OS info already initialized"); 4631 4632 struct utsname _uname; 4633 4634 uint32_t major; 4635 uint32_t minor; 4636 uint32_t fix; 4637 4638 int rc; 4639 4640 // Kernel version is unknown if 4641 // verification below fails. 4642 _os_version = 0x01000000; 4643 4644 rc = uname(&_uname); 4645 if (rc != -1) { 4646 4647 rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix); 4648 if (rc == 3) { 4649 4650 if (major < 256 && minor < 256 && fix < 256) { 4651 // Kernel version format is as expected, 4652 // set it overriding unknown state. 4653 _os_version = (major << 16) | 4654 (minor << 8 ) | 4655 (fix << 0 ) ; 4656 } 4657 } 4658 } 4659 } 4660 4661 uint32_t os::Linux::os_version() { 4662 assert(_os_version != 0, "not initialized"); 4663 return _os_version & 0x00FFFFFF; 4664 } 4665 4666 bool os::Linux::os_version_is_known() { 4667 assert(_os_version != 0, "not initialized"); 4668 return _os_version & 0x01000000 ? false : true; 4669 } 4670 4671 ///// 4672 // glibc on Linux platform uses non-documented flag 4673 // to indicate, that some special sort of signal 4674 // trampoline is used. 4675 // We will never set this flag, and we should 4676 // ignore this flag in our diagnostic 4677 #ifdef SIGNIFICANT_SIGNAL_MASK 4678 #undef SIGNIFICANT_SIGNAL_MASK 4679 #endif 4680 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 4681 4682 static const char* get_signal_handler_name(address handler, 4683 char* buf, int buflen) { 4684 int offset = 0; 4685 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 4686 if (found) { 4687 // skip directory names 4688 const char *p1, *p2; 4689 p1 = buf; 4690 size_t len = strlen(os::file_separator()); 4691 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 4692 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 4693 } else { 4694 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 4695 } 4696 return buf; 4697 } 4698 4699 static void print_signal_handler(outputStream* st, int sig, 4700 char* buf, size_t buflen) { 4701 struct sigaction sa; 4702 4703 sigaction(sig, NULL, &sa); 4704 4705 // See comment for SIGNIFICANT_SIGNAL_MASK define 4706 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4707 4708 st->print("%s: ", os::exception_name(sig, buf, buflen)); 4709 4710 address handler = (sa.sa_flags & SA_SIGINFO) 4711 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 4712 : CAST_FROM_FN_PTR(address, sa.sa_handler); 4713 4714 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 4715 st->print("SIG_DFL"); 4716 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 4717 st->print("SIG_IGN"); 4718 } else { 4719 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 4720 } 4721 4722 st->print(", sa_mask[0]="); 4723 os::Posix::print_signal_set_short(st, &sa.sa_mask); 4724 4725 address rh = VMError::get_resetted_sighandler(sig); 4726 // May be, handler was resetted by VMError? 4727 if (rh != NULL) { 4728 handler = rh; 4729 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 4730 } 4731 4732 st->print(", sa_flags="); 4733 os::Posix::print_sa_flags(st, sa.sa_flags); 4734 4735 // Check: is it our handler? 4736 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 4737 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 4738 // It is our signal handler 4739 // check for flags, reset system-used one! 4740 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) { 4741 st->print( 4742 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 4743 os::Linux::get_our_sigflags(sig)); 4744 } 4745 } 4746 st->cr(); 4747 } 4748 4749 4750 #define DO_SIGNAL_CHECK(sig) \ 4751 do { \ 4752 if (!sigismember(&check_signal_done, sig)) { \ 4753 os::Linux::check_signal_handler(sig); \ 4754 } \ 4755 } while (0) 4756 4757 // This method is a periodic task to check for misbehaving JNI applications 4758 // under CheckJNI, we can add any periodic checks here 4759 4760 void os::run_periodic_checks() { 4761 if (check_signals == false) return; 4762 4763 // SEGV and BUS if overridden could potentially prevent 4764 // generation of hs*.log in the event of a crash, debugging 4765 // such a case can be very challenging, so we absolutely 4766 // check the following for a good measure: 4767 DO_SIGNAL_CHECK(SIGSEGV); 4768 DO_SIGNAL_CHECK(SIGILL); 4769 DO_SIGNAL_CHECK(SIGFPE); 4770 DO_SIGNAL_CHECK(SIGBUS); 4771 DO_SIGNAL_CHECK(SIGPIPE); 4772 DO_SIGNAL_CHECK(SIGXFSZ); 4773 #if defined(PPC64) 4774 DO_SIGNAL_CHECK(SIGTRAP); 4775 #endif 4776 4777 // ReduceSignalUsage allows the user to override these handlers 4778 // see comments at the very top and jvm_md.h 4779 if (!ReduceSignalUsage) { 4780 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 4781 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 4782 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 4783 DO_SIGNAL_CHECK(BREAK_SIGNAL); 4784 } 4785 4786 DO_SIGNAL_CHECK(SR_signum); 4787 } 4788 4789 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 4790 4791 static os_sigaction_t os_sigaction = NULL; 4792 4793 void os::Linux::check_signal_handler(int sig) { 4794 char buf[O_BUFLEN]; 4795 address jvmHandler = NULL; 4796 4797 4798 struct sigaction act; 4799 if (os_sigaction == NULL) { 4800 // only trust the default sigaction, in case it has been interposed 4801 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 4802 if (os_sigaction == NULL) return; 4803 } 4804 4805 os_sigaction(sig, (struct sigaction*)NULL, &act); 4806 4807 4808 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4809 4810 address thisHandler = (act.sa_flags & SA_SIGINFO) 4811 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 4812 : CAST_FROM_FN_PTR(address, act.sa_handler); 4813 4814 4815 switch (sig) { 4816 case SIGSEGV: 4817 case SIGBUS: 4818 case SIGFPE: 4819 case SIGPIPE: 4820 case SIGILL: 4821 case SIGXFSZ: 4822 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 4823 break; 4824 4825 case SHUTDOWN1_SIGNAL: 4826 case SHUTDOWN2_SIGNAL: 4827 case SHUTDOWN3_SIGNAL: 4828 case BREAK_SIGNAL: 4829 jvmHandler = (address)user_handler(); 4830 break; 4831 4832 default: 4833 if (sig == SR_signum) { 4834 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 4835 } else { 4836 return; 4837 } 4838 break; 4839 } 4840 4841 if (thisHandler != jvmHandler) { 4842 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 4843 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 4844 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 4845 // No need to check this sig any longer 4846 sigaddset(&check_signal_done, sig); 4847 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 4848 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 4849 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 4850 exception_name(sig, buf, O_BUFLEN)); 4851 } 4852 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) { 4853 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 4854 tty->print("expected:"); 4855 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig)); 4856 tty->cr(); 4857 tty->print(" found:"); 4858 os::Posix::print_sa_flags(tty, act.sa_flags); 4859 tty->cr(); 4860 // No need to check this sig any longer 4861 sigaddset(&check_signal_done, sig); 4862 } 4863 4864 // Dump all the signal 4865 if (sigismember(&check_signal_done, sig)) { 4866 print_signal_handlers(tty, buf, O_BUFLEN); 4867 } 4868 } 4869 4870 extern void report_error(char* file_name, int line_no, char* title, 4871 char* format, ...); 4872 4873 // this is called _before_ most of the global arguments have been parsed 4874 void os::init(void) { 4875 char dummy; // used to get a guess on initial stack address 4876 4877 clock_tics_per_sec = sysconf(_SC_CLK_TCK); 4878 4879 init_random(1234567); 4880 4881 Linux::set_page_size(sysconf(_SC_PAGESIZE)); 4882 if (Linux::page_size() == -1) { 4883 fatal("os_linux.cpp: os::init: sysconf failed (%s)", 4884 os::strerror(errno)); 4885 } 4886 init_page_sizes((size_t) Linux::page_size()); 4887 4888 Linux::initialize_system_info(); 4889 4890 Linux::initialize_os_info(); 4891 4892 // _main_thread points to the thread that created/loaded the JVM. 4893 Linux::_main_thread = pthread_self(); 4894 4895 Linux::clock_init(); 4896 initial_time_count = javaTimeNanos(); 4897 4898 // retrieve entry point for pthread_setname_np 4899 Linux::_pthread_setname_np = 4900 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np"); 4901 4902 os::Posix::init(); 4903 } 4904 4905 // To install functions for atexit system call 4906 extern "C" { 4907 static void perfMemory_exit_helper() { 4908 perfMemory_exit(); 4909 } 4910 } 4911 4912 void os::pd_init_container_support() { 4913 OSContainer::init(); 4914 } 4915 4916 // this is called _after_ the global arguments have been parsed 4917 jint os::init_2(void) { 4918 4919 os::Posix::init_2(); 4920 4921 Linux::fast_thread_clock_init(); 4922 4923 // initialize suspend/resume support - must do this before signal_sets_init() 4924 if (SR_initialize() != 0) { 4925 perror("SR_initialize failed"); 4926 return JNI_ERR; 4927 } 4928 4929 Linux::signal_sets_init(); 4930 Linux::install_signal_handlers(); 4931 4932 // Check and sets minimum stack sizes against command line options 4933 if (Posix::set_minimum_stack_sizes() == JNI_ERR) { 4934 return JNI_ERR; 4935 } 4936 Linux::capture_initial_stack(JavaThread::stack_size_at_create()); 4937 4938 #if defined(IA32) 4939 workaround_expand_exec_shield_cs_limit(); 4940 #endif 4941 4942 Linux::libpthread_init(); 4943 Linux::sched_getcpu_init(); 4944 log_info(os)("HotSpot is running with %s, %s", 4945 Linux::glibc_version(), Linux::libpthread_version()); 4946 4947 if (UseNUMA) { 4948 if (!Linux::libnuma_init()) { 4949 UseNUMA = false; 4950 } else { 4951 if ((Linux::numa_max_node() < 1)) { 4952 // There's only one node(they start from 0), disable NUMA. 4953 UseNUMA = false; 4954 } 4955 } 4956 4957 if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) { 4958 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way 4959 // we can make the adaptive lgrp chunk resizing work. If the user specified both 4960 // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn 4961 // and disable adaptive resizing. 4962 if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) { 4963 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, " 4964 "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)"); 4965 UseAdaptiveSizePolicy = false; 4966 UseAdaptiveNUMAChunkSizing = false; 4967 } 4968 } 4969 4970 if (!UseNUMA && ForceNUMA) { 4971 UseNUMA = true; 4972 } 4973 } 4974 4975 if (MaxFDLimit) { 4976 // set the number of file descriptors to max. print out error 4977 // if getrlimit/setrlimit fails but continue regardless. 4978 struct rlimit nbr_files; 4979 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 4980 if (status != 0) { 4981 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno)); 4982 } else { 4983 nbr_files.rlim_cur = nbr_files.rlim_max; 4984 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 4985 if (status != 0) { 4986 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno)); 4987 } 4988 } 4989 } 4990 4991 // Initialize lock used to serialize thread creation (see os::create_thread) 4992 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); 4993 4994 // at-exit methods are called in the reverse order of their registration. 4995 // atexit functions are called on return from main or as a result of a 4996 // call to exit(3C). There can be only 32 of these functions registered 4997 // and atexit() does not set errno. 4998 4999 if (PerfAllowAtExitRegistration) { 5000 // only register atexit functions if PerfAllowAtExitRegistration is set. 5001 // atexit functions can be delayed until process exit time, which 5002 // can be problematic for embedded VM situations. Embedded VMs should 5003 // call DestroyJavaVM() to assure that VM resources are released. 5004 5005 // note: perfMemory_exit_helper atexit function may be removed in 5006 // the future if the appropriate cleanup code can be added to the 5007 // VM_Exit VMOperation's doit method. 5008 if (atexit(perfMemory_exit_helper) != 0) { 5009 warning("os::init_2 atexit(perfMemory_exit_helper) failed"); 5010 } 5011 } 5012 5013 // initialize thread priority policy 5014 prio_init(); 5015 5016 if (!FLAG_IS_DEFAULT(AllocateHeapAt)) { 5017 set_coredump_filter(false /*largepages*/, true /*dax_shared*/); 5018 } 5019 return JNI_OK; 5020 } 5021 5022 // Mark the polling page as unreadable 5023 void os::make_polling_page_unreadable(void) { 5024 if (!guard_memory((char*)_polling_page, Linux::page_size())) { 5025 fatal("Could not disable polling page"); 5026 } 5027 } 5028 5029 // Mark the polling page as readable 5030 void os::make_polling_page_readable(void) { 5031 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) { 5032 fatal("Could not enable polling page"); 5033 } 5034 } 5035 5036 // older glibc versions don't have this macro (which expands to 5037 // an optimized bit-counting function) so we have to roll our own 5038 #ifndef CPU_COUNT 5039 5040 static int _cpu_count(const cpu_set_t* cpus) { 5041 int count = 0; 5042 // only look up to the number of configured processors 5043 for (int i = 0; i < os::processor_count(); i++) { 5044 if (CPU_ISSET(i, cpus)) { 5045 count++; 5046 } 5047 } 5048 return count; 5049 } 5050 5051 #define CPU_COUNT(cpus) _cpu_count(cpus) 5052 5053 #endif // CPU_COUNT 5054 5055 // Get the current number of available processors for this process. 5056 // This value can change at any time during a process's lifetime. 5057 // sched_getaffinity gives an accurate answer as it accounts for cpusets. 5058 // If it appears there may be more than 1024 processors then we do a 5059 // dynamic check - see 6515172 for details. 5060 // If anything goes wrong we fallback to returning the number of online 5061 // processors - which can be greater than the number available to the process. 5062 int os::Linux::active_processor_count() { 5063 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors 5064 cpu_set_t* cpus_p = &cpus; 5065 int cpus_size = sizeof(cpu_set_t); 5066 5067 int configured_cpus = os::processor_count(); // upper bound on available cpus 5068 int cpu_count = 0; 5069 5070 // old build platforms may not support dynamic cpu sets 5071 #ifdef CPU_ALLOC 5072 5073 // To enable easy testing of the dynamic path on different platforms we 5074 // introduce a diagnostic flag: UseCpuAllocPath 5075 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) { 5076 // kernel may use a mask bigger than cpu_set_t 5077 log_trace(os)("active_processor_count: using dynamic path %s" 5078 "- configured processors: %d", 5079 UseCpuAllocPath ? "(forced) " : "", 5080 configured_cpus); 5081 cpus_p = CPU_ALLOC(configured_cpus); 5082 if (cpus_p != NULL) { 5083 cpus_size = CPU_ALLOC_SIZE(configured_cpus); 5084 // zero it just to be safe 5085 CPU_ZERO_S(cpus_size, cpus_p); 5086 } 5087 else { 5088 // failed to allocate so fallback to online cpus 5089 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); 5090 log_trace(os)("active_processor_count: " 5091 "CPU_ALLOC failed (%s) - using " 5092 "online processor count: %d", 5093 os::strerror(errno), online_cpus); 5094 return online_cpus; 5095 } 5096 } 5097 else { 5098 log_trace(os)("active_processor_count: using static path - configured processors: %d", 5099 configured_cpus); 5100 } 5101 #else // CPU_ALLOC 5102 // these stubs won't be executed 5103 #define CPU_COUNT_S(size, cpus) -1 5104 #define CPU_FREE(cpus) 5105 5106 log_trace(os)("active_processor_count: only static path available - configured processors: %d", 5107 configured_cpus); 5108 #endif // CPU_ALLOC 5109 5110 // pid 0 means the current thread - which we have to assume represents the process 5111 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) { 5112 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5113 cpu_count = CPU_COUNT_S(cpus_size, cpus_p); 5114 } 5115 else { 5116 cpu_count = CPU_COUNT(cpus_p); 5117 } 5118 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count); 5119 } 5120 else { 5121 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN); 5122 warning("sched_getaffinity failed (%s)- using online processor count (%d) " 5123 "which may exceed available processors", os::strerror(errno), cpu_count); 5124 } 5125 5126 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5127 CPU_FREE(cpus_p); 5128 } 5129 5130 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check"); 5131 return cpu_count; 5132 } 5133 5134 // Determine the active processor count from one of 5135 // three different sources: 5136 // 5137 // 1. User option -XX:ActiveProcessorCount 5138 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN) 5139 // 3. extracted from cgroup cpu subsystem (shares and quotas) 5140 // 5141 // Option 1, if specified, will always override. 5142 // If the cgroup subsystem is active and configured, we 5143 // will return the min of the cgroup and option 2 results. 5144 // This is required since tools, such as numactl, that 5145 // alter cpu affinity do not update cgroup subsystem 5146 // cpuset configuration files. 5147 int os::active_processor_count() { 5148 // User has overridden the number of active processors 5149 if (ActiveProcessorCount > 0) { 5150 log_trace(os)("active_processor_count: " 5151 "active processor count set by user : %d", 5152 ActiveProcessorCount); 5153 return ActiveProcessorCount; 5154 } 5155 5156 int active_cpus; 5157 if (OSContainer::is_containerized()) { 5158 active_cpus = OSContainer::active_processor_count(); 5159 log_trace(os)("active_processor_count: determined by OSContainer: %d", 5160 active_cpus); 5161 } else { 5162 active_cpus = os::Linux::active_processor_count(); 5163 } 5164 5165 return active_cpus; 5166 } 5167 5168 void os::set_native_thread_name(const char *name) { 5169 if (Linux::_pthread_setname_np) { 5170 char buf [16]; // according to glibc manpage, 16 chars incl. '/0' 5171 snprintf(buf, sizeof(buf), "%s", name); 5172 buf[sizeof(buf) - 1] = '\0'; 5173 const int rc = Linux::_pthread_setname_np(pthread_self(), buf); 5174 // ERANGE should not happen; all other errors should just be ignored. 5175 assert(rc != ERANGE, "pthread_setname_np failed"); 5176 } 5177 } 5178 5179 bool os::distribute_processes(uint length, uint* distribution) { 5180 // Not yet implemented. 5181 return false; 5182 } 5183 5184 bool os::bind_to_processor(uint processor_id) { 5185 // Not yet implemented. 5186 return false; 5187 } 5188 5189 /// 5190 5191 void os::SuspendedThreadTask::internal_do_task() { 5192 if (do_suspend(_thread->osthread())) { 5193 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 5194 do_task(context); 5195 do_resume(_thread->osthread()); 5196 } 5197 } 5198 5199 //////////////////////////////////////////////////////////////////////////////// 5200 // debug support 5201 5202 bool os::find(address addr, outputStream* st) { 5203 Dl_info dlinfo; 5204 memset(&dlinfo, 0, sizeof(dlinfo)); 5205 if (dladdr(addr, &dlinfo) != 0) { 5206 st->print(PTR_FORMAT ": ", p2i(addr)); 5207 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 5208 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname, 5209 p2i(addr) - p2i(dlinfo.dli_saddr)); 5210 } else if (dlinfo.dli_fbase != NULL) { 5211 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase)); 5212 } else { 5213 st->print("<absolute address>"); 5214 } 5215 if (dlinfo.dli_fname != NULL) { 5216 st->print(" in %s", dlinfo.dli_fname); 5217 } 5218 if (dlinfo.dli_fbase != NULL) { 5219 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase)); 5220 } 5221 st->cr(); 5222 5223 if (Verbose) { 5224 // decode some bytes around the PC 5225 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 5226 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 5227 address lowest = (address) dlinfo.dli_sname; 5228 if (!lowest) lowest = (address) dlinfo.dli_fbase; 5229 if (begin < lowest) begin = lowest; 5230 Dl_info dlinfo2; 5231 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 5232 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 5233 end = (address) dlinfo2.dli_saddr; 5234 } 5235 Disassembler::decode(begin, end, st); 5236 } 5237 return true; 5238 } 5239 return false; 5240 } 5241 5242 //////////////////////////////////////////////////////////////////////////////// 5243 // misc 5244 5245 // This does not do anything on Linux. This is basically a hook for being 5246 // able to use structured exception handling (thread-local exception filters) 5247 // on, e.g., Win32. 5248 void 5249 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, 5250 JavaCallArguments* args, Thread* thread) { 5251 f(value, method, args, thread); 5252 } 5253 5254 void os::print_statistics() { 5255 } 5256 5257 bool os::message_box(const char* title, const char* message) { 5258 int i; 5259 fdStream err(defaultStream::error_fd()); 5260 for (i = 0; i < 78; i++) err.print_raw("="); 5261 err.cr(); 5262 err.print_raw_cr(title); 5263 for (i = 0; i < 78; i++) err.print_raw("-"); 5264 err.cr(); 5265 err.print_raw_cr(message); 5266 for (i = 0; i < 78; i++) err.print_raw("="); 5267 err.cr(); 5268 5269 char buf[16]; 5270 // Prevent process from exiting upon "read error" without consuming all CPU 5271 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 5272 5273 return buf[0] == 'y' || buf[0] == 'Y'; 5274 } 5275 5276 int os::stat(const char *path, struct stat *sbuf) { 5277 char pathbuf[MAX_PATH]; 5278 if (strlen(path) > MAX_PATH - 1) { 5279 errno = ENAMETOOLONG; 5280 return -1; 5281 } 5282 os::native_path(strcpy(pathbuf, path)); 5283 return ::stat(pathbuf, sbuf); 5284 } 5285 5286 // Is a (classpath) directory empty? 5287 bool os::dir_is_empty(const char* path) { 5288 DIR *dir = NULL; 5289 struct dirent *ptr; 5290 5291 dir = opendir(path); 5292 if (dir == NULL) return true; 5293 5294 // Scan the directory 5295 bool result = true; 5296 char buf[sizeof(struct dirent) + MAX_PATH]; 5297 while (result && (ptr = ::readdir(dir)) != NULL) { 5298 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 5299 result = false; 5300 } 5301 } 5302 closedir(dir); 5303 return result; 5304 } 5305 5306 // This code originates from JDK's sysOpen and open64_w 5307 // from src/solaris/hpi/src/system_md.c 5308 5309 int os::open(const char *path, int oflag, int mode) { 5310 if (strlen(path) > MAX_PATH - 1) { 5311 errno = ENAMETOOLONG; 5312 return -1; 5313 } 5314 5315 // All file descriptors that are opened in the Java process and not 5316 // specifically destined for a subprocess should have the close-on-exec 5317 // flag set. If we don't set it, then careless 3rd party native code 5318 // might fork and exec without closing all appropriate file descriptors 5319 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in 5320 // turn might: 5321 // 5322 // - cause end-of-file to fail to be detected on some file 5323 // descriptors, resulting in mysterious hangs, or 5324 // 5325 // - might cause an fopen in the subprocess to fail on a system 5326 // suffering from bug 1085341. 5327 // 5328 // (Yes, the default setting of the close-on-exec flag is a Unix 5329 // design flaw) 5330 // 5331 // See: 5332 // 1085341: 32-bit stdio routines should support file descriptors >255 5333 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 5334 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 5335 // 5336 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open(). 5337 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor 5338 // because it saves a system call and removes a small window where the flag 5339 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored 5340 // and we fall back to using FD_CLOEXEC (see below). 5341 #ifdef O_CLOEXEC 5342 oflag |= O_CLOEXEC; 5343 #endif 5344 5345 int fd = ::open64(path, oflag, mode); 5346 if (fd == -1) return -1; 5347 5348 //If the open succeeded, the file might still be a directory 5349 { 5350 struct stat64 buf64; 5351 int ret = ::fstat64(fd, &buf64); 5352 int st_mode = buf64.st_mode; 5353 5354 if (ret != -1) { 5355 if ((st_mode & S_IFMT) == S_IFDIR) { 5356 errno = EISDIR; 5357 ::close(fd); 5358 return -1; 5359 } 5360 } else { 5361 ::close(fd); 5362 return -1; 5363 } 5364 } 5365 5366 #ifdef FD_CLOEXEC 5367 // Validate that the use of the O_CLOEXEC flag on open above worked. 5368 // With recent kernels, we will perform this check exactly once. 5369 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0; 5370 if (!O_CLOEXEC_is_known_to_work) { 5371 int flags = ::fcntl(fd, F_GETFD); 5372 if (flags != -1) { 5373 if ((flags & FD_CLOEXEC) != 0) 5374 O_CLOEXEC_is_known_to_work = 1; 5375 else 5376 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 5377 } 5378 } 5379 #endif 5380 5381 return fd; 5382 } 5383 5384 5385 // create binary file, rewriting existing file if required 5386 int os::create_binary_file(const char* path, bool rewrite_existing) { 5387 int oflags = O_WRONLY | O_CREAT; 5388 if (!rewrite_existing) { 5389 oflags |= O_EXCL; 5390 } 5391 return ::open64(path, oflags, S_IREAD | S_IWRITE); 5392 } 5393 5394 // return current position of file pointer 5395 jlong os::current_file_offset(int fd) { 5396 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR); 5397 } 5398 5399 // move file pointer to the specified offset 5400 jlong os::seek_to_file_offset(int fd, jlong offset) { 5401 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET); 5402 } 5403 5404 // This code originates from JDK's sysAvailable 5405 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 5406 5407 int os::available(int fd, jlong *bytes) { 5408 jlong cur, end; 5409 int mode; 5410 struct stat64 buf64; 5411 5412 if (::fstat64(fd, &buf64) >= 0) { 5413 mode = buf64.st_mode; 5414 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 5415 int n; 5416 if (::ioctl(fd, FIONREAD, &n) >= 0) { 5417 *bytes = n; 5418 return 1; 5419 } 5420 } 5421 } 5422 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) { 5423 return 0; 5424 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) { 5425 return 0; 5426 } else if (::lseek64(fd, cur, SEEK_SET) == -1) { 5427 return 0; 5428 } 5429 *bytes = end - cur; 5430 return 1; 5431 } 5432 5433 // Map a block of memory. 5434 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 5435 char *addr, size_t bytes, bool read_only, 5436 bool allow_exec) { 5437 int prot; 5438 int flags = MAP_PRIVATE; 5439 5440 if (read_only) { 5441 prot = PROT_READ; 5442 } else { 5443 prot = PROT_READ | PROT_WRITE; 5444 } 5445 5446 if (allow_exec) { 5447 prot |= PROT_EXEC; 5448 } 5449 5450 if (addr != NULL) { 5451 flags |= MAP_FIXED; 5452 } 5453 5454 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 5455 fd, file_offset); 5456 if (mapped_address == MAP_FAILED) { 5457 return NULL; 5458 } 5459 return mapped_address; 5460 } 5461 5462 5463 // Remap a block of memory. 5464 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 5465 char *addr, size_t bytes, bool read_only, 5466 bool allow_exec) { 5467 // same as map_memory() on this OS 5468 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 5469 allow_exec); 5470 } 5471 5472 5473 // Unmap a block of memory. 5474 bool os::pd_unmap_memory(char* addr, size_t bytes) { 5475 return munmap(addr, bytes) == 0; 5476 } 5477 5478 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); 5479 5480 static clockid_t thread_cpu_clockid(Thread* thread) { 5481 pthread_t tid = thread->osthread()->pthread_id(); 5482 clockid_t clockid; 5483 5484 // Get thread clockid 5485 int rc = os::Linux::pthread_getcpuclockid(tid, &clockid); 5486 assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code"); 5487 return clockid; 5488 } 5489 5490 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 5491 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 5492 // of a thread. 5493 // 5494 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 5495 // the fast estimate available on the platform. 5496 5497 jlong os::current_thread_cpu_time() { 5498 if (os::Linux::supports_fast_thread_cpu_time()) { 5499 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5500 } else { 5501 // return user + sys since the cost is the same 5502 return slow_thread_cpu_time(Thread::current(), true /* user + sys */); 5503 } 5504 } 5505 5506 jlong os::thread_cpu_time(Thread* thread) { 5507 // consistent with what current_thread_cpu_time() returns 5508 if (os::Linux::supports_fast_thread_cpu_time()) { 5509 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5510 } else { 5511 return slow_thread_cpu_time(thread, true /* user + sys */); 5512 } 5513 } 5514 5515 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 5516 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5517 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5518 } else { 5519 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); 5520 } 5521 } 5522 5523 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5524 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5525 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5526 } else { 5527 return slow_thread_cpu_time(thread, user_sys_cpu_time); 5528 } 5529 } 5530 5531 // -1 on error. 5532 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5533 pid_t tid = thread->osthread()->thread_id(); 5534 char *s; 5535 char stat[2048]; 5536 int statlen; 5537 char proc_name[64]; 5538 int count; 5539 long sys_time, user_time; 5540 char cdummy; 5541 int idummy; 5542 long ldummy; 5543 FILE *fp; 5544 5545 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid); 5546 fp = fopen(proc_name, "r"); 5547 if (fp == NULL) return -1; 5548 statlen = fread(stat, 1, 2047, fp); 5549 stat[statlen] = '\0'; 5550 fclose(fp); 5551 5552 // Skip pid and the command string. Note that we could be dealing with 5553 // weird command names, e.g. user could decide to rename java launcher 5554 // to "java 1.4.2 :)", then the stat file would look like 5555 // 1234 (java 1.4.2 :)) R ... ... 5556 // We don't really need to know the command string, just find the last 5557 // occurrence of ")" and then start parsing from there. See bug 4726580. 5558 s = strrchr(stat, ')'); 5559 if (s == NULL) return -1; 5560 5561 // Skip blank chars 5562 do { s++; } while (s && isspace(*s)); 5563 5564 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", 5565 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy, 5566 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, 5567 &user_time, &sys_time); 5568 if (count != 13) return -1; 5569 if (user_sys_cpu_time) { 5570 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); 5571 } else { 5572 return (jlong)user_time * (1000000000 / clock_tics_per_sec); 5573 } 5574 } 5575 5576 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5577 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5578 info_ptr->may_skip_backward = false; // elapsed time not wall time 5579 info_ptr->may_skip_forward = false; // elapsed time not wall time 5580 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5581 } 5582 5583 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5584 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5585 info_ptr->may_skip_backward = false; // elapsed time not wall time 5586 info_ptr->may_skip_forward = false; // elapsed time not wall time 5587 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5588 } 5589 5590 bool os::is_thread_cpu_time_supported() { 5591 return true; 5592 } 5593 5594 // System loadavg support. Returns -1 if load average cannot be obtained. 5595 // Linux doesn't yet have a (official) notion of processor sets, 5596 // so just return the system wide load average. 5597 int os::loadavg(double loadavg[], int nelem) { 5598 return ::getloadavg(loadavg, nelem); 5599 } 5600 5601 void os::pause() { 5602 char filename[MAX_PATH]; 5603 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 5604 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile); 5605 } else { 5606 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 5607 } 5608 5609 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 5610 if (fd != -1) { 5611 struct stat buf; 5612 ::close(fd); 5613 while (::stat(filename, &buf) == 0) { 5614 (void)::poll(NULL, 0, 100); 5615 } 5616 } else { 5617 jio_fprintf(stderr, 5618 "Could not open pause file '%s', continuing immediately.\n", filename); 5619 } 5620 } 5621 5622 extern char** environ; 5623 5624 // Run the specified command in a separate process. Return its exit value, 5625 // or -1 on failure (e.g. can't fork a new process). 5626 // Unlike system(), this function can be called from signal handler. It 5627 // doesn't block SIGINT et al. 5628 int os::fork_and_exec(char* cmd) { 5629 const char * argv[4] = {"sh", "-c", cmd, NULL}; 5630 5631 pid_t pid = fork(); 5632 5633 if (pid < 0) { 5634 // fork failed 5635 return -1; 5636 5637 } else if (pid == 0) { 5638 // child process 5639 5640 execve("/bin/sh", (char* const*)argv, environ); 5641 5642 // execve failed 5643 _exit(-1); 5644 5645 } else { 5646 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 5647 // care about the actual exit code, for now. 5648 5649 int status; 5650 5651 // Wait for the child process to exit. This returns immediately if 5652 // the child has already exited. */ 5653 while (waitpid(pid, &status, 0) < 0) { 5654 switch (errno) { 5655 case ECHILD: return 0; 5656 case EINTR: break; 5657 default: return -1; 5658 } 5659 } 5660 5661 if (WIFEXITED(status)) { 5662 // The child exited normally; get its exit code. 5663 return WEXITSTATUS(status); 5664 } else if (WIFSIGNALED(status)) { 5665 // The child exited because of a signal 5666 // The best value to return is 0x80 + signal number, 5667 // because that is what all Unix shells do, and because 5668 // it allows callers to distinguish between process exit and 5669 // process death by signal. 5670 return 0x80 + WTERMSIG(status); 5671 } else { 5672 // Unknown exit code; pass it through 5673 return status; 5674 } 5675 } 5676 } 5677 5678 // Get the default path to the core file 5679 // Returns the length of the string 5680 int os::get_core_path(char* buffer, size_t bufferSize) { 5681 /* 5682 * Max length of /proc/sys/kernel/core_pattern is 128 characters. 5683 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt 5684 */ 5685 const int core_pattern_len = 129; 5686 char core_pattern[core_pattern_len] = {0}; 5687 5688 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY); 5689 if (core_pattern_file == -1) { 5690 return -1; 5691 } 5692 5693 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len); 5694 ::close(core_pattern_file); 5695 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') { 5696 return -1; 5697 } 5698 if (core_pattern[ret-1] == '\n') { 5699 core_pattern[ret-1] = '\0'; 5700 } else { 5701 core_pattern[ret] = '\0'; 5702 } 5703 5704 char *pid_pos = strstr(core_pattern, "%p"); 5705 int written; 5706 5707 if (core_pattern[0] == '/') { 5708 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern); 5709 } else { 5710 char cwd[PATH_MAX]; 5711 5712 const char* p = get_current_directory(cwd, PATH_MAX); 5713 if (p == NULL) { 5714 return -1; 5715 } 5716 5717 if (core_pattern[0] == '|') { 5718 written = jio_snprintf(buffer, bufferSize, 5719 "\"%s\" (or dumping to %s/core.%d)", 5720 &core_pattern[1], p, current_process_id()); 5721 } else { 5722 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern); 5723 } 5724 } 5725 5726 if (written < 0) { 5727 return -1; 5728 } 5729 5730 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) { 5731 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY); 5732 5733 if (core_uses_pid_file != -1) { 5734 char core_uses_pid = 0; 5735 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1); 5736 ::close(core_uses_pid_file); 5737 5738 if (core_uses_pid == '1') { 5739 jio_snprintf(buffer + written, bufferSize - written, 5740 ".%d", current_process_id()); 5741 } 5742 } 5743 } 5744 5745 return strlen(buffer); 5746 } 5747 5748 bool os::start_debugging(char *buf, int buflen) { 5749 int len = (int)strlen(buf); 5750 char *p = &buf[len]; 5751 5752 jio_snprintf(p, buflen-len, 5753 "\n\n" 5754 "Do you want to debug the problem?\n\n" 5755 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n" 5756 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n" 5757 "Otherwise, press RETURN to abort...", 5758 os::current_process_id(), os::current_process_id(), 5759 os::current_thread_id(), os::current_thread_id()); 5760 5761 bool yes = os::message_box("Unexpected Error", buf); 5762 5763 if (yes) { 5764 // yes, user asked VM to launch debugger 5765 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d", 5766 os::current_process_id(), os::current_process_id()); 5767 5768 os::fork_and_exec(buf); 5769 yes = false; 5770 } 5771 return yes; 5772 } 5773 5774 5775 // Java/Compiler thread: 5776 // 5777 // Low memory addresses 5778 // P0 +------------------------+ 5779 // | |\ Java thread created by VM does not have glibc 5780 // | glibc guard page | - guard page, attached Java thread usually has 5781 // | |/ 1 glibc guard page. 5782 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 5783 // | |\ 5784 // | HotSpot Guard Pages | - red, yellow and reserved pages 5785 // | |/ 5786 // +------------------------+ JavaThread::stack_reserved_zone_base() 5787 // | |\ 5788 // | Normal Stack | - 5789 // | |/ 5790 // P2 +------------------------+ Thread::stack_base() 5791 // 5792 // Non-Java thread: 5793 // 5794 // Low memory addresses 5795 // P0 +------------------------+ 5796 // | |\ 5797 // | glibc guard page | - usually 1 page 5798 // | |/ 5799 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 5800 // | |\ 5801 // | Normal Stack | - 5802 // | |/ 5803 // P2 +------------------------+ Thread::stack_base() 5804 // 5805 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size 5806 // returned from pthread_attr_getstack(). 5807 // ** Due to NPTL implementation error, linux takes the glibc guard page out 5808 // of the stack size given in pthread_attr. We work around this for 5809 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.) 5810 // 5811 #ifndef ZERO 5812 static void current_stack_region(address * bottom, size_t * size) { 5813 if (os::is_primordial_thread()) { 5814 // primordial thread needs special handling because pthread_getattr_np() 5815 // may return bogus value. 5816 *bottom = os::Linux::initial_thread_stack_bottom(); 5817 *size = os::Linux::initial_thread_stack_size(); 5818 } else { 5819 pthread_attr_t attr; 5820 5821 int rslt = pthread_getattr_np(pthread_self(), &attr); 5822 5823 // JVM needs to know exact stack location, abort if it fails 5824 if (rslt != 0) { 5825 if (rslt == ENOMEM) { 5826 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); 5827 } else { 5828 fatal("pthread_getattr_np failed with error = %d", rslt); 5829 } 5830 } 5831 5832 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { 5833 fatal("Cannot locate current stack attributes!"); 5834 } 5835 5836 // Work around NPTL stack guard error. 5837 size_t guard_size = 0; 5838 rslt = pthread_attr_getguardsize(&attr, &guard_size); 5839 if (rslt != 0) { 5840 fatal("pthread_attr_getguardsize failed with error = %d", rslt); 5841 } 5842 *bottom += guard_size; 5843 *size -= guard_size; 5844 5845 pthread_attr_destroy(&attr); 5846 5847 } 5848 assert(os::current_stack_pointer() >= *bottom && 5849 os::current_stack_pointer() < *bottom + *size, "just checking"); 5850 } 5851 5852 address os::current_stack_base() { 5853 address bottom; 5854 size_t size; 5855 current_stack_region(&bottom, &size); 5856 return (bottom + size); 5857 } 5858 5859 size_t os::current_stack_size() { 5860 // This stack size includes the usable stack and HotSpot guard pages 5861 // (for the threads that have Hotspot guard pages). 5862 address bottom; 5863 size_t size; 5864 current_stack_region(&bottom, &size); 5865 return size; 5866 } 5867 #endif 5868 5869 static inline struct timespec get_mtime(const char* filename) { 5870 struct stat st; 5871 int ret = os::stat(filename, &st); 5872 assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno)); 5873 return st.st_mtim; 5874 } 5875 5876 int os::compare_file_modified_times(const char* file1, const char* file2) { 5877 struct timespec filetime1 = get_mtime(file1); 5878 struct timespec filetime2 = get_mtime(file2); 5879 int diff = filetime1.tv_sec - filetime2.tv_sec; 5880 if (diff == 0) { 5881 return filetime1.tv_nsec - filetime2.tv_nsec; 5882 } 5883 return diff; 5884 } 5885 5886 /////////////// Unit tests /////////////// 5887 5888 #ifndef PRODUCT 5889 5890 #define test_log(...) \ 5891 do { \ 5892 if (VerboseInternalVMTests) { \ 5893 tty->print_cr(__VA_ARGS__); \ 5894 tty->flush(); \ 5895 } \ 5896 } while (false) 5897 5898 class TestReserveMemorySpecial : AllStatic { 5899 public: 5900 static void small_page_write(void* addr, size_t size) { 5901 size_t page_size = os::vm_page_size(); 5902 5903 char* end = (char*)addr + size; 5904 for (char* p = (char*)addr; p < end; p += page_size) { 5905 *p = 1; 5906 } 5907 } 5908 5909 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) { 5910 if (!UseHugeTLBFS) { 5911 return; 5912 } 5913 5914 test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size); 5915 5916 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false); 5917 5918 if (addr != NULL) { 5919 small_page_write(addr, size); 5920 5921 os::Linux::release_memory_special_huge_tlbfs(addr, size); 5922 } 5923 } 5924 5925 static void test_reserve_memory_special_huge_tlbfs_only() { 5926 if (!UseHugeTLBFS) { 5927 return; 5928 } 5929 5930 size_t lp = os::large_page_size(); 5931 5932 for (size_t size = lp; size <= lp * 10; size += lp) { 5933 test_reserve_memory_special_huge_tlbfs_only(size); 5934 } 5935 } 5936 5937 static void test_reserve_memory_special_huge_tlbfs_mixed() { 5938 size_t lp = os::large_page_size(); 5939 size_t ag = os::vm_allocation_granularity(); 5940 5941 // sizes to test 5942 const size_t sizes[] = { 5943 lp, lp + ag, lp + lp / 2, lp * 2, 5944 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2, 5945 lp * 10, lp * 10 + lp / 2 5946 }; 5947 const int num_sizes = sizeof(sizes) / sizeof(size_t); 5948 5949 // For each size/alignment combination, we test three scenarios: 5950 // 1) with req_addr == NULL 5951 // 2) with a non-null req_addr at which we expect to successfully allocate 5952 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we 5953 // expect the allocation to either fail or to ignore req_addr 5954 5955 // Pre-allocate two areas; they shall be as large as the largest allocation 5956 // and aligned to the largest alignment we will be testing. 5957 const size_t mapping_size = sizes[num_sizes - 1] * 2; 5958 char* const mapping1 = (char*) ::mmap(NULL, mapping_size, 5959 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 5960 -1, 0); 5961 assert(mapping1 != MAP_FAILED, "should work"); 5962 5963 char* const mapping2 = (char*) ::mmap(NULL, mapping_size, 5964 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 5965 -1, 0); 5966 assert(mapping2 != MAP_FAILED, "should work"); 5967 5968 // Unmap the first mapping, but leave the second mapping intact: the first 5969 // mapping will serve as a value for a "good" req_addr (case 2). The second 5970 // mapping, still intact, as "bad" req_addr (case 3). 5971 ::munmap(mapping1, mapping_size); 5972 5973 // Case 1 5974 test_log("%s, req_addr NULL:", __FUNCTION__); 5975 test_log("size align result"); 5976 5977 for (int i = 0; i < num_sizes; i++) { 5978 const size_t size = sizes[i]; 5979 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 5980 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false); 5981 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s", 5982 size, alignment, p2i(p), (p != NULL ? "" : "(failed)")); 5983 if (p != NULL) { 5984 assert(is_aligned(p, alignment), "must be"); 5985 small_page_write(p, size); 5986 os::Linux::release_memory_special_huge_tlbfs(p, size); 5987 } 5988 } 5989 } 5990 5991 // Case 2 5992 test_log("%s, req_addr non-NULL:", __FUNCTION__); 5993 test_log("size align req_addr result"); 5994 5995 for (int i = 0; i < num_sizes; i++) { 5996 const size_t size = sizes[i]; 5997 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 5998 char* const req_addr = align_up(mapping1, alignment); 5999 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 6000 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 6001 size, alignment, p2i(req_addr), p2i(p), 6002 ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)"))); 6003 if (p != NULL) { 6004 assert(p == req_addr, "must be"); 6005 small_page_write(p, size); 6006 os::Linux::release_memory_special_huge_tlbfs(p, size); 6007 } 6008 } 6009 } 6010 6011 // Case 3 6012 test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__); 6013 test_log("size align req_addr result"); 6014 6015 for (int i = 0; i < num_sizes; i++) { 6016 const size_t size = sizes[i]; 6017 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6018 char* const req_addr = align_up(mapping2, alignment); 6019 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 6020 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 6021 size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)"))); 6022 // as the area around req_addr contains already existing mappings, the API should always 6023 // return NULL (as per contract, it cannot return another address) 6024 assert(p == NULL, "must be"); 6025 } 6026 } 6027 6028 ::munmap(mapping2, mapping_size); 6029 6030 } 6031 6032 static void test_reserve_memory_special_huge_tlbfs() { 6033 if (!UseHugeTLBFS) { 6034 return; 6035 } 6036 6037 test_reserve_memory_special_huge_tlbfs_only(); 6038 test_reserve_memory_special_huge_tlbfs_mixed(); 6039 } 6040 6041 static void test_reserve_memory_special_shm(size_t size, size_t alignment) { 6042 if (!UseSHM) { 6043 return; 6044 } 6045 6046 test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment); 6047 6048 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false); 6049 6050 if (addr != NULL) { 6051 assert(is_aligned(addr, alignment), "Check"); 6052 assert(is_aligned(addr, os::large_page_size()), "Check"); 6053 6054 small_page_write(addr, size); 6055 6056 os::Linux::release_memory_special_shm(addr, size); 6057 } 6058 } 6059 6060 static void test_reserve_memory_special_shm() { 6061 size_t lp = os::large_page_size(); 6062 size_t ag = os::vm_allocation_granularity(); 6063 6064 for (size_t size = ag; size < lp * 3; size += ag) { 6065 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6066 test_reserve_memory_special_shm(size, alignment); 6067 } 6068 } 6069 } 6070 6071 static void test() { 6072 test_reserve_memory_special_huge_tlbfs(); 6073 test_reserve_memory_special_shm(); 6074 } 6075 }; 6076 6077 void TestReserveMemorySpecial_test() { 6078 TestReserveMemorySpecial::test(); 6079 } 6080 6081 #endif