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.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 // If the VM might have been created on the primordial thread, we need to resolve the 156 // primordial thread stack bounds and check if the current thread might be the 157 // primordial thread in places. If we know that the primordial thread is never used, 158 // such as when the VM was created by one of the standard java launchers, we can 159 // avoid this 160 static bool suppress_primordial_thread_resolution = false; 161 162 // For diagnostics to print a message once. see run_periodic_checks 163 static sigset_t check_signal_done; 164 static bool check_signals = true; 165 166 // Signal number used to suspend/resume a thread 167 168 // do not use any signal number less than SIGSEGV, see 4355769 169 static int SR_signum = SIGUSR2; 170 sigset_t SR_sigset; 171 172 // utility functions 173 174 static int SR_initialize(); 175 176 julong os::available_memory() { 177 return Linux::available_memory(); 178 } 179 180 julong os::Linux::available_memory() { 181 // values in struct sysinfo are "unsigned long" 182 struct sysinfo si; 183 julong avail_mem; 184 185 if (OSContainer::is_containerized()) { 186 jlong mem_limit, mem_usage; 187 if ((mem_limit = OSContainer::memory_limit_in_bytes()) < 1) { 188 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value", 189 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit); 190 } 191 if (mem_limit > 0 && (mem_usage = OSContainer::memory_usage_in_bytes()) < 1) { 192 log_debug(os, container)("container memory usage failed: " JLONG_FORMAT ", using host value", mem_usage); 193 } 194 if (mem_limit > 0 && mem_usage > 0 ) { 195 avail_mem = mem_limit > mem_usage ? (julong)mem_limit - (julong)mem_usage : 0; 196 log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem); 197 return avail_mem; 198 } 199 } 200 201 sysinfo(&si); 202 avail_mem = (julong)si.freeram * si.mem_unit; 203 log_trace(os)("available memory: " JULONG_FORMAT, avail_mem); 204 return avail_mem; 205 } 206 207 julong os::physical_memory() { 208 jlong phys_mem = 0; 209 if (OSContainer::is_containerized()) { 210 jlong mem_limit; 211 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) { 212 log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit); 213 return mem_limit; 214 } 215 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value", 216 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit); 217 } 218 219 phys_mem = Linux::physical_memory(); 220 log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem); 221 return phys_mem; 222 } 223 224 // Return true if user is running as root. 225 226 bool os::have_special_privileges() { 227 static bool init = false; 228 static bool privileges = false; 229 if (!init) { 230 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 231 init = true; 232 } 233 return privileges; 234 } 235 236 237 #ifndef SYS_gettid 238 // i386: 224, ia64: 1105, amd64: 186, sparc 143 239 #ifdef __ia64__ 240 #define SYS_gettid 1105 241 #else 242 #ifdef __i386__ 243 #define SYS_gettid 224 244 #else 245 #ifdef __amd64__ 246 #define SYS_gettid 186 247 #else 248 #ifdef __sparc__ 249 #define SYS_gettid 143 250 #else 251 #error define gettid for the arch 252 #endif 253 #endif 254 #endif 255 #endif 256 #endif 257 258 259 // pid_t gettid() 260 // 261 // Returns the kernel thread id of the currently running thread. Kernel 262 // thread id is used to access /proc. 263 pid_t os::Linux::gettid() { 264 int rslt = syscall(SYS_gettid); 265 assert(rslt != -1, "must be."); // old linuxthreads implementation? 266 return (pid_t)rslt; 267 } 268 269 // Most versions of linux have a bug where the number of processors are 270 // determined by looking at the /proc file system. In a chroot environment, 271 // the system call returns 1. This causes the VM to act as if it is 272 // a single processor and elide locking (see is_MP() call). 273 static bool unsafe_chroot_detected = false; 274 static const char *unstable_chroot_error = "/proc file system not found.\n" 275 "Java may be unstable running multithreaded in a chroot " 276 "environment on Linux when /proc filesystem is not mounted."; 277 278 void os::Linux::initialize_system_info() { 279 set_processor_count(sysconf(_SC_NPROCESSORS_CONF)); 280 if (processor_count() == 1) { 281 pid_t pid = os::Linux::gettid(); 282 char fname[32]; 283 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid); 284 FILE *fp = fopen(fname, "r"); 285 if (fp == NULL) { 286 unsafe_chroot_detected = true; 287 } else { 288 fclose(fp); 289 } 290 } 291 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE); 292 assert(processor_count() > 0, "linux error"); 293 } 294 295 void os::init_system_properties_values() { 296 // The next steps are taken in the product version: 297 // 298 // Obtain the JAVA_HOME value from the location of libjvm.so. 299 // This library should be located at: 300 // <JAVA_HOME>/lib/{client|server}/libjvm.so. 301 // 302 // If "/jre/lib/" appears at the right place in the path, then we 303 // assume libjvm.so is installed in a JDK and we use this path. 304 // 305 // Otherwise exit with message: "Could not create the Java virtual machine." 306 // 307 // The following extra steps are taken in the debugging version: 308 // 309 // If "/jre/lib/" does NOT appear at the right place in the path 310 // instead of exit check for $JAVA_HOME environment variable. 311 // 312 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 313 // then we append a fake suffix "hotspot/libjvm.so" to this path so 314 // it looks like libjvm.so is installed there 315 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 316 // 317 // Otherwise exit. 318 // 319 // Important note: if the location of libjvm.so changes this 320 // code needs to be changed accordingly. 321 322 // See ld(1): 323 // The linker uses the following search paths to locate required 324 // shared libraries: 325 // 1: ... 326 // ... 327 // 7: The default directories, normally /lib and /usr/lib. 328 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390) 329 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib" 330 #else 331 #define DEFAULT_LIBPATH "/lib:/usr/lib" 332 #endif 333 334 // Base path of extensions installed on the system. 335 #define SYS_EXT_DIR "/usr/java/packages" 336 #define EXTENSIONS_DIR "/lib/ext" 337 338 // Buffer that fits several sprintfs. 339 // Note that the space for the colon and the trailing null are provided 340 // by the nulls included by the sizeof operator. 341 const size_t bufsize = 342 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 343 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 344 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 345 346 // sysclasspath, java_home, dll_dir 347 { 348 char *pslash; 349 os::jvm_path(buf, bufsize); 350 351 // Found the full path to libjvm.so. 352 // Now cut the path to <java_home>/jre if we can. 353 pslash = strrchr(buf, '/'); 354 if (pslash != NULL) { 355 *pslash = '\0'; // Get rid of /libjvm.so. 356 } 357 pslash = strrchr(buf, '/'); 358 if (pslash != NULL) { 359 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 360 } 361 Arguments::set_dll_dir(buf); 362 363 if (pslash != NULL) { 364 pslash = strrchr(buf, '/'); 365 if (pslash != NULL) { 366 *pslash = '\0'; // Get rid of /lib. 367 } 368 } 369 Arguments::set_java_home(buf); 370 if (!set_boot_path('/', ':')) { 371 vm_exit_during_initialization("Failed setting boot class path.", NULL); 372 } 373 } 374 375 // Where to look for native libraries. 376 // 377 // Note: Due to a legacy implementation, most of the library path 378 // is set in the launcher. This was to accomodate linking restrictions 379 // on legacy Linux implementations (which are no longer supported). 380 // Eventually, all the library path setting will be done here. 381 // 382 // However, to prevent the proliferation of improperly built native 383 // libraries, the new path component /usr/java/packages is added here. 384 // Eventually, all the library path setting will be done here. 385 { 386 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 387 // should always exist (until the legacy problem cited above is 388 // addressed). 389 const char *v = ::getenv("LD_LIBRARY_PATH"); 390 const char *v_colon = ":"; 391 if (v == NULL) { v = ""; v_colon = ""; } 392 // That's +1 for the colon and +1 for the trailing '\0'. 393 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 394 strlen(v) + 1 + 395 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1, 396 mtInternal); 397 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon); 398 Arguments::set_library_path(ld_library_path); 399 FREE_C_HEAP_ARRAY(char, ld_library_path); 400 } 401 402 // Extensions directories. 403 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 404 Arguments::set_ext_dirs(buf); 405 406 FREE_C_HEAP_ARRAY(char, buf); 407 408 #undef DEFAULT_LIBPATH 409 #undef SYS_EXT_DIR 410 #undef EXTENSIONS_DIR 411 } 412 413 //////////////////////////////////////////////////////////////////////////////// 414 // breakpoint support 415 416 void os::breakpoint() { 417 BREAKPOINT; 418 } 419 420 extern "C" void breakpoint() { 421 // use debugger to set breakpoint here 422 } 423 424 //////////////////////////////////////////////////////////////////////////////// 425 // signal support 426 427 debug_only(static bool signal_sets_initialized = false); 428 static sigset_t unblocked_sigs, vm_sigs; 429 430 void os::Linux::signal_sets_init() { 431 // Should also have an assertion stating we are still single-threaded. 432 assert(!signal_sets_initialized, "Already initialized"); 433 // Fill in signals that are necessarily unblocked for all threads in 434 // the VM. Currently, we unblock the following signals: 435 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 436 // by -Xrs (=ReduceSignalUsage)); 437 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 438 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 439 // the dispositions or masks wrt these signals. 440 // Programs embedding the VM that want to use the above signals for their 441 // own purposes must, at this time, use the "-Xrs" option to prevent 442 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 443 // (See bug 4345157, and other related bugs). 444 // In reality, though, unblocking these signals is really a nop, since 445 // these signals are not blocked by default. 446 sigemptyset(&unblocked_sigs); 447 sigaddset(&unblocked_sigs, SIGILL); 448 sigaddset(&unblocked_sigs, SIGSEGV); 449 sigaddset(&unblocked_sigs, SIGBUS); 450 sigaddset(&unblocked_sigs, SIGFPE); 451 #if defined(PPC64) 452 sigaddset(&unblocked_sigs, SIGTRAP); 453 #endif 454 sigaddset(&unblocked_sigs, SR_signum); 455 456 if (!ReduceSignalUsage) { 457 if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 458 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 459 } 460 if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 461 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 462 } 463 if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 464 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 465 } 466 } 467 // Fill in signals that are blocked by all but the VM thread. 468 sigemptyset(&vm_sigs); 469 if (!ReduceSignalUsage) { 470 sigaddset(&vm_sigs, BREAK_SIGNAL); 471 } 472 debug_only(signal_sets_initialized = true); 473 474 } 475 476 // These are signals that are unblocked while a thread is running Java. 477 // (For some reason, they get blocked by default.) 478 sigset_t* os::Linux::unblocked_signals() { 479 assert(signal_sets_initialized, "Not initialized"); 480 return &unblocked_sigs; 481 } 482 483 // These are the signals that are blocked while a (non-VM) thread is 484 // running Java. Only the VM thread handles these signals. 485 sigset_t* os::Linux::vm_signals() { 486 assert(signal_sets_initialized, "Not initialized"); 487 return &vm_sigs; 488 } 489 490 void os::Linux::hotspot_sigmask(Thread* thread) { 491 492 //Save caller's signal mask before setting VM signal mask 493 sigset_t caller_sigmask; 494 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 495 496 OSThread* osthread = thread->osthread(); 497 osthread->set_caller_sigmask(caller_sigmask); 498 499 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL); 500 501 if (!ReduceSignalUsage) { 502 if (thread->is_VM_thread()) { 503 // Only the VM thread handles BREAK_SIGNAL ... 504 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 505 } else { 506 // ... all other threads block BREAK_SIGNAL 507 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 508 } 509 } 510 } 511 512 ////////////////////////////////////////////////////////////////////////////// 513 // detecting pthread library 514 515 void os::Linux::libpthread_init() { 516 // Save glibc and pthread version strings. 517 #if !defined(_CS_GNU_LIBC_VERSION) || \ 518 !defined(_CS_GNU_LIBPTHREAD_VERSION) 519 #error "glibc too old (< 2.3.2)" 520 #endif 521 522 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); 523 assert(n > 0, "cannot retrieve glibc version"); 524 char *str = (char *)malloc(n, mtInternal); 525 confstr(_CS_GNU_LIBC_VERSION, str, n); 526 os::Linux::set_glibc_version(str); 527 528 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); 529 assert(n > 0, "cannot retrieve pthread version"); 530 str = (char *)malloc(n, mtInternal); 531 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); 532 os::Linux::set_libpthread_version(str); 533 } 534 535 ///////////////////////////////////////////////////////////////////////////// 536 // thread stack expansion 537 538 // os::Linux::manually_expand_stack() takes care of expanding the thread 539 // stack. Note that this is normally not needed: pthread stacks allocate 540 // thread stack using mmap() without MAP_NORESERVE, so the stack is already 541 // committed. Therefore it is not necessary to expand the stack manually. 542 // 543 // Manually expanding the stack was historically needed on LinuxThreads 544 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays 545 // it is kept to deal with very rare corner cases: 546 // 547 // For one, user may run the VM on an own implementation of threads 548 // whose stacks are - like the old LinuxThreads - implemented using 549 // mmap(MAP_GROWSDOWN). 550 // 551 // Also, this coding may be needed if the VM is running on the primordial 552 // thread. Normally we avoid running on the primordial thread; however, 553 // user may still invoke the VM on the primordial thread. 554 // 555 // The following historical comment describes the details about running 556 // on a thread stack allocated with mmap(MAP_GROWSDOWN): 557 558 559 // Force Linux kernel to expand current thread stack. If "bottom" is close 560 // to the stack guard, caller should block all signals. 561 // 562 // MAP_GROWSDOWN: 563 // A special mmap() flag that is used to implement thread stacks. It tells 564 // kernel that the memory region should extend downwards when needed. This 565 // allows early versions of LinuxThreads to only mmap the first few pages 566 // when creating a new thread. Linux kernel will automatically expand thread 567 // stack as needed (on page faults). 568 // 569 // However, because the memory region of a MAP_GROWSDOWN stack can grow on 570 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN 571 // region, it's hard to tell if the fault is due to a legitimate stack 572 // access or because of reading/writing non-exist memory (e.g. buffer 573 // overrun). As a rule, if the fault happens below current stack pointer, 574 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the 575 // application (see Linux kernel fault.c). 576 // 577 // This Linux feature can cause SIGSEGV when VM bangs thread stack for 578 // stack overflow detection. 579 // 580 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do 581 // not use MAP_GROWSDOWN. 582 // 583 // To get around the problem and allow stack banging on Linux, we need to 584 // manually expand thread stack after receiving the SIGSEGV. 585 // 586 // There are two ways to expand thread stack to address "bottom", we used 587 // both of them in JVM before 1.5: 588 // 1. adjust stack pointer first so that it is below "bottom", and then 589 // touch "bottom" 590 // 2. mmap() the page in question 591 // 592 // Now alternate signal stack is gone, it's harder to use 2. For instance, 593 // if current sp is already near the lower end of page 101, and we need to 594 // call mmap() to map page 100, it is possible that part of the mmap() frame 595 // will be placed in page 100. When page 100 is mapped, it is zero-filled. 596 // That will destroy the mmap() frame and cause VM to crash. 597 // 598 // The following code works by adjusting sp first, then accessing the "bottom" 599 // page to force a page fault. Linux kernel will then automatically expand the 600 // stack mapping. 601 // 602 // _expand_stack_to() assumes its frame size is less than page size, which 603 // should always be true if the function is not inlined. 604 605 static void NOINLINE _expand_stack_to(address bottom) { 606 address sp; 607 size_t size; 608 volatile char *p; 609 610 // Adjust bottom to point to the largest address within the same page, it 611 // gives us a one-page buffer if alloca() allocates slightly more memory. 612 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size()); 613 bottom += os::Linux::page_size() - 1; 614 615 // sp might be slightly above current stack pointer; if that's the case, we 616 // will alloca() a little more space than necessary, which is OK. Don't use 617 // os::current_stack_pointer(), as its result can be slightly below current 618 // stack pointer, causing us to not alloca enough to reach "bottom". 619 sp = (address)&sp; 620 621 if (sp > bottom) { 622 size = sp - bottom; 623 p = (volatile char *)alloca(size); 624 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); 625 p[0] = '\0'; 626 } 627 } 628 629 void os::Linux::expand_stack_to(address bottom) { 630 _expand_stack_to(bottom); 631 } 632 633 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) { 634 assert(t!=NULL, "just checking"); 635 assert(t->osthread()->expanding_stack(), "expand should be set"); 636 assert(t->stack_base() != NULL, "stack_base was not initialized"); 637 638 if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) { 639 sigset_t mask_all, old_sigset; 640 sigfillset(&mask_all); 641 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); 642 _expand_stack_to(addr); 643 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); 644 return true; 645 } 646 return false; 647 } 648 649 ////////////////////////////////////////////////////////////////////////////// 650 // create new thread 651 652 // Thread start routine for all newly created threads 653 static void *thread_native_entry(Thread *thread) { 654 // Try to randomize the cache line index of hot stack frames. 655 // This helps when threads of the same stack traces evict each other's 656 // cache lines. The threads can be either from the same JVM instance, or 657 // from different JVM instances. The benefit is especially true for 658 // processors with hyperthreading technology. 659 static int counter = 0; 660 int pid = os::current_process_id(); 661 alloca(((pid ^ counter++) & 7) * 128); 662 663 thread->initialize_thread_current(); 664 665 OSThread* osthread = thread->osthread(); 666 Monitor* sync = osthread->startThread_lock(); 667 668 osthread->set_thread_id(os::current_thread_id()); 669 670 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 671 os::current_thread_id(), (uintx) pthread_self()); 672 673 if (UseNUMA) { 674 int lgrp_id = os::numa_get_group_id(); 675 if (lgrp_id != -1) { 676 thread->set_lgrp_id(lgrp_id); 677 } 678 } 679 // initialize signal mask for this thread 680 os::Linux::hotspot_sigmask(thread); 681 682 // initialize floating point control register 683 os::Linux::init_thread_fpu_state(); 684 685 // handshaking with parent thread 686 { 687 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 688 689 // notify parent thread 690 osthread->set_state(INITIALIZED); 691 sync->notify_all(); 692 693 // wait until os::start_thread() 694 while (osthread->get_state() == INITIALIZED) { 695 sync->wait(Mutex::_no_safepoint_check_flag); 696 } 697 } 698 699 // call one more level start routine 700 thread->run(); 701 702 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 703 os::current_thread_id(), (uintx) pthread_self()); 704 705 // If a thread has not deleted itself ("delete this") as part of its 706 // termination sequence, we have to ensure thread-local-storage is 707 // cleared before we actually terminate. No threads should ever be 708 // deleted asynchronously with respect to their termination. 709 if (Thread::current_or_null_safe() != NULL) { 710 assert(Thread::current_or_null_safe() == thread, "current thread is wrong"); 711 thread->clear_thread_current(); 712 } 713 714 return 0; 715 } 716 717 bool os::create_thread(Thread* thread, ThreadType thr_type, 718 size_t req_stack_size) { 719 assert(thread->osthread() == NULL, "caller responsible"); 720 721 // Allocate the OSThread object 722 OSThread* osthread = new OSThread(NULL, NULL); 723 if (osthread == NULL) { 724 return false; 725 } 726 727 // set the correct thread state 728 osthread->set_thread_type(thr_type); 729 730 // Initial state is ALLOCATED but not INITIALIZED 731 osthread->set_state(ALLOCATED); 732 733 thread->set_osthread(osthread); 734 735 // init thread attributes 736 pthread_attr_t attr; 737 pthread_attr_init(&attr); 738 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 739 740 // Calculate stack size if it's not specified by caller. 741 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size); 742 // In the Linux NPTL pthread implementation the guard size mechanism 743 // is not implemented properly. The posix standard requires adding 744 // the size of the guard pages to the stack size, instead Linux 745 // takes the space out of 'stacksize'. Thus we adapt the requested 746 // stack_size by the size of the guard pages to mimick proper 747 // behaviour. However, be careful not to end up with a size 748 // of zero due to overflow. Don't add the guard page in that case. 749 size_t guard_size = os::Linux::default_guard_size(thr_type); 750 if (stack_size <= SIZE_MAX - guard_size) { 751 stack_size += guard_size; 752 } 753 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned"); 754 755 int status = pthread_attr_setstacksize(&attr, stack_size); 756 assert_status(status == 0, status, "pthread_attr_setstacksize"); 757 758 // Configure glibc guard page. 759 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); 760 761 ThreadState state; 762 763 { 764 pthread_t tid; 765 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread); 766 767 char buf[64]; 768 if (ret == 0) { 769 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ", 770 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 771 } else { 772 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.", 773 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 774 } 775 776 pthread_attr_destroy(&attr); 777 778 if (ret != 0) { 779 // Need to clean up stuff we've allocated so far 780 thread->set_osthread(NULL); 781 delete osthread; 782 return false; 783 } 784 785 // Store pthread info into the OSThread 786 osthread->set_pthread_id(tid); 787 788 // Wait until child thread is either initialized or aborted 789 { 790 Monitor* sync_with_child = osthread->startThread_lock(); 791 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 792 while ((state = osthread->get_state()) == ALLOCATED) { 793 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 794 } 795 } 796 } 797 798 // Aborted due to thread limit being reached 799 if (state == ZOMBIE) { 800 thread->set_osthread(NULL); 801 delete osthread; 802 return false; 803 } 804 805 // The thread is returned suspended (in state INITIALIZED), 806 // and is started higher up in the call chain 807 assert(state == INITIALIZED, "race condition"); 808 return true; 809 } 810 811 ///////////////////////////////////////////////////////////////////////////// 812 // attach existing thread 813 814 // bootstrap the main thread 815 bool os::create_main_thread(JavaThread* thread) { 816 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread"); 817 return create_attached_thread(thread); 818 } 819 820 bool os::create_attached_thread(JavaThread* thread) { 821 #ifdef ASSERT 822 thread->verify_not_published(); 823 #endif 824 825 // Allocate the OSThread object 826 OSThread* osthread = new OSThread(NULL, NULL); 827 828 if (osthread == NULL) { 829 return false; 830 } 831 832 // Store pthread info into the OSThread 833 osthread->set_thread_id(os::Linux::gettid()); 834 osthread->set_pthread_id(::pthread_self()); 835 836 // initialize floating point control register 837 os::Linux::init_thread_fpu_state(); 838 839 // Initial thread state is RUNNABLE 840 osthread->set_state(RUNNABLE); 841 842 thread->set_osthread(osthread); 843 844 if (UseNUMA) { 845 int lgrp_id = os::numa_get_group_id(); 846 if (lgrp_id != -1) { 847 thread->set_lgrp_id(lgrp_id); 848 } 849 } 850 851 if (os::is_primordial_thread()) { 852 // If current thread is primordial thread, its stack is mapped on demand, 853 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map 854 // the entire stack region to avoid SEGV in stack banging. 855 // It is also useful to get around the heap-stack-gap problem on SuSE 856 // kernel (see 4821821 for details). We first expand stack to the top 857 // of yellow zone, then enable stack yellow zone (order is significant, 858 // enabling yellow zone first will crash JVM on SuSE Linux), so there 859 // is no gap between the last two virtual memory regions. 860 861 JavaThread *jt = (JavaThread *)thread; 862 address addr = jt->stack_reserved_zone_base(); 863 assert(addr != NULL, "initialization problem?"); 864 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); 865 866 osthread->set_expanding_stack(); 867 os::Linux::manually_expand_stack(jt, addr); 868 osthread->clear_expanding_stack(); 869 } 870 871 // initialize signal mask for this thread 872 // and save the caller's signal mask 873 os::Linux::hotspot_sigmask(thread); 874 875 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 876 os::current_thread_id(), (uintx) pthread_self()); 877 878 return true; 879 } 880 881 void os::pd_start_thread(Thread* thread) { 882 OSThread * osthread = thread->osthread(); 883 assert(osthread->get_state() != INITIALIZED, "just checking"); 884 Monitor* sync_with_child = osthread->startThread_lock(); 885 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 886 sync_with_child->notify(); 887 } 888 889 // Free Linux resources related to the OSThread 890 void os::free_thread(OSThread* osthread) { 891 assert(osthread != NULL, "osthread not set"); 892 893 // We are told to free resources of the argument thread, 894 // but we can only really operate on the current thread. 895 assert(Thread::current()->osthread() == osthread, 896 "os::free_thread but not current thread"); 897 898 #ifdef ASSERT 899 sigset_t current; 900 sigemptyset(¤t); 901 pthread_sigmask(SIG_SETMASK, NULL, ¤t); 902 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!"); 903 #endif 904 905 // Restore caller's signal mask 906 sigset_t sigmask = osthread->caller_sigmask(); 907 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 908 909 delete osthread; 910 } 911 912 ////////////////////////////////////////////////////////////////////////////// 913 // primordial thread 914 915 // Check if current thread is the primordial thread, similar to Solaris thr_main. 916 bool os::is_primordial_thread(void) { 917 if (suppress_primordial_thread_resolution) { 918 return false; 919 } 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 // thread_id is kernel thread id (similar to Solaris LWP id) 1425 intx os::current_thread_id() { return os::Linux::gettid(); } 1426 int os::current_process_id() { 1427 return ::getpid(); 1428 } 1429 1430 // DLL functions 1431 1432 const char* os::dll_file_extension() { return ".so"; } 1433 1434 // This must be hard coded because it's the system's temporary 1435 // directory not the java application's temp directory, ala java.io.tmpdir. 1436 const char* os::get_temp_directory() { return "/tmp"; } 1437 1438 static bool file_exists(const char* filename) { 1439 struct stat statbuf; 1440 if (filename == NULL || strlen(filename) == 0) { 1441 return false; 1442 } 1443 return os::stat(filename, &statbuf) == 0; 1444 } 1445 1446 // check if addr is inside libjvm.so 1447 bool os::address_is_in_vm(address addr) { 1448 static address libjvm_base_addr; 1449 Dl_info dlinfo; 1450 1451 if (libjvm_base_addr == NULL) { 1452 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1453 libjvm_base_addr = (address)dlinfo.dli_fbase; 1454 } 1455 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1456 } 1457 1458 if (dladdr((void *)addr, &dlinfo) != 0) { 1459 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1460 } 1461 1462 return false; 1463 } 1464 1465 bool os::dll_address_to_function_name(address addr, char *buf, 1466 int buflen, int *offset, 1467 bool demangle) { 1468 // buf is not optional, but offset is optional 1469 assert(buf != NULL, "sanity check"); 1470 1471 Dl_info dlinfo; 1472 1473 if (dladdr((void*)addr, &dlinfo) != 0) { 1474 // see if we have a matching symbol 1475 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1476 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) { 1477 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1478 } 1479 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1480 return true; 1481 } 1482 // no matching symbol so try for just file info 1483 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1484 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1485 buf, buflen, offset, dlinfo.dli_fname, demangle)) { 1486 return true; 1487 } 1488 } 1489 } 1490 1491 buf[0] = '\0'; 1492 if (offset != NULL) *offset = -1; 1493 return false; 1494 } 1495 1496 struct _address_to_library_name { 1497 address addr; // input : memory address 1498 size_t buflen; // size of fname 1499 char* fname; // output: library name 1500 address base; // library base addr 1501 }; 1502 1503 static int address_to_library_name_callback(struct dl_phdr_info *info, 1504 size_t size, void *data) { 1505 int i; 1506 bool found = false; 1507 address libbase = NULL; 1508 struct _address_to_library_name * d = (struct _address_to_library_name *)data; 1509 1510 // iterate through all loadable segments 1511 for (i = 0; i < info->dlpi_phnum; i++) { 1512 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); 1513 if (info->dlpi_phdr[i].p_type == PT_LOAD) { 1514 // base address of a library is the lowest address of its loaded 1515 // segments. 1516 if (libbase == NULL || libbase > segbase) { 1517 libbase = segbase; 1518 } 1519 // see if 'addr' is within current segment 1520 if (segbase <= d->addr && 1521 d->addr < segbase + info->dlpi_phdr[i].p_memsz) { 1522 found = true; 1523 } 1524 } 1525 } 1526 1527 // dlpi_name is NULL or empty if the ELF file is executable, return 0 1528 // so dll_address_to_library_name() can fall through to use dladdr() which 1529 // can figure out executable name from argv[0]. 1530 if (found && info->dlpi_name && info->dlpi_name[0]) { 1531 d->base = libbase; 1532 if (d->fname) { 1533 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); 1534 } 1535 return 1; 1536 } 1537 return 0; 1538 } 1539 1540 bool os::dll_address_to_library_name(address addr, char* buf, 1541 int buflen, int* offset) { 1542 // buf is not optional, but offset is optional 1543 assert(buf != NULL, "sanity check"); 1544 1545 Dl_info dlinfo; 1546 struct _address_to_library_name data; 1547 1548 // There is a bug in old glibc dladdr() implementation that it could resolve 1549 // to wrong library name if the .so file has a base address != NULL. Here 1550 // we iterate through the program headers of all loaded libraries to find 1551 // out which library 'addr' really belongs to. This workaround can be 1552 // removed once the minimum requirement for glibc is moved to 2.3.x. 1553 data.addr = addr; 1554 data.fname = buf; 1555 data.buflen = buflen; 1556 data.base = NULL; 1557 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); 1558 1559 if (rslt) { 1560 // buf already contains library name 1561 if (offset) *offset = addr - data.base; 1562 return true; 1563 } 1564 if (dladdr((void*)addr, &dlinfo) != 0) { 1565 if (dlinfo.dli_fname != NULL) { 1566 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1567 } 1568 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1569 *offset = addr - (address)dlinfo.dli_fbase; 1570 } 1571 return true; 1572 } 1573 1574 buf[0] = '\0'; 1575 if (offset) *offset = -1; 1576 return false; 1577 } 1578 1579 // Loads .dll/.so and 1580 // in case of error it checks if .dll/.so was built for the 1581 // same architecture as Hotspot is running on 1582 1583 1584 // Remember the stack's state. The Linux dynamic linker will change 1585 // the stack to 'executable' at most once, so we must safepoint only once. 1586 bool os::Linux::_stack_is_executable = false; 1587 1588 // VM operation that loads a library. This is necessary if stack protection 1589 // of the Java stacks can be lost during loading the library. If we 1590 // do not stop the Java threads, they can stack overflow before the stacks 1591 // are protected again. 1592 class VM_LinuxDllLoad: public VM_Operation { 1593 private: 1594 const char *_filename; 1595 char *_ebuf; 1596 int _ebuflen; 1597 void *_lib; 1598 public: 1599 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) : 1600 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {} 1601 VMOp_Type type() const { return VMOp_LinuxDllLoad; } 1602 void doit() { 1603 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen); 1604 os::Linux::_stack_is_executable = true; 1605 } 1606 void* loaded_library() { return _lib; } 1607 }; 1608 1609 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1610 void * result = NULL; 1611 bool load_attempted = false; 1612 1613 // Check whether the library to load might change execution rights 1614 // of the stack. If they are changed, the protection of the stack 1615 // guard pages will be lost. We need a safepoint to fix this. 1616 // 1617 // See Linux man page execstack(8) for more info. 1618 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) { 1619 if (!ElfFile::specifies_noexecstack(filename)) { 1620 if (!is_init_completed()) { 1621 os::Linux::_stack_is_executable = true; 1622 // This is OK - No Java threads have been created yet, and hence no 1623 // stack guard pages to fix. 1624 // 1625 // This should happen only when you are building JDK7 using a very 1626 // old version of JDK6 (e.g., with JPRT) and running test_gamma. 1627 // 1628 // Dynamic loader will make all stacks executable after 1629 // this function returns, and will not do that again. 1630 assert(Threads::number_of_threads() == 0, "no Java threads should exist yet."); 1631 } else { 1632 warning("You have loaded library %s which might have disabled stack guard. " 1633 "The VM will try to fix the stack guard now.\n" 1634 "It's highly recommended that you fix the library with " 1635 "'execstack -c <libfile>', or link it with '-z noexecstack'.", 1636 filename); 1637 1638 assert(Thread::current()->is_Java_thread(), "must be Java thread"); 1639 JavaThread *jt = JavaThread::current(); 1640 if (jt->thread_state() != _thread_in_native) { 1641 // This happens when a compiler thread tries to load a hsdis-<arch>.so file 1642 // that requires ExecStack. Cannot enter safe point. Let's give up. 1643 warning("Unable to fix stack guard. Giving up."); 1644 } else { 1645 if (!LoadExecStackDllInVMThread) { 1646 // This is for the case where the DLL has an static 1647 // constructor function that executes JNI code. We cannot 1648 // load such DLLs in the VMThread. 1649 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1650 } 1651 1652 ThreadInVMfromNative tiv(jt); 1653 debug_only(VMNativeEntryWrapper vew;) 1654 1655 VM_LinuxDllLoad op(filename, ebuf, ebuflen); 1656 VMThread::execute(&op); 1657 if (LoadExecStackDllInVMThread) { 1658 result = op.loaded_library(); 1659 } 1660 load_attempted = true; 1661 } 1662 } 1663 } 1664 } 1665 1666 if (!load_attempted) { 1667 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1668 } 1669 1670 if (result != NULL) { 1671 // Successful loading 1672 return result; 1673 } 1674 1675 Elf32_Ehdr elf_head; 1676 int diag_msg_max_length=ebuflen-strlen(ebuf); 1677 char* diag_msg_buf=ebuf+strlen(ebuf); 1678 1679 if (diag_msg_max_length==0) { 1680 // No more space in ebuf for additional diagnostics message 1681 return NULL; 1682 } 1683 1684 1685 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1686 1687 if (file_descriptor < 0) { 1688 // Can't open library, report dlerror() message 1689 return NULL; 1690 } 1691 1692 bool failed_to_read_elf_head= 1693 (sizeof(elf_head)!= 1694 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1695 1696 ::close(file_descriptor); 1697 if (failed_to_read_elf_head) { 1698 // file i/o error - report dlerror() msg 1699 return NULL; 1700 } 1701 1702 typedef struct { 1703 Elf32_Half code; // Actual value as defined in elf.h 1704 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1705 unsigned char elf_class; // 32 or 64 bit 1706 unsigned char endianess; // MSB or LSB 1707 char* name; // String representation 1708 } arch_t; 1709 1710 #ifndef EM_486 1711 #define EM_486 6 /* Intel 80486 */ 1712 #endif 1713 #ifndef EM_AARCH64 1714 #define EM_AARCH64 183 /* ARM AARCH64 */ 1715 #endif 1716 1717 static const arch_t arch_array[]={ 1718 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1719 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1720 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1721 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1722 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1723 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1724 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1725 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1726 #if defined(VM_LITTLE_ENDIAN) 1727 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"}, 1728 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"}, 1729 #else 1730 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1731 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"}, 1732 #endif 1733 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1734 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1735 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1736 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1737 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1738 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1739 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}, 1740 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"}, 1741 }; 1742 1743 #if (defined IA32) 1744 static Elf32_Half running_arch_code=EM_386; 1745 #elif (defined AMD64) 1746 static Elf32_Half running_arch_code=EM_X86_64; 1747 #elif (defined IA64) 1748 static Elf32_Half running_arch_code=EM_IA_64; 1749 #elif (defined __sparc) && (defined _LP64) 1750 static Elf32_Half running_arch_code=EM_SPARCV9; 1751 #elif (defined __sparc) && (!defined _LP64) 1752 static Elf32_Half running_arch_code=EM_SPARC; 1753 #elif (defined __powerpc64__) 1754 static Elf32_Half running_arch_code=EM_PPC64; 1755 #elif (defined __powerpc__) 1756 static Elf32_Half running_arch_code=EM_PPC; 1757 #elif (defined AARCH64) 1758 static Elf32_Half running_arch_code=EM_AARCH64; 1759 #elif (defined ARM) 1760 static Elf32_Half running_arch_code=EM_ARM; 1761 #elif (defined S390) 1762 static Elf32_Half running_arch_code=EM_S390; 1763 #elif (defined ALPHA) 1764 static Elf32_Half running_arch_code=EM_ALPHA; 1765 #elif (defined MIPSEL) 1766 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1767 #elif (defined PARISC) 1768 static Elf32_Half running_arch_code=EM_PARISC; 1769 #elif (defined MIPS) 1770 static Elf32_Half running_arch_code=EM_MIPS; 1771 #elif (defined M68K) 1772 static Elf32_Half running_arch_code=EM_68K; 1773 #elif (defined SH) 1774 static Elf32_Half running_arch_code=EM_SH; 1775 #else 1776 #error Method os::dll_load requires that one of following is defined:\ 1777 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc 1778 #endif 1779 1780 // Identify compatability class for VM's architecture and library's architecture 1781 // Obtain string descriptions for architectures 1782 1783 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1784 int running_arch_index=-1; 1785 1786 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1787 if (running_arch_code == arch_array[i].code) { 1788 running_arch_index = i; 1789 } 1790 if (lib_arch.code == arch_array[i].code) { 1791 lib_arch.compat_class = arch_array[i].compat_class; 1792 lib_arch.name = arch_array[i].name; 1793 } 1794 } 1795 1796 assert(running_arch_index != -1, 1797 "Didn't find running architecture code (running_arch_code) in arch_array"); 1798 if (running_arch_index == -1) { 1799 // Even though running architecture detection failed 1800 // we may still continue with reporting dlerror() message 1801 return NULL; 1802 } 1803 1804 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1805 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1806 return NULL; 1807 } 1808 1809 #ifndef S390 1810 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1811 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1812 return NULL; 1813 } 1814 #endif // !S390 1815 1816 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1817 if (lib_arch.name!=NULL) { 1818 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1819 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1820 lib_arch.name, arch_array[running_arch_index].name); 1821 } else { 1822 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1823 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1824 lib_arch.code, 1825 arch_array[running_arch_index].name); 1826 } 1827 } 1828 1829 return NULL; 1830 } 1831 1832 void * os::Linux::dlopen_helper(const char *filename, char *ebuf, 1833 int ebuflen) { 1834 void * result = ::dlopen(filename, RTLD_LAZY); 1835 if (result == NULL) { 1836 ::strncpy(ebuf, ::dlerror(), ebuflen - 1); 1837 ebuf[ebuflen-1] = '\0'; 1838 } 1839 return result; 1840 } 1841 1842 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf, 1843 int ebuflen) { 1844 void * result = NULL; 1845 if (LoadExecStackDllInVMThread) { 1846 result = dlopen_helper(filename, ebuf, ebuflen); 1847 } 1848 1849 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a 1850 // library that requires an executable stack, or which does not have this 1851 // stack attribute set, dlopen changes the stack attribute to executable. The 1852 // read protection of the guard pages gets lost. 1853 // 1854 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad 1855 // may have been queued at the same time. 1856 1857 if (!_stack_is_executable) { 1858 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) { 1859 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized 1860 jt->stack_guards_enabled()) { // No pending stack overflow exceptions 1861 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) { 1862 warning("Attempt to reguard stack yellow zone failed."); 1863 } 1864 } 1865 } 1866 } 1867 1868 return result; 1869 } 1870 1871 void* os::dll_lookup(void* handle, const char* name) { 1872 void* res = dlsym(handle, name); 1873 return res; 1874 } 1875 1876 void* os::get_default_process_handle() { 1877 return (void*)::dlopen(NULL, RTLD_LAZY); 1878 } 1879 1880 static bool _print_ascii_file(const char* filename, outputStream* st) { 1881 int fd = ::open(filename, O_RDONLY); 1882 if (fd == -1) { 1883 return false; 1884 } 1885 1886 char buf[33]; 1887 int bytes; 1888 buf[32] = '\0'; 1889 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) { 1890 st->print_raw(buf, bytes); 1891 } 1892 1893 ::close(fd); 1894 1895 return true; 1896 } 1897 1898 void os::print_dll_info(outputStream *st) { 1899 st->print_cr("Dynamic libraries:"); 1900 1901 char fname[32]; 1902 pid_t pid = os::Linux::gettid(); 1903 1904 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); 1905 1906 if (!_print_ascii_file(fname, st)) { 1907 st->print("Can not get library information for pid = %d\n", pid); 1908 } 1909 } 1910 1911 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1912 FILE *procmapsFile = NULL; 1913 1914 // Open the procfs maps file for the current process 1915 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) { 1916 // Allocate PATH_MAX for file name plus a reasonable size for other fields. 1917 char line[PATH_MAX + 100]; 1918 1919 // Read line by line from 'file' 1920 while (fgets(line, sizeof(line), procmapsFile) != NULL) { 1921 u8 base, top, offset, inode; 1922 char permissions[5]; 1923 char device[6]; 1924 char name[PATH_MAX + 1]; 1925 1926 // Parse fields from line 1927 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s", 1928 &base, &top, permissions, &offset, device, &inode, name); 1929 1930 // Filter by device id '00:00' so that we only get file system mapped files. 1931 if (strcmp(device, "00:00") != 0) { 1932 1933 // Call callback with the fields of interest 1934 if(callback(name, (address)base, (address)top, param)) { 1935 // Oops abort, callback aborted 1936 fclose(procmapsFile); 1937 return 1; 1938 } 1939 } 1940 } 1941 fclose(procmapsFile); 1942 } 1943 return 0; 1944 } 1945 1946 void os::print_os_info_brief(outputStream* st) { 1947 os::Linux::print_distro_info(st); 1948 1949 os::Posix::print_uname_info(st); 1950 1951 os::Linux::print_libversion_info(st); 1952 1953 } 1954 1955 void os::print_os_info(outputStream* st) { 1956 st->print("OS:"); 1957 1958 os::Linux::print_distro_info(st); 1959 1960 os::Posix::print_uname_info(st); 1961 1962 // Print warning if unsafe chroot environment detected 1963 if (unsafe_chroot_detected) { 1964 st->print("WARNING!! "); 1965 st->print_cr("%s", unstable_chroot_error); 1966 } 1967 1968 os::Linux::print_libversion_info(st); 1969 1970 os::Posix::print_rlimit_info(st); 1971 1972 os::Posix::print_load_average(st); 1973 1974 os::Linux::print_full_memory_info(st); 1975 1976 os::Linux::print_proc_sys_info(st); 1977 1978 os::Linux::print_container_info(st); 1979 } 1980 1981 // Try to identify popular distros. 1982 // Most Linux distributions have a /etc/XXX-release file, which contains 1983 // the OS version string. Newer Linux distributions have a /etc/lsb-release 1984 // file that also contains the OS version string. Some have more than one 1985 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and 1986 // /etc/redhat-release.), so the order is important. 1987 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have 1988 // their own specific XXX-release file as well as a redhat-release file. 1989 // Because of this the XXX-release file needs to be searched for before the 1990 // redhat-release file. 1991 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the 1992 // search for redhat-release / SuSE-release needs to be before lsb-release. 1993 // Since the lsb-release file is the new standard it needs to be searched 1994 // before the older style release files. 1995 // Searching system-release (Red Hat) and os-release (other Linuxes) are a 1996 // next to last resort. The os-release file is a new standard that contains 1997 // distribution information and the system-release file seems to be an old 1998 // standard that has been replaced by the lsb-release and os-release files. 1999 // Searching for the debian_version file is the last resort. It contains 2000 // an informative string like "6.0.6" or "wheezy/sid". Because of this 2001 // "Debian " is printed before the contents of the debian_version file. 2002 2003 const char* distro_files[] = { 2004 "/etc/oracle-release", 2005 "/etc/mandriva-release", 2006 "/etc/mandrake-release", 2007 "/etc/sun-release", 2008 "/etc/redhat-release", 2009 "/etc/SuSE-release", 2010 "/etc/lsb-release", 2011 "/etc/turbolinux-release", 2012 "/etc/gentoo-release", 2013 "/etc/ltib-release", 2014 "/etc/angstrom-version", 2015 "/etc/system-release", 2016 "/etc/os-release", 2017 NULL }; 2018 2019 void os::Linux::print_distro_info(outputStream* st) { 2020 for (int i = 0;; i++) { 2021 const char* file = distro_files[i]; 2022 if (file == NULL) { 2023 break; // done 2024 } 2025 // If file prints, we found it. 2026 if (_print_ascii_file(file, st)) { 2027 return; 2028 } 2029 } 2030 2031 if (file_exists("/etc/debian_version")) { 2032 st->print("Debian "); 2033 _print_ascii_file("/etc/debian_version", st); 2034 } else { 2035 st->print("Linux"); 2036 } 2037 st->cr(); 2038 } 2039 2040 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) { 2041 char buf[256]; 2042 while (fgets(buf, sizeof(buf), fp)) { 2043 // Edit out extra stuff in expected format 2044 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) { 2045 char* ptr = strstr(buf, "\""); // the name is in quotes 2046 if (ptr != NULL) { 2047 ptr++; // go beyond first quote 2048 char* nl = strchr(ptr, '\"'); 2049 if (nl != NULL) *nl = '\0'; 2050 strncpy(distro, ptr, length); 2051 } else { 2052 ptr = strstr(buf, "="); 2053 ptr++; // go beyond equals then 2054 char* nl = strchr(ptr, '\n'); 2055 if (nl != NULL) *nl = '\0'; 2056 strncpy(distro, ptr, length); 2057 } 2058 return; 2059 } else if (get_first_line) { 2060 char* nl = strchr(buf, '\n'); 2061 if (nl != NULL) *nl = '\0'; 2062 strncpy(distro, buf, length); 2063 return; 2064 } 2065 } 2066 // print last line and close 2067 char* nl = strchr(buf, '\n'); 2068 if (nl != NULL) *nl = '\0'; 2069 strncpy(distro, buf, length); 2070 } 2071 2072 static void parse_os_info(char* distro, size_t length, const char* file) { 2073 FILE* fp = fopen(file, "r"); 2074 if (fp != NULL) { 2075 // if suse format, print out first line 2076 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0); 2077 parse_os_info_helper(fp, distro, length, get_first_line); 2078 fclose(fp); 2079 } 2080 } 2081 2082 void os::get_summary_os_info(char* buf, size_t buflen) { 2083 for (int i = 0;; i++) { 2084 const char* file = distro_files[i]; 2085 if (file == NULL) { 2086 break; // ran out of distro_files 2087 } 2088 if (file_exists(file)) { 2089 parse_os_info(buf, buflen, file); 2090 return; 2091 } 2092 } 2093 // special case for debian 2094 if (file_exists("/etc/debian_version")) { 2095 strncpy(buf, "Debian ", buflen); 2096 if (buflen > 7) { 2097 parse_os_info(&buf[7], buflen-7, "/etc/debian_version"); 2098 } 2099 } else { 2100 strncpy(buf, "Linux", buflen); 2101 } 2102 } 2103 2104 void os::Linux::print_libversion_info(outputStream* st) { 2105 // libc, pthread 2106 st->print("libc:"); 2107 st->print("%s ", os::Linux::glibc_version()); 2108 st->print("%s ", os::Linux::libpthread_version()); 2109 st->cr(); 2110 } 2111 2112 void os::Linux::print_proc_sys_info(outputStream* st) { 2113 st->cr(); 2114 st->print_cr("/proc/sys/kernel/threads-max (system-wide limit on the number of threads):"); 2115 _print_ascii_file("/proc/sys/kernel/threads-max", st); 2116 st->cr(); 2117 st->cr(); 2118 2119 st->print_cr("/proc/sys/vm/max_map_count (maximum number of memory map areas a process may have):"); 2120 _print_ascii_file("/proc/sys/vm/max_map_count", st); 2121 st->cr(); 2122 st->cr(); 2123 2124 st->print_cr("/proc/sys/kernel/pid_max (system-wide limit on number of process identifiers):"); 2125 _print_ascii_file("/proc/sys/kernel/pid_max", st); 2126 st->cr(); 2127 st->cr(); 2128 } 2129 2130 void os::Linux::print_full_memory_info(outputStream* st) { 2131 st->print("\n/proc/meminfo:\n"); 2132 _print_ascii_file("/proc/meminfo", st); 2133 st->cr(); 2134 } 2135 2136 void os::Linux::print_container_info(outputStream* st) { 2137 if (!OSContainer::is_containerized()) { 2138 return; 2139 } 2140 2141 st->print("container (cgroup) information:\n"); 2142 2143 const char *p_ct = OSContainer::container_type(); 2144 st->print("container_type: %s\n", p_ct != NULL ? p_ct : "failed"); 2145 2146 char *p = OSContainer::cpu_cpuset_cpus(); 2147 st->print("cpu_cpuset_cpus: %s\n", p != NULL ? p : "failed"); 2148 free(p); 2149 2150 p = OSContainer::cpu_cpuset_memory_nodes(); 2151 st->print("cpu_memory_nodes: %s\n", p != NULL ? p : "failed"); 2152 free(p); 2153 2154 int i = OSContainer::active_processor_count(); 2155 if (i > 0) { 2156 st->print("active_processor_count: %d\n", i); 2157 } else { 2158 st->print("active_processor_count: failed\n"); 2159 } 2160 2161 i = OSContainer::cpu_quota(); 2162 st->print("cpu_quota: %d\n", i); 2163 2164 i = OSContainer::cpu_period(); 2165 st->print("cpu_period: %d\n", i); 2166 2167 i = OSContainer::cpu_shares(); 2168 st->print("cpu_shares: %d\n", i); 2169 2170 jlong j = OSContainer::memory_limit_in_bytes(); 2171 st->print("memory_limit_in_bytes: " JLONG_FORMAT "\n", j); 2172 2173 j = OSContainer::memory_and_swap_limit_in_bytes(); 2174 st->print("memory_and_swap_limit_in_bytes: " JLONG_FORMAT "\n", j); 2175 2176 j = OSContainer::memory_soft_limit_in_bytes(); 2177 st->print("memory_soft_limit_in_bytes: " JLONG_FORMAT "\n", j); 2178 2179 j = OSContainer::OSContainer::memory_usage_in_bytes(); 2180 st->print("memory_usage_in_bytes: " JLONG_FORMAT "\n", j); 2181 2182 j = OSContainer::OSContainer::memory_max_usage_in_bytes(); 2183 st->print("memory_max_usage_in_bytes: " JLONG_FORMAT "\n", j); 2184 st->cr(); 2185 } 2186 2187 void os::print_memory_info(outputStream* st) { 2188 2189 st->print("Memory:"); 2190 st->print(" %dk page", os::vm_page_size()>>10); 2191 2192 // values in struct sysinfo are "unsigned long" 2193 struct sysinfo si; 2194 sysinfo(&si); 2195 2196 st->print(", physical " UINT64_FORMAT "k", 2197 os::physical_memory() >> 10); 2198 st->print("(" UINT64_FORMAT "k free)", 2199 os::available_memory() >> 10); 2200 st->print(", swap " UINT64_FORMAT "k", 2201 ((jlong)si.totalswap * si.mem_unit) >> 10); 2202 st->print("(" UINT64_FORMAT "k free)", 2203 ((jlong)si.freeswap * si.mem_unit) >> 10); 2204 st->cr(); 2205 } 2206 2207 // Print the first "model name" line and the first "flags" line 2208 // that we find and nothing more. We assume "model name" comes 2209 // before "flags" so if we find a second "model name", then the 2210 // "flags" field is considered missing. 2211 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) { 2212 #if defined(IA32) || defined(AMD64) 2213 // Other platforms have less repetitive cpuinfo files 2214 FILE *fp = fopen("/proc/cpuinfo", "r"); 2215 if (fp) { 2216 while (!feof(fp)) { 2217 if (fgets(buf, buflen, fp)) { 2218 // Assume model name comes before flags 2219 bool model_name_printed = false; 2220 if (strstr(buf, "model name") != NULL) { 2221 if (!model_name_printed) { 2222 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n"); 2223 st->print_raw(buf); 2224 model_name_printed = true; 2225 } else { 2226 // model name printed but not flags? Odd, just return 2227 fclose(fp); 2228 return true; 2229 } 2230 } 2231 // print the flags line too 2232 if (strstr(buf, "flags") != NULL) { 2233 st->print_raw(buf); 2234 fclose(fp); 2235 return true; 2236 } 2237 } 2238 } 2239 fclose(fp); 2240 } 2241 #endif // x86 platforms 2242 return false; 2243 } 2244 2245 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) { 2246 // Only print the model name if the platform provides this as a summary 2247 if (!print_model_name_and_flags(st, buf, buflen)) { 2248 st->print("\n/proc/cpuinfo:\n"); 2249 if (!_print_ascii_file("/proc/cpuinfo", st)) { 2250 st->print_cr(" <Not Available>"); 2251 } 2252 } 2253 } 2254 2255 #if defined(AMD64) || defined(IA32) || defined(X32) 2256 const char* search_string = "model name"; 2257 #elif defined(M68K) 2258 const char* search_string = "CPU"; 2259 #elif defined(PPC64) 2260 const char* search_string = "cpu"; 2261 #elif defined(S390) 2262 const char* search_string = "processor"; 2263 #elif defined(SPARC) 2264 const char* search_string = "cpu"; 2265 #else 2266 const char* search_string = "Processor"; 2267 #endif 2268 2269 // Parses the cpuinfo file for string representing the model name. 2270 void os::get_summary_cpu_info(char* cpuinfo, size_t length) { 2271 FILE* fp = fopen("/proc/cpuinfo", "r"); 2272 if (fp != NULL) { 2273 while (!feof(fp)) { 2274 char buf[256]; 2275 if (fgets(buf, sizeof(buf), fp)) { 2276 char* start = strstr(buf, search_string); 2277 if (start != NULL) { 2278 char *ptr = start + strlen(search_string); 2279 char *end = buf + strlen(buf); 2280 while (ptr != end) { 2281 // skip whitespace and colon for the rest of the name. 2282 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') { 2283 break; 2284 } 2285 ptr++; 2286 } 2287 if (ptr != end) { 2288 // reasonable string, get rid of newline and keep the rest 2289 char* nl = strchr(buf, '\n'); 2290 if (nl != NULL) *nl = '\0'; 2291 strncpy(cpuinfo, ptr, length); 2292 fclose(fp); 2293 return; 2294 } 2295 } 2296 } 2297 } 2298 fclose(fp); 2299 } 2300 // cpuinfo not found or parsing failed, just print generic string. The entire 2301 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86) 2302 #if defined(AARCH64) 2303 strncpy(cpuinfo, "AArch64", length); 2304 #elif defined(AMD64) 2305 strncpy(cpuinfo, "x86_64", length); 2306 #elif defined(ARM) // Order wrt. AARCH64 is relevant! 2307 strncpy(cpuinfo, "ARM", length); 2308 #elif defined(IA32) 2309 strncpy(cpuinfo, "x86_32", length); 2310 #elif defined(IA64) 2311 strncpy(cpuinfo, "IA64", length); 2312 #elif defined(PPC) 2313 strncpy(cpuinfo, "PPC64", length); 2314 #elif defined(S390) 2315 strncpy(cpuinfo, "S390", length); 2316 #elif defined(SPARC) 2317 strncpy(cpuinfo, "sparcv9", length); 2318 #elif defined(ZERO_LIBARCH) 2319 strncpy(cpuinfo, ZERO_LIBARCH, length); 2320 #else 2321 strncpy(cpuinfo, "unknown", length); 2322 #endif 2323 } 2324 2325 static void print_signal_handler(outputStream* st, int sig, 2326 char* buf, size_t buflen); 2327 2328 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 2329 st->print_cr("Signal Handlers:"); 2330 print_signal_handler(st, SIGSEGV, buf, buflen); 2331 print_signal_handler(st, SIGBUS , buf, buflen); 2332 print_signal_handler(st, SIGFPE , buf, buflen); 2333 print_signal_handler(st, SIGPIPE, buf, buflen); 2334 print_signal_handler(st, SIGXFSZ, buf, buflen); 2335 print_signal_handler(st, SIGILL , buf, buflen); 2336 print_signal_handler(st, SR_signum, buf, buflen); 2337 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 2338 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 2339 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 2340 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 2341 #if defined(PPC64) 2342 print_signal_handler(st, SIGTRAP, buf, buflen); 2343 #endif 2344 } 2345 2346 static char saved_jvm_path[MAXPATHLEN] = {0}; 2347 2348 // Find the full path to the current module, libjvm.so 2349 void os::jvm_path(char *buf, jint buflen) { 2350 // Error checking. 2351 if (buflen < MAXPATHLEN) { 2352 assert(false, "must use a large-enough buffer"); 2353 buf[0] = '\0'; 2354 return; 2355 } 2356 // Lazy resolve the path to current module. 2357 if (saved_jvm_path[0] != 0) { 2358 strcpy(buf, saved_jvm_path); 2359 return; 2360 } 2361 2362 char dli_fname[MAXPATHLEN]; 2363 bool ret = dll_address_to_library_name( 2364 CAST_FROM_FN_PTR(address, os::jvm_path), 2365 dli_fname, sizeof(dli_fname), NULL); 2366 assert(ret, "cannot locate libjvm"); 2367 char *rp = NULL; 2368 if (ret && dli_fname[0] != '\0') { 2369 rp = os::Posix::realpath(dli_fname, buf, buflen); 2370 } 2371 if (rp == NULL) { 2372 return; 2373 } 2374 2375 if (Arguments::sun_java_launcher_is_altjvm()) { 2376 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 2377 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so". 2378 // If "/jre/lib/" appears at the right place in the string, then 2379 // assume we are installed in a JDK and we're done. Otherwise, check 2380 // for a JAVA_HOME environment variable and fix up the path so it 2381 // looks like libjvm.so is installed there (append a fake suffix 2382 // hotspot/libjvm.so). 2383 const char *p = buf + strlen(buf) - 1; 2384 for (int count = 0; p > buf && count < 5; ++count) { 2385 for (--p; p > buf && *p != '/'; --p) 2386 /* empty */ ; 2387 } 2388 2389 if (strncmp(p, "/jre/lib/", 9) != 0) { 2390 // Look for JAVA_HOME in the environment. 2391 char* java_home_var = ::getenv("JAVA_HOME"); 2392 if (java_home_var != NULL && java_home_var[0] != 0) { 2393 char* jrelib_p; 2394 int len; 2395 2396 // Check the current module name "libjvm.so". 2397 p = strrchr(buf, '/'); 2398 if (p == NULL) { 2399 return; 2400 } 2401 assert(strstr(p, "/libjvm") == p, "invalid library name"); 2402 2403 rp = os::Posix::realpath(java_home_var, buf, buflen); 2404 if (rp == NULL) { 2405 return; 2406 } 2407 2408 // determine if this is a legacy image or modules image 2409 // modules image doesn't have "jre" subdirectory 2410 len = strlen(buf); 2411 assert(len < buflen, "Ran out of buffer room"); 2412 jrelib_p = buf + len; 2413 snprintf(jrelib_p, buflen-len, "/jre/lib"); 2414 if (0 != access(buf, F_OK)) { 2415 snprintf(jrelib_p, buflen-len, "/lib"); 2416 } 2417 2418 if (0 == access(buf, F_OK)) { 2419 // Use current module name "libjvm.so" 2420 len = strlen(buf); 2421 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so"); 2422 } else { 2423 // Go back to path of .so 2424 rp = os::Posix::realpath(dli_fname, buf, buflen); 2425 if (rp == NULL) { 2426 return; 2427 } 2428 } 2429 } 2430 } 2431 } 2432 2433 strncpy(saved_jvm_path, buf, MAXPATHLEN); 2434 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 2435 } 2436 2437 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 2438 // no prefix required, not even "_" 2439 } 2440 2441 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 2442 // no suffix required 2443 } 2444 2445 //////////////////////////////////////////////////////////////////////////////// 2446 // sun.misc.Signal support 2447 2448 static volatile jint sigint_count = 0; 2449 2450 static void UserHandler(int sig, void *siginfo, void *context) { 2451 // 4511530 - sem_post is serialized and handled by the manager thread. When 2452 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 2453 // don't want to flood the manager thread with sem_post requests. 2454 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 2455 return; 2456 } 2457 2458 // Ctrl-C is pressed during error reporting, likely because the error 2459 // handler fails to abort. Let VM die immediately. 2460 if (sig == SIGINT && VMError::is_error_reported()) { 2461 os::die(); 2462 } 2463 2464 os::signal_notify(sig); 2465 } 2466 2467 void* os::user_handler() { 2468 return CAST_FROM_FN_PTR(void*, UserHandler); 2469 } 2470 2471 static struct timespec create_semaphore_timespec(unsigned int sec, int nsec) { 2472 struct timespec ts; 2473 // Semaphore's are always associated with CLOCK_REALTIME 2474 os::Linux::clock_gettime(CLOCK_REALTIME, &ts); 2475 // see os_posix.cpp for discussion on overflow checking 2476 if (sec >= MAX_SECS) { 2477 ts.tv_sec += MAX_SECS; 2478 ts.tv_nsec = 0; 2479 } else { 2480 ts.tv_sec += sec; 2481 ts.tv_nsec += nsec; 2482 if (ts.tv_nsec >= NANOSECS_PER_SEC) { 2483 ts.tv_nsec -= NANOSECS_PER_SEC; 2484 ++ts.tv_sec; // note: this must be <= max_secs 2485 } 2486 } 2487 2488 return ts; 2489 } 2490 2491 extern "C" { 2492 typedef void (*sa_handler_t)(int); 2493 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 2494 } 2495 2496 void* os::signal(int signal_number, void* handler) { 2497 struct sigaction sigAct, oldSigAct; 2498 2499 sigfillset(&(sigAct.sa_mask)); 2500 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 2501 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 2502 2503 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 2504 // -1 means registration failed 2505 return (void *)-1; 2506 } 2507 2508 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 2509 } 2510 2511 void os::signal_raise(int signal_number) { 2512 ::raise(signal_number); 2513 } 2514 2515 // The following code is moved from os.cpp for making this 2516 // code platform specific, which it is by its very nature. 2517 2518 // Will be modified when max signal is changed to be dynamic 2519 int os::sigexitnum_pd() { 2520 return NSIG; 2521 } 2522 2523 // a counter for each possible signal value 2524 static volatile jint pending_signals[NSIG+1] = { 0 }; 2525 2526 // Linux(POSIX) specific hand shaking semaphore. 2527 static Semaphore* sig_sem = NULL; 2528 static PosixSemaphore sr_semaphore; 2529 2530 static void jdk_misc_signal_init() { 2531 // Initialize signal structures 2532 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2533 2534 // Initialize signal semaphore 2535 sig_sem = new Semaphore(); 2536 } 2537 2538 void os::signal_notify(int sig) { 2539 if (sig_sem != NULL) { 2540 Atomic::inc(&pending_signals[sig]); 2541 sig_sem->signal(); 2542 } else { 2543 // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init 2544 // initialization isn't called. 2545 assert(ReduceSignalUsage, "signal semaphore should be created"); 2546 } 2547 } 2548 2549 static int check_pending_signals() { 2550 Atomic::store(0, &sigint_count); 2551 for (;;) { 2552 for (int i = 0; i < NSIG + 1; i++) { 2553 jint n = pending_signals[i]; 2554 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2555 return i; 2556 } 2557 } 2558 JavaThread *thread = JavaThread::current(); 2559 ThreadBlockInVM tbivm(thread); 2560 2561 bool threadIsSuspended; 2562 do { 2563 thread->set_suspend_equivalent(); 2564 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2565 sig_sem->wait(); 2566 2567 // were we externally suspended while we were waiting? 2568 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2569 if (threadIsSuspended) { 2570 // The semaphore has been incremented, but while we were waiting 2571 // another thread suspended us. We don't want to continue running 2572 // while suspended because that would surprise the thread that 2573 // suspended us. 2574 sig_sem->signal(); 2575 2576 thread->java_suspend_self(); 2577 } 2578 } while (threadIsSuspended); 2579 } 2580 } 2581 2582 int os::signal_wait() { 2583 return check_pending_signals(); 2584 } 2585 2586 //////////////////////////////////////////////////////////////////////////////// 2587 // Virtual Memory 2588 2589 int os::vm_page_size() { 2590 // Seems redundant as all get out 2591 assert(os::Linux::page_size() != -1, "must call os::init"); 2592 return os::Linux::page_size(); 2593 } 2594 2595 // Solaris allocates memory by pages. 2596 int os::vm_allocation_granularity() { 2597 assert(os::Linux::page_size() != -1, "must call os::init"); 2598 return os::Linux::page_size(); 2599 } 2600 2601 // Rationale behind this function: 2602 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2603 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2604 // samples for JITted code. Here we create private executable mapping over the code cache 2605 // and then we can use standard (well, almost, as mapping can change) way to provide 2606 // info for the reporting script by storing timestamp and location of symbol 2607 void linux_wrap_code(char* base, size_t size) { 2608 static volatile jint cnt = 0; 2609 2610 if (!UseOprofile) { 2611 return; 2612 } 2613 2614 char buf[PATH_MAX+1]; 2615 int num = Atomic::add(1, &cnt); 2616 2617 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d", 2618 os::get_temp_directory(), os::current_process_id(), num); 2619 unlink(buf); 2620 2621 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2622 2623 if (fd != -1) { 2624 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2625 if (rv != (off_t)-1) { 2626 if (::write(fd, "", 1) == 1) { 2627 mmap(base, size, 2628 PROT_READ|PROT_WRITE|PROT_EXEC, 2629 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2630 } 2631 } 2632 ::close(fd); 2633 unlink(buf); 2634 } 2635 } 2636 2637 static bool recoverable_mmap_error(int err) { 2638 // See if the error is one we can let the caller handle. This 2639 // list of errno values comes from JBS-6843484. I can't find a 2640 // Linux man page that documents this specific set of errno 2641 // values so while this list currently matches Solaris, it may 2642 // change as we gain experience with this failure mode. 2643 switch (err) { 2644 case EBADF: 2645 case EINVAL: 2646 case ENOTSUP: 2647 // let the caller deal with these errors 2648 return true; 2649 2650 default: 2651 // Any remaining errors on this OS can cause our reserved mapping 2652 // to be lost. That can cause confusion where different data 2653 // structures think they have the same memory mapped. The worst 2654 // scenario is if both the VM and a library think they have the 2655 // same memory mapped. 2656 return false; 2657 } 2658 } 2659 2660 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2661 int err) { 2662 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2663 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec, 2664 os::strerror(err), err); 2665 } 2666 2667 static void warn_fail_commit_memory(char* addr, size_t size, 2668 size_t alignment_hint, bool exec, 2669 int err) { 2670 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2671 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, 2672 alignment_hint, exec, os::strerror(err), err); 2673 } 2674 2675 // NOTE: Linux kernel does not really reserve the pages for us. 2676 // All it does is to check if there are enough free pages 2677 // left at the time of mmap(). This could be a potential 2678 // problem. 2679 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) { 2680 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2681 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2682 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2683 if (res != (uintptr_t) MAP_FAILED) { 2684 if (UseNUMAInterleaving) { 2685 numa_make_global(addr, size); 2686 } 2687 return 0; 2688 } 2689 2690 int err = errno; // save errno from mmap() call above 2691 2692 if (!recoverable_mmap_error(err)) { 2693 warn_fail_commit_memory(addr, size, exec, err); 2694 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory."); 2695 } 2696 2697 return err; 2698 } 2699 2700 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2701 return os::Linux::commit_memory_impl(addr, size, exec) == 0; 2702 } 2703 2704 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2705 const char* mesg) { 2706 assert(mesg != NULL, "mesg must be specified"); 2707 int err = os::Linux::commit_memory_impl(addr, size, exec); 2708 if (err != 0) { 2709 // the caller wants all commit errors to exit with the specified mesg: 2710 warn_fail_commit_memory(addr, size, exec, err); 2711 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2712 } 2713 } 2714 2715 // Define MAP_HUGETLB here so we can build HotSpot on old systems. 2716 #ifndef MAP_HUGETLB 2717 #define MAP_HUGETLB 0x40000 2718 #endif 2719 2720 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems. 2721 #ifndef MADV_HUGEPAGE 2722 #define MADV_HUGEPAGE 14 2723 #endif 2724 2725 int os::Linux::commit_memory_impl(char* addr, size_t size, 2726 size_t alignment_hint, bool exec) { 2727 int err = os::Linux::commit_memory_impl(addr, size, exec); 2728 if (err == 0) { 2729 realign_memory(addr, size, alignment_hint); 2730 } 2731 return err; 2732 } 2733 2734 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2735 bool exec) { 2736 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0; 2737 } 2738 2739 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2740 size_t alignment_hint, bool exec, 2741 const char* mesg) { 2742 assert(mesg != NULL, "mesg must be specified"); 2743 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec); 2744 if (err != 0) { 2745 // the caller wants all commit errors to exit with the specified mesg: 2746 warn_fail_commit_memory(addr, size, alignment_hint, exec, err); 2747 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2748 } 2749 } 2750 2751 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2752 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) { 2753 // We don't check the return value: madvise(MADV_HUGEPAGE) may not 2754 // be supported or the memory may already be backed by huge pages. 2755 ::madvise(addr, bytes, MADV_HUGEPAGE); 2756 } 2757 } 2758 2759 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2760 // This method works by doing an mmap over an existing mmaping and effectively discarding 2761 // the existing pages. However it won't work for SHM-based large pages that cannot be 2762 // uncommitted at all. We don't do anything in this case to avoid creating a segment with 2763 // small pages on top of the SHM segment. This method always works for small pages, so we 2764 // allow that in any case. 2765 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) { 2766 commit_memory(addr, bytes, alignment_hint, !ExecMem); 2767 } 2768 } 2769 2770 void os::numa_make_global(char *addr, size_t bytes) { 2771 Linux::numa_interleave_memory(addr, bytes); 2772 } 2773 2774 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the 2775 // bind policy to MPOL_PREFERRED for the current thread. 2776 #define USE_MPOL_PREFERRED 0 2777 2778 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2779 // To make NUMA and large pages more robust when both enabled, we need to ease 2780 // the requirements on where the memory should be allocated. MPOL_BIND is the 2781 // default policy and it will force memory to be allocated on the specified 2782 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on 2783 // the specified node, but will not force it. Using this policy will prevent 2784 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no 2785 // free large pages. 2786 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED); 2787 Linux::numa_tonode_memory(addr, bytes, lgrp_hint); 2788 } 2789 2790 bool os::numa_topology_changed() { return false; } 2791 2792 size_t os::numa_get_groups_num() { 2793 // Return just the number of nodes in which it's possible to allocate memory 2794 // (in numa terminology, configured nodes). 2795 return Linux::numa_num_configured_nodes(); 2796 } 2797 2798 int os::numa_get_group_id() { 2799 int cpu_id = Linux::sched_getcpu(); 2800 if (cpu_id != -1) { 2801 int lgrp_id = Linux::get_node_by_cpu(cpu_id); 2802 if (lgrp_id != -1) { 2803 return lgrp_id; 2804 } 2805 } 2806 return 0; 2807 } 2808 2809 int os::Linux::get_existing_num_nodes() { 2810 int node; 2811 int highest_node_number = Linux::numa_max_node(); 2812 int num_nodes = 0; 2813 2814 // Get the total number of nodes in the system including nodes without memory. 2815 for (node = 0; node <= highest_node_number; node++) { 2816 if (isnode_in_existing_nodes(node)) { 2817 num_nodes++; 2818 } 2819 } 2820 return num_nodes; 2821 } 2822 2823 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2824 int highest_node_number = Linux::numa_max_node(); 2825 size_t i = 0; 2826 2827 // Map all node ids in which it is possible to allocate memory. Also nodes are 2828 // not always consecutively available, i.e. available from 0 to the highest 2829 // node number. If the nodes have been bound explicitly using numactl membind, 2830 // then allocate memory from those nodes only. 2831 for (int node = 0; node <= highest_node_number; node++) { 2832 if (Linux::isnode_in_bound_nodes((unsigned int)node)) { 2833 ids[i++] = node; 2834 } 2835 } 2836 return i; 2837 } 2838 2839 bool os::get_page_info(char *start, page_info* info) { 2840 return false; 2841 } 2842 2843 char *os::scan_pages(char *start, char* end, page_info* page_expected, 2844 page_info* page_found) { 2845 return end; 2846 } 2847 2848 2849 int os::Linux::sched_getcpu_syscall(void) { 2850 unsigned int cpu = 0; 2851 int retval = -1; 2852 2853 #if defined(IA32) 2854 #ifndef SYS_getcpu 2855 #define SYS_getcpu 318 2856 #endif 2857 retval = syscall(SYS_getcpu, &cpu, NULL, NULL); 2858 #elif defined(AMD64) 2859 // Unfortunately we have to bring all these macros here from vsyscall.h 2860 // to be able to compile on old linuxes. 2861 #define __NR_vgetcpu 2 2862 #define VSYSCALL_START (-10UL << 20) 2863 #define VSYSCALL_SIZE 1024 2864 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr)) 2865 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache); 2866 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu); 2867 retval = vgetcpu(&cpu, NULL, NULL); 2868 #endif 2869 2870 return (retval == -1) ? retval : cpu; 2871 } 2872 2873 void os::Linux::sched_getcpu_init() { 2874 // sched_getcpu() should be in libc. 2875 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2876 dlsym(RTLD_DEFAULT, "sched_getcpu"))); 2877 2878 // If it's not, try a direct syscall. 2879 if (sched_getcpu() == -1) { 2880 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2881 (void*)&sched_getcpu_syscall)); 2882 } 2883 2884 if (sched_getcpu() == -1) { 2885 vm_exit_during_initialization("getcpu(2) system call not supported by kernel"); 2886 } 2887 } 2888 2889 // Something to do with the numa-aware allocator needs these symbols 2890 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { } 2891 extern "C" JNIEXPORT void numa_error(char *where) { } 2892 2893 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails 2894 // load symbol from base version instead. 2895 void* os::Linux::libnuma_dlsym(void* handle, const char *name) { 2896 void *f = dlvsym(handle, name, "libnuma_1.1"); 2897 if (f == NULL) { 2898 f = dlsym(handle, name); 2899 } 2900 return f; 2901 } 2902 2903 // Handle request to load libnuma symbol version 1.2 (API v2) only. 2904 // Return NULL if the symbol is not defined in this particular version. 2905 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) { 2906 return dlvsym(handle, name, "libnuma_1.2"); 2907 } 2908 2909 bool os::Linux::libnuma_init() { 2910 if (sched_getcpu() != -1) { // Requires sched_getcpu() support 2911 void *handle = dlopen("libnuma.so.1", RTLD_LAZY); 2912 if (handle != NULL) { 2913 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, 2914 libnuma_dlsym(handle, "numa_node_to_cpus"))); 2915 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, 2916 libnuma_dlsym(handle, "numa_max_node"))); 2917 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t, 2918 libnuma_dlsym(handle, "numa_num_configured_nodes"))); 2919 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, 2920 libnuma_dlsym(handle, "numa_available"))); 2921 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, 2922 libnuma_dlsym(handle, "numa_tonode_memory"))); 2923 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t, 2924 libnuma_dlsym(handle, "numa_interleave_memory"))); 2925 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t, 2926 libnuma_v2_dlsym(handle, "numa_interleave_memory"))); 2927 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t, 2928 libnuma_dlsym(handle, "numa_set_bind_policy"))); 2929 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t, 2930 libnuma_dlsym(handle, "numa_bitmask_isbitset"))); 2931 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t, 2932 libnuma_dlsym(handle, "numa_distance"))); 2933 set_numa_get_membind(CAST_TO_FN_PTR(numa_get_membind_func_t, 2934 libnuma_v2_dlsym(handle, "numa_get_membind"))); 2935 2936 if (numa_available() != -1) { 2937 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); 2938 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr")); 2939 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr")); 2940 // Create an index -> node mapping, since nodes are not always consecutive 2941 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2942 rebuild_nindex_to_node_map(); 2943 // Create a cpu -> node mapping 2944 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2945 rebuild_cpu_to_node_map(); 2946 return true; 2947 } 2948 } 2949 } 2950 return false; 2951 } 2952 2953 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 2954 // Creating guard page is very expensive. Java thread has HotSpot 2955 // guard pages, only enable glibc guard page for non-Java threads. 2956 // (Remember: compiler thread is a Java thread, too!) 2957 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size()); 2958 } 2959 2960 void os::Linux::rebuild_nindex_to_node_map() { 2961 int highest_node_number = Linux::numa_max_node(); 2962 2963 nindex_to_node()->clear(); 2964 for (int node = 0; node <= highest_node_number; node++) { 2965 if (Linux::isnode_in_existing_nodes(node)) { 2966 nindex_to_node()->append(node); 2967 } 2968 } 2969 } 2970 2971 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. 2972 // The table is later used in get_node_by_cpu(). 2973 void os::Linux::rebuild_cpu_to_node_map() { 2974 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure 2975 // in libnuma (possible values are starting from 16, 2976 // and continuing up with every other power of 2, but less 2977 // than the maximum number of CPUs supported by kernel), and 2978 // is a subject to change (in libnuma version 2 the requirements 2979 // are more reasonable) we'll just hardcode the number they use 2980 // in the library. 2981 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT; 2982 2983 size_t cpu_num = processor_count(); 2984 size_t cpu_map_size = NCPUS / BitsPerCLong; 2985 size_t cpu_map_valid_size = 2986 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size); 2987 2988 cpu_to_node()->clear(); 2989 cpu_to_node()->at_grow(cpu_num - 1); 2990 2991 size_t node_num = get_existing_num_nodes(); 2992 2993 int distance = 0; 2994 int closest_distance = INT_MAX; 2995 int closest_node = 0; 2996 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal); 2997 for (size_t i = 0; i < node_num; i++) { 2998 // Check if node is configured (not a memory-less node). If it is not, find 2999 // the closest configured node. Check also if node is bound, i.e. it's allowed 3000 // to allocate memory from the node. If it's not allowed, map cpus in that node 3001 // to the closest node from which memory allocation is allowed. 3002 if (!isnode_in_configured_nodes(nindex_to_node()->at(i)) || 3003 !isnode_in_bound_nodes(nindex_to_node()->at(i))) { 3004 closest_distance = INT_MAX; 3005 // Check distance from all remaining nodes in the system. Ignore distance 3006 // from itself, from another non-configured node, and from another non-bound 3007 // node. 3008 for (size_t m = 0; m < node_num; m++) { 3009 if (m != i && 3010 isnode_in_configured_nodes(nindex_to_node()->at(m)) && 3011 isnode_in_bound_nodes(nindex_to_node()->at(m))) { 3012 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m)); 3013 // If a closest node is found, update. There is always at least one 3014 // configured and bound node in the system so there is always at least 3015 // one node close. 3016 if (distance != 0 && distance < closest_distance) { 3017 closest_distance = distance; 3018 closest_node = nindex_to_node()->at(m); 3019 } 3020 } 3021 } 3022 } else { 3023 // Current node is already a configured node. 3024 closest_node = nindex_to_node()->at(i); 3025 } 3026 3027 // Get cpus from the original node and map them to the closest node. If node 3028 // is a configured node (not a memory-less node), then original node and 3029 // closest node are the same. 3030 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { 3031 for (size_t j = 0; j < cpu_map_valid_size; j++) { 3032 if (cpu_map[j] != 0) { 3033 for (size_t k = 0; k < BitsPerCLong; k++) { 3034 if (cpu_map[j] & (1UL << k)) { 3035 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node); 3036 } 3037 } 3038 } 3039 } 3040 } 3041 } 3042 FREE_C_HEAP_ARRAY(unsigned long, cpu_map); 3043 } 3044 3045 int os::Linux::get_node_by_cpu(int cpu_id) { 3046 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { 3047 return cpu_to_node()->at(cpu_id); 3048 } 3049 return -1; 3050 } 3051 3052 GrowableArray<int>* os::Linux::_cpu_to_node; 3053 GrowableArray<int>* os::Linux::_nindex_to_node; 3054 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu; 3055 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus; 3056 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node; 3057 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes; 3058 os::Linux::numa_available_func_t os::Linux::_numa_available; 3059 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory; 3060 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory; 3061 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2; 3062 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy; 3063 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset; 3064 os::Linux::numa_distance_func_t os::Linux::_numa_distance; 3065 os::Linux::numa_get_membind_func_t os::Linux::_numa_get_membind; 3066 unsigned long* os::Linux::_numa_all_nodes; 3067 struct bitmask* os::Linux::_numa_all_nodes_ptr; 3068 struct bitmask* os::Linux::_numa_nodes_ptr; 3069 3070 bool os::pd_uncommit_memory(char* addr, size_t size) { 3071 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 3072 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 3073 return res != (uintptr_t) MAP_FAILED; 3074 } 3075 3076 static address get_stack_commited_bottom(address bottom, size_t size) { 3077 address nbot = bottom; 3078 address ntop = bottom + size; 3079 3080 size_t page_sz = os::vm_page_size(); 3081 unsigned pages = size / page_sz; 3082 3083 unsigned char vec[1]; 3084 unsigned imin = 1, imax = pages + 1, imid; 3085 int mincore_return_value = 0; 3086 3087 assert(imin <= imax, "Unexpected page size"); 3088 3089 while (imin < imax) { 3090 imid = (imax + imin) / 2; 3091 nbot = ntop - (imid * page_sz); 3092 3093 // Use a trick with mincore to check whether the page is mapped or not. 3094 // mincore sets vec to 1 if page resides in memory and to 0 if page 3095 // is swapped output but if page we are asking for is unmapped 3096 // it returns -1,ENOMEM 3097 mincore_return_value = mincore(nbot, page_sz, vec); 3098 3099 if (mincore_return_value == -1) { 3100 // Page is not mapped go up 3101 // to find first mapped page 3102 if (errno != EAGAIN) { 3103 assert(errno == ENOMEM, "Unexpected mincore errno"); 3104 imax = imid; 3105 } 3106 } else { 3107 // Page is mapped go down 3108 // to find first not mapped page 3109 imin = imid + 1; 3110 } 3111 } 3112 3113 nbot = nbot + page_sz; 3114 3115 // Adjust stack bottom one page up if last checked page is not mapped 3116 if (mincore_return_value == -1) { 3117 nbot = nbot + page_sz; 3118 } 3119 3120 return nbot; 3121 } 3122 3123 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) { 3124 int mincore_return_value; 3125 const size_t stripe = 1024; // query this many pages each time 3126 unsigned char vec[stripe + 1]; 3127 // set a guard 3128 vec[stripe] = 'X'; 3129 3130 const size_t page_sz = os::vm_page_size(); 3131 size_t pages = size / page_sz; 3132 3133 assert(is_aligned(start, page_sz), "Start address must be page aligned"); 3134 assert(is_aligned(size, page_sz), "Size must be page aligned"); 3135 3136 committed_start = NULL; 3137 3138 int loops = (pages + stripe - 1) / stripe; 3139 int committed_pages = 0; 3140 address loop_base = start; 3141 bool found_range = false; 3142 3143 for (int index = 0; index < loops && !found_range; index ++) { 3144 assert(pages > 0, "Nothing to do"); 3145 int pages_to_query = (pages >= stripe) ? stripe : pages; 3146 pages -= pages_to_query; 3147 3148 // Get stable read 3149 while ((mincore_return_value = mincore(loop_base, pages_to_query * page_sz, vec)) == -1 && errno == EAGAIN); 3150 3151 // During shutdown, some memory goes away without properly notifying NMT, 3152 // E.g. ConcurrentGCThread/WatcherThread can exit without deleting thread object. 3153 // Bailout and return as not committed for now. 3154 if (mincore_return_value == -1 && errno == ENOMEM) { 3155 return false; 3156 } 3157 3158 assert(vec[stripe] == 'X', "overflow guard"); 3159 assert(mincore_return_value == 0, "Range must be valid"); 3160 // Process this stripe 3161 for (int vecIdx = 0; vecIdx < pages_to_query; vecIdx ++) { 3162 if ((vec[vecIdx] & 0x01) == 0) { // not committed 3163 // End of current contiguous region 3164 if (committed_start != NULL) { 3165 found_range = true; 3166 break; 3167 } 3168 } else { // committed 3169 // Start of region 3170 if (committed_start == NULL) { 3171 committed_start = loop_base + page_sz * vecIdx; 3172 } 3173 committed_pages ++; 3174 } 3175 } 3176 3177 loop_base += pages_to_query * page_sz; 3178 } 3179 3180 if (committed_start != NULL) { 3181 assert(committed_pages > 0, "Must have committed region"); 3182 assert(committed_pages <= int(size / page_sz), "Can not commit more than it has"); 3183 assert(committed_start >= start && committed_start < start + size, "Out of range"); 3184 committed_size = page_sz * committed_pages; 3185 return true; 3186 } else { 3187 assert(committed_pages == 0, "Should not have committed region"); 3188 return false; 3189 } 3190 } 3191 3192 3193 // Linux uses a growable mapping for the stack, and if the mapping for 3194 // the stack guard pages is not removed when we detach a thread the 3195 // stack cannot grow beyond the pages where the stack guard was 3196 // mapped. If at some point later in the process the stack expands to 3197 // that point, the Linux kernel cannot expand the stack any further 3198 // because the guard pages are in the way, and a segfault occurs. 3199 // 3200 // However, it's essential not to split the stack region by unmapping 3201 // a region (leaving a hole) that's already part of the stack mapping, 3202 // so if the stack mapping has already grown beyond the guard pages at 3203 // the time we create them, we have to truncate the stack mapping. 3204 // So, we need to know the extent of the stack mapping when 3205 // create_stack_guard_pages() is called. 3206 3207 // We only need this for stacks that are growable: at the time of 3208 // writing thread stacks don't use growable mappings (i.e. those 3209 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this 3210 // only applies to the main thread. 3211 3212 // If the (growable) stack mapping already extends beyond the point 3213 // where we're going to put our guard pages, truncate the mapping at 3214 // that point by munmap()ping it. This ensures that when we later 3215 // munmap() the guard pages we don't leave a hole in the stack 3216 // mapping. This only affects the main/primordial thread 3217 3218 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 3219 if (os::is_primordial_thread()) { 3220 // As we manually grow stack up to bottom inside create_attached_thread(), 3221 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and 3222 // we don't need to do anything special. 3223 // Check it first, before calling heavy function. 3224 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom(); 3225 unsigned char vec[1]; 3226 3227 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) { 3228 // Fallback to slow path on all errors, including EAGAIN 3229 stack_extent = (uintptr_t) get_stack_commited_bottom( 3230 os::Linux::initial_thread_stack_bottom(), 3231 (size_t)addr - stack_extent); 3232 } 3233 3234 if (stack_extent < (uintptr_t)addr) { 3235 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent)); 3236 } 3237 } 3238 3239 return os::commit_memory(addr, size, !ExecMem); 3240 } 3241 3242 // If this is a growable mapping, remove the guard pages entirely by 3243 // munmap()ping them. If not, just call uncommit_memory(). This only 3244 // affects the main/primordial thread, but guard against future OS changes. 3245 // It's safe to always unmap guard pages for primordial thread because we 3246 // always place it right after end of the mapped region. 3247 3248 bool os::remove_stack_guard_pages(char* addr, size_t size) { 3249 uintptr_t stack_extent, stack_base; 3250 3251 if (os::is_primordial_thread()) { 3252 return ::munmap(addr, size) == 0; 3253 } 3254 3255 return os::uncommit_memory(addr, size); 3256 } 3257 3258 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 3259 // at 'requested_addr'. If there are existing memory mappings at the same 3260 // location, however, they will be overwritten. If 'fixed' is false, 3261 // 'requested_addr' is only treated as a hint, the return value may or 3262 // may not start from the requested address. Unlike Linux mmap(), this 3263 // function returns NULL to indicate failure. 3264 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 3265 char * addr; 3266 int flags; 3267 3268 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 3269 if (fixed) { 3270 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address"); 3271 flags |= MAP_FIXED; 3272 } 3273 3274 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 3275 // touch an uncommitted page. Otherwise, the read/write might 3276 // succeed if we have enough swap space to back the physical page. 3277 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 3278 flags, -1, 0); 3279 3280 return addr == MAP_FAILED ? NULL : addr; 3281 } 3282 3283 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address 3284 // (req_addr != NULL) or with a given alignment. 3285 // - bytes shall be a multiple of alignment. 3286 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3287 // - alignment sets the alignment at which memory shall be allocated. 3288 // It must be a multiple of allocation granularity. 3289 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3290 // req_addr or NULL. 3291 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) { 3292 3293 size_t extra_size = bytes; 3294 if (req_addr == NULL && alignment > 0) { 3295 extra_size += alignment; 3296 } 3297 3298 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE, 3299 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 3300 -1, 0); 3301 if (start == MAP_FAILED) { 3302 start = NULL; 3303 } else { 3304 if (req_addr != NULL) { 3305 if (start != req_addr) { 3306 ::munmap(start, extra_size); 3307 start = NULL; 3308 } 3309 } else { 3310 char* const start_aligned = align_up(start, alignment); 3311 char* const end_aligned = start_aligned + bytes; 3312 char* const end = start + extra_size; 3313 if (start_aligned > start) { 3314 ::munmap(start, start_aligned - start); 3315 } 3316 if (end_aligned < end) { 3317 ::munmap(end_aligned, end - end_aligned); 3318 } 3319 start = start_aligned; 3320 } 3321 } 3322 return start; 3323 } 3324 3325 static int anon_munmap(char * addr, size_t size) { 3326 return ::munmap(addr, size) == 0; 3327 } 3328 3329 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 3330 size_t alignment_hint) { 3331 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 3332 } 3333 3334 bool os::pd_release_memory(char* addr, size_t size) { 3335 return anon_munmap(addr, size); 3336 } 3337 3338 static bool linux_mprotect(char* addr, size_t size, int prot) { 3339 // Linux wants the mprotect address argument to be page aligned. 3340 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size()); 3341 3342 // According to SUSv3, mprotect() should only be used with mappings 3343 // established by mmap(), and mmap() always maps whole pages. Unaligned 3344 // 'addr' likely indicates problem in the VM (e.g. trying to change 3345 // protection of malloc'ed or statically allocated memory). Check the 3346 // caller if you hit this assert. 3347 assert(addr == bottom, "sanity check"); 3348 3349 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size()); 3350 return ::mprotect(bottom, size, prot) == 0; 3351 } 3352 3353 // Set protections specified 3354 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 3355 bool is_committed) { 3356 unsigned int p = 0; 3357 switch (prot) { 3358 case MEM_PROT_NONE: p = PROT_NONE; break; 3359 case MEM_PROT_READ: p = PROT_READ; break; 3360 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 3361 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 3362 default: 3363 ShouldNotReachHere(); 3364 } 3365 // is_committed is unused. 3366 return linux_mprotect(addr, bytes, p); 3367 } 3368 3369 bool os::guard_memory(char* addr, size_t size) { 3370 return linux_mprotect(addr, size, PROT_NONE); 3371 } 3372 3373 bool os::unguard_memory(char* addr, size_t size) { 3374 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE); 3375 } 3376 3377 bool os::Linux::transparent_huge_pages_sanity_check(bool warn, 3378 size_t page_size) { 3379 bool result = false; 3380 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE, 3381 MAP_ANONYMOUS|MAP_PRIVATE, 3382 -1, 0); 3383 if (p != MAP_FAILED) { 3384 void *aligned_p = align_up(p, page_size); 3385 3386 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0; 3387 3388 munmap(p, page_size * 2); 3389 } 3390 3391 if (warn && !result) { 3392 warning("TransparentHugePages is not supported by the operating system."); 3393 } 3394 3395 return result; 3396 } 3397 3398 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) { 3399 bool result = false; 3400 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE, 3401 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, 3402 -1, 0); 3403 3404 if (p != MAP_FAILED) { 3405 // We don't know if this really is a huge page or not. 3406 FILE *fp = fopen("/proc/self/maps", "r"); 3407 if (fp) { 3408 while (!feof(fp)) { 3409 char chars[257]; 3410 long x = 0; 3411 if (fgets(chars, sizeof(chars), fp)) { 3412 if (sscanf(chars, "%lx-%*x", &x) == 1 3413 && x == (long)p) { 3414 if (strstr (chars, "hugepage")) { 3415 result = true; 3416 break; 3417 } 3418 } 3419 } 3420 } 3421 fclose(fp); 3422 } 3423 munmap(p, page_size); 3424 } 3425 3426 if (warn && !result) { 3427 warning("HugeTLBFS is not supported by the operating system."); 3428 } 3429 3430 return result; 3431 } 3432 3433 // Set the coredump_filter bits to include largepages in core dump (bit 6) 3434 // 3435 // From the coredump_filter documentation: 3436 // 3437 // - (bit 0) anonymous private memory 3438 // - (bit 1) anonymous shared memory 3439 // - (bit 2) file-backed private memory 3440 // - (bit 3) file-backed shared memory 3441 // - (bit 4) ELF header pages in file-backed private memory areas (it is 3442 // effective only if the bit 2 is cleared) 3443 // - (bit 5) hugetlb private memory 3444 // - (bit 6) hugetlb shared memory 3445 // - (bit 7) dax private memory 3446 // - (bit 8) dax shared memory 3447 // 3448 static void set_coredump_filter(bool largepages, bool dax_shared) { 3449 FILE *f; 3450 long cdm; 3451 bool filter_changed = false; 3452 3453 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { 3454 return; 3455 } 3456 3457 if (fscanf(f, "%lx", &cdm) != 1) { 3458 fclose(f); 3459 return; 3460 } 3461 3462 rewind(f); 3463 3464 if (largepages && (cdm & LARGEPAGES_BIT) == 0) { 3465 cdm |= LARGEPAGES_BIT; 3466 filter_changed = true; 3467 } 3468 if (dax_shared && (cdm & DAX_SHARED_BIT) == 0) { 3469 cdm |= DAX_SHARED_BIT; 3470 filter_changed = true; 3471 } 3472 if (filter_changed) { 3473 fprintf(f, "%#lx", cdm); 3474 } 3475 3476 fclose(f); 3477 } 3478 3479 // Large page support 3480 3481 static size_t _large_page_size = 0; 3482 3483 size_t os::Linux::find_large_page_size() { 3484 size_t large_page_size = 0; 3485 3486 // large_page_size on Linux is used to round up heap size. x86 uses either 3487 // 2M or 4M page, depending on whether PAE (Physical Address Extensions) 3488 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use 3489 // page as large as 256M. 3490 // 3491 // Here we try to figure out page size by parsing /proc/meminfo and looking 3492 // for a line with the following format: 3493 // Hugepagesize: 2048 kB 3494 // 3495 // If we can't determine the value (e.g. /proc is not mounted, or the text 3496 // format has been changed), we'll use the largest page size supported by 3497 // the processor. 3498 3499 #ifndef ZERO 3500 large_page_size = 3501 AARCH64_ONLY(2 * M) 3502 AMD64_ONLY(2 * M) 3503 ARM32_ONLY(2 * M) 3504 IA32_ONLY(4 * M) 3505 IA64_ONLY(256 * M) 3506 PPC_ONLY(4 * M) 3507 S390_ONLY(1 * M) 3508 SPARC_ONLY(4 * M); 3509 #endif // ZERO 3510 3511 FILE *fp = fopen("/proc/meminfo", "r"); 3512 if (fp) { 3513 while (!feof(fp)) { 3514 int x = 0; 3515 char buf[16]; 3516 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { 3517 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { 3518 large_page_size = x * K; 3519 break; 3520 } 3521 } else { 3522 // skip to next line 3523 for (;;) { 3524 int ch = fgetc(fp); 3525 if (ch == EOF || ch == (int)'\n') break; 3526 } 3527 } 3528 } 3529 fclose(fp); 3530 } 3531 3532 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) { 3533 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is " 3534 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size), 3535 proper_unit_for_byte_size(large_page_size)); 3536 } 3537 3538 return large_page_size; 3539 } 3540 3541 size_t os::Linux::setup_large_page_size() { 3542 _large_page_size = Linux::find_large_page_size(); 3543 const size_t default_page_size = (size_t)Linux::page_size(); 3544 if (_large_page_size > default_page_size) { 3545 _page_sizes[0] = _large_page_size; 3546 _page_sizes[1] = default_page_size; 3547 _page_sizes[2] = 0; 3548 } 3549 3550 return _large_page_size; 3551 } 3552 3553 bool os::Linux::setup_large_page_type(size_t page_size) { 3554 if (FLAG_IS_DEFAULT(UseHugeTLBFS) && 3555 FLAG_IS_DEFAULT(UseSHM) && 3556 FLAG_IS_DEFAULT(UseTransparentHugePages)) { 3557 3558 // The type of large pages has not been specified by the user. 3559 3560 // Try UseHugeTLBFS and then UseSHM. 3561 UseHugeTLBFS = UseSHM = true; 3562 3563 // Don't try UseTransparentHugePages since there are known 3564 // performance issues with it turned on. This might change in the future. 3565 UseTransparentHugePages = false; 3566 } 3567 3568 if (UseTransparentHugePages) { 3569 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages); 3570 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) { 3571 UseHugeTLBFS = false; 3572 UseSHM = false; 3573 return true; 3574 } 3575 UseTransparentHugePages = false; 3576 } 3577 3578 if (UseHugeTLBFS) { 3579 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); 3580 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) { 3581 UseSHM = false; 3582 return true; 3583 } 3584 UseHugeTLBFS = false; 3585 } 3586 3587 return UseSHM; 3588 } 3589 3590 void os::large_page_init() { 3591 if (!UseLargePages && 3592 !UseTransparentHugePages && 3593 !UseHugeTLBFS && 3594 !UseSHM) { 3595 // Not using large pages. 3596 return; 3597 } 3598 3599 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) { 3600 // The user explicitly turned off large pages. 3601 // Ignore the rest of the large pages flags. 3602 UseTransparentHugePages = false; 3603 UseHugeTLBFS = false; 3604 UseSHM = false; 3605 return; 3606 } 3607 3608 size_t large_page_size = Linux::setup_large_page_size(); 3609 UseLargePages = Linux::setup_large_page_type(large_page_size); 3610 3611 set_coredump_filter(true /*largepages*/, false /*dax_shared*/); 3612 } 3613 3614 #ifndef SHM_HUGETLB 3615 #define SHM_HUGETLB 04000 3616 #endif 3617 3618 #define shm_warning_format(format, ...) \ 3619 do { \ 3620 if (UseLargePages && \ 3621 (!FLAG_IS_DEFAULT(UseLargePages) || \ 3622 !FLAG_IS_DEFAULT(UseSHM) || \ 3623 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \ 3624 warning(format, __VA_ARGS__); \ 3625 } \ 3626 } while (0) 3627 3628 #define shm_warning(str) shm_warning_format("%s", str) 3629 3630 #define shm_warning_with_errno(str) \ 3631 do { \ 3632 int err = errno; \ 3633 shm_warning_format(str " (error = %d)", err); \ 3634 } while (0) 3635 3636 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) { 3637 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment"); 3638 3639 if (!is_aligned(alignment, SHMLBA)) { 3640 assert(false, "Code below assumes that alignment is at least SHMLBA aligned"); 3641 return NULL; 3642 } 3643 3644 // To ensure that we get 'alignment' aligned memory from shmat, 3645 // we pre-reserve aligned virtual memory and then attach to that. 3646 3647 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL); 3648 if (pre_reserved_addr == NULL) { 3649 // Couldn't pre-reserve aligned memory. 3650 shm_warning("Failed to pre-reserve aligned memory for shmat."); 3651 return NULL; 3652 } 3653 3654 // SHM_REMAP is needed to allow shmat to map over an existing mapping. 3655 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP); 3656 3657 if ((intptr_t)addr == -1) { 3658 int err = errno; 3659 shm_warning_with_errno("Failed to attach shared memory."); 3660 3661 assert(err != EACCES, "Unexpected error"); 3662 assert(err != EIDRM, "Unexpected error"); 3663 assert(err != EINVAL, "Unexpected error"); 3664 3665 // Since we don't know if the kernel unmapped the pre-reserved memory area 3666 // we can't unmap it, since that would potentially unmap memory that was 3667 // mapped from other threads. 3668 return NULL; 3669 } 3670 3671 return addr; 3672 } 3673 3674 static char* shmat_at_address(int shmid, char* req_addr) { 3675 if (!is_aligned(req_addr, SHMLBA)) { 3676 assert(false, "Requested address needs to be SHMLBA aligned"); 3677 return NULL; 3678 } 3679 3680 char* addr = (char*)shmat(shmid, req_addr, 0); 3681 3682 if ((intptr_t)addr == -1) { 3683 shm_warning_with_errno("Failed to attach shared memory."); 3684 return NULL; 3685 } 3686 3687 return addr; 3688 } 3689 3690 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) { 3691 // If a req_addr has been provided, we assume that the caller has already aligned the address. 3692 if (req_addr != NULL) { 3693 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size"); 3694 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment"); 3695 return shmat_at_address(shmid, req_addr); 3696 } 3697 3698 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically 3699 // return large page size aligned memory addresses when req_addr == NULL. 3700 // However, if the alignment is larger than the large page size, we have 3701 // to manually ensure that the memory returned is 'alignment' aligned. 3702 if (alignment > os::large_page_size()) { 3703 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size"); 3704 return shmat_with_alignment(shmid, bytes, alignment); 3705 } else { 3706 return shmat_at_address(shmid, NULL); 3707 } 3708 } 3709 3710 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment, 3711 char* req_addr, bool exec) { 3712 // "exec" is passed in but not used. Creating the shared image for 3713 // the code cache doesn't have an SHM_X executable permission to check. 3714 assert(UseLargePages && UseSHM, "only for SHM large pages"); 3715 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3716 assert(is_aligned(req_addr, alignment), "Unaligned address"); 3717 3718 if (!is_aligned(bytes, os::large_page_size())) { 3719 return NULL; // Fallback to small pages. 3720 } 3721 3722 // Create a large shared memory region to attach to based on size. 3723 // Currently, size is the total size of the heap. 3724 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); 3725 if (shmid == -1) { 3726 // Possible reasons for shmget failure: 3727 // 1. shmmax is too small for Java heap. 3728 // > check shmmax value: cat /proc/sys/kernel/shmmax 3729 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 3730 // 2. not enough large page memory. 3731 // > check available large pages: cat /proc/meminfo 3732 // > increase amount of large pages: 3733 // echo new_value > /proc/sys/vm/nr_hugepages 3734 // Note 1: different Linux may use different name for this property, 3735 // e.g. on Redhat AS-3 it is "hugetlb_pool". 3736 // Note 2: it's possible there's enough physical memory available but 3737 // they are so fragmented after a long run that they can't 3738 // coalesce into large pages. Try to reserve large pages when 3739 // the system is still "fresh". 3740 shm_warning_with_errno("Failed to reserve shared memory."); 3741 return NULL; 3742 } 3743 3744 // Attach to the region. 3745 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr); 3746 3747 // Remove shmid. If shmat() is successful, the actual shared memory segment 3748 // will be deleted when it's detached by shmdt() or when the process 3749 // terminates. If shmat() is not successful this will remove the shared 3750 // segment immediately. 3751 shmctl(shmid, IPC_RMID, NULL); 3752 3753 return addr; 3754 } 3755 3756 static void warn_on_large_pages_failure(char* req_addr, size_t bytes, 3757 int error) { 3758 assert(error == ENOMEM, "Only expect to fail if no memory is available"); 3759 3760 bool warn_on_failure = UseLargePages && 3761 (!FLAG_IS_DEFAULT(UseLargePages) || 3762 !FLAG_IS_DEFAULT(UseHugeTLBFS) || 3763 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 3764 3765 if (warn_on_failure) { 3766 char msg[128]; 3767 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: " 3768 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error); 3769 warning("%s", msg); 3770 } 3771 } 3772 3773 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes, 3774 char* req_addr, 3775 bool exec) { 3776 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3777 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size"); 3778 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3779 3780 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3781 char* addr = (char*)::mmap(req_addr, bytes, prot, 3782 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, 3783 -1, 0); 3784 3785 if (addr == MAP_FAILED) { 3786 warn_on_large_pages_failure(req_addr, bytes, errno); 3787 return NULL; 3788 } 3789 3790 assert(is_aligned(addr, os::large_page_size()), "Must be"); 3791 3792 return addr; 3793 } 3794 3795 // Reserve memory using mmap(MAP_HUGETLB). 3796 // - bytes shall be a multiple of alignment. 3797 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3798 // - alignment sets the alignment at which memory shall be allocated. 3799 // It must be a multiple of allocation granularity. 3800 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3801 // req_addr or NULL. 3802 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes, 3803 size_t alignment, 3804 char* req_addr, 3805 bool exec) { 3806 size_t large_page_size = os::large_page_size(); 3807 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes"); 3808 3809 assert(is_aligned(req_addr, alignment), "Must be"); 3810 assert(is_aligned(bytes, alignment), "Must be"); 3811 3812 // First reserve - but not commit - the address range in small pages. 3813 char* const start = anon_mmap_aligned(bytes, alignment, req_addr); 3814 3815 if (start == NULL) { 3816 return NULL; 3817 } 3818 3819 assert(is_aligned(start, alignment), "Must be"); 3820 3821 char* end = start + bytes; 3822 3823 // Find the regions of the allocated chunk that can be promoted to large pages. 3824 char* lp_start = align_up(start, large_page_size); 3825 char* lp_end = align_down(end, large_page_size); 3826 3827 size_t lp_bytes = lp_end - lp_start; 3828 3829 assert(is_aligned(lp_bytes, large_page_size), "Must be"); 3830 3831 if (lp_bytes == 0) { 3832 // The mapped region doesn't even span the start and the end of a large page. 3833 // Fall back to allocate a non-special area. 3834 ::munmap(start, end - start); 3835 return NULL; 3836 } 3837 3838 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3839 3840 void* result; 3841 3842 // Commit small-paged leading area. 3843 if (start != lp_start) { 3844 result = ::mmap(start, lp_start - start, prot, 3845 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3846 -1, 0); 3847 if (result == MAP_FAILED) { 3848 ::munmap(lp_start, end - lp_start); 3849 return NULL; 3850 } 3851 } 3852 3853 // Commit large-paged area. 3854 result = ::mmap(lp_start, lp_bytes, prot, 3855 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB, 3856 -1, 0); 3857 if (result == MAP_FAILED) { 3858 warn_on_large_pages_failure(lp_start, lp_bytes, errno); 3859 // If the mmap above fails, the large pages region will be unmapped and we 3860 // have regions before and after with small pages. Release these regions. 3861 // 3862 // | mapped | unmapped | mapped | 3863 // ^ ^ ^ ^ 3864 // start lp_start lp_end end 3865 // 3866 ::munmap(start, lp_start - start); 3867 ::munmap(lp_end, end - lp_end); 3868 return NULL; 3869 } 3870 3871 // Commit small-paged trailing area. 3872 if (lp_end != end) { 3873 result = ::mmap(lp_end, end - lp_end, prot, 3874 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3875 -1, 0); 3876 if (result == MAP_FAILED) { 3877 ::munmap(start, lp_end - start); 3878 return NULL; 3879 } 3880 } 3881 3882 return start; 3883 } 3884 3885 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes, 3886 size_t alignment, 3887 char* req_addr, 3888 bool exec) { 3889 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3890 assert(is_aligned(req_addr, alignment), "Must be"); 3891 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be"); 3892 assert(is_power_of_2(os::large_page_size()), "Must be"); 3893 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes"); 3894 3895 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) { 3896 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec); 3897 } else { 3898 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec); 3899 } 3900 } 3901 3902 char* os::reserve_memory_special(size_t bytes, size_t alignment, 3903 char* req_addr, bool exec) { 3904 assert(UseLargePages, "only for large pages"); 3905 3906 char* addr; 3907 if (UseSHM) { 3908 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec); 3909 } else { 3910 assert(UseHugeTLBFS, "must be"); 3911 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec); 3912 } 3913 3914 if (addr != NULL) { 3915 if (UseNUMAInterleaving) { 3916 numa_make_global(addr, bytes); 3917 } 3918 3919 // The memory is committed 3920 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 3921 } 3922 3923 return addr; 3924 } 3925 3926 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) { 3927 // detaching the SHM segment will also delete it, see reserve_memory_special_shm() 3928 return shmdt(base) == 0; 3929 } 3930 3931 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) { 3932 return pd_release_memory(base, bytes); 3933 } 3934 3935 bool os::release_memory_special(char* base, size_t bytes) { 3936 bool res; 3937 if (MemTracker::tracking_level() > NMT_minimal) { 3938 Tracker tkr(Tracker::release); 3939 res = os::Linux::release_memory_special_impl(base, bytes); 3940 if (res) { 3941 tkr.record((address)base, bytes); 3942 } 3943 3944 } else { 3945 res = os::Linux::release_memory_special_impl(base, bytes); 3946 } 3947 return res; 3948 } 3949 3950 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) { 3951 assert(UseLargePages, "only for large pages"); 3952 bool res; 3953 3954 if (UseSHM) { 3955 res = os::Linux::release_memory_special_shm(base, bytes); 3956 } else { 3957 assert(UseHugeTLBFS, "must be"); 3958 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes); 3959 } 3960 return res; 3961 } 3962 3963 size_t os::large_page_size() { 3964 return _large_page_size; 3965 } 3966 3967 // With SysV SHM the entire memory region must be allocated as shared 3968 // memory. 3969 // HugeTLBFS allows application to commit large page memory on demand. 3970 // However, when committing memory with HugeTLBFS fails, the region 3971 // that was supposed to be committed will lose the old reservation 3972 // and allow other threads to steal that memory region. Because of this 3973 // behavior we can't commit HugeTLBFS memory. 3974 bool os::can_commit_large_page_memory() { 3975 return UseTransparentHugePages; 3976 } 3977 3978 bool os::can_execute_large_page_memory() { 3979 return UseTransparentHugePages || UseHugeTLBFS; 3980 } 3981 3982 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) { 3983 assert(file_desc >= 0, "file_desc is not valid"); 3984 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr); 3985 if (result != NULL) { 3986 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) { 3987 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory")); 3988 } 3989 } 3990 return result; 3991 } 3992 3993 // Reserve memory at an arbitrary address, only if that area is 3994 // available (and not reserved for something else). 3995 3996 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 3997 const int max_tries = 10; 3998 char* base[max_tries]; 3999 size_t size[max_tries]; 4000 const size_t gap = 0x000000; 4001 4002 // Assert only that the size is a multiple of the page size, since 4003 // that's all that mmap requires, and since that's all we really know 4004 // about at this low abstraction level. If we need higher alignment, 4005 // we can either pass an alignment to this method or verify alignment 4006 // in one of the methods further up the call chain. See bug 5044738. 4007 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 4008 4009 // Repeatedly allocate blocks until the block is allocated at the 4010 // right spot. 4011 4012 // Linux mmap allows caller to pass an address as hint; give it a try first, 4013 // if kernel honors the hint then we can return immediately. 4014 char * addr = anon_mmap(requested_addr, bytes, false); 4015 if (addr == requested_addr) { 4016 return requested_addr; 4017 } 4018 4019 if (addr != NULL) { 4020 // mmap() is successful but it fails to reserve at the requested address 4021 anon_munmap(addr, bytes); 4022 } 4023 4024 int i; 4025 for (i = 0; i < max_tries; ++i) { 4026 base[i] = reserve_memory(bytes); 4027 4028 if (base[i] != NULL) { 4029 // Is this the block we wanted? 4030 if (base[i] == requested_addr) { 4031 size[i] = bytes; 4032 break; 4033 } 4034 4035 // Does this overlap the block we wanted? Give back the overlapped 4036 // parts and try again. 4037 4038 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i]; 4039 if (top_overlap >= 0 && (size_t)top_overlap < bytes) { 4040 unmap_memory(base[i], top_overlap); 4041 base[i] += top_overlap; 4042 size[i] = bytes - top_overlap; 4043 } else { 4044 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr; 4045 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) { 4046 unmap_memory(requested_addr, bottom_overlap); 4047 size[i] = bytes - bottom_overlap; 4048 } else { 4049 size[i] = bytes; 4050 } 4051 } 4052 } 4053 } 4054 4055 // Give back the unused reserved pieces. 4056 4057 for (int j = 0; j < i; ++j) { 4058 if (base[j] != NULL) { 4059 unmap_memory(base[j], size[j]); 4060 } 4061 } 4062 4063 if (i < max_tries) { 4064 return requested_addr; 4065 } else { 4066 return NULL; 4067 } 4068 } 4069 4070 size_t os::read(int fd, void *buf, unsigned int nBytes) { 4071 return ::read(fd, buf, nBytes); 4072 } 4073 4074 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 4075 return ::pread(fd, buf, nBytes, offset); 4076 } 4077 4078 // Short sleep, direct OS call. 4079 // 4080 // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee 4081 // sched_yield(2) will actually give up the CPU: 4082 // 4083 // * Alone on this pariticular CPU, keeps running. 4084 // * Before the introduction of "skip_buddy" with "compat_yield" disabled 4085 // (pre 2.6.39). 4086 // 4087 // So calling this with 0 is an alternative. 4088 // 4089 void os::naked_short_sleep(jlong ms) { 4090 struct timespec req; 4091 4092 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 4093 req.tv_sec = 0; 4094 if (ms > 0) { 4095 req.tv_nsec = (ms % 1000) * 1000000; 4096 } else { 4097 req.tv_nsec = 1; 4098 } 4099 4100 nanosleep(&req, NULL); 4101 4102 return; 4103 } 4104 4105 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 4106 void os::infinite_sleep() { 4107 while (true) { // sleep forever ... 4108 ::sleep(100); // ... 100 seconds at a time 4109 } 4110 } 4111 4112 // Used to convert frequent JVM_Yield() to nops 4113 bool os::dont_yield() { 4114 return DontYieldALot; 4115 } 4116 4117 void os::naked_yield() { 4118 sched_yield(); 4119 } 4120 4121 //////////////////////////////////////////////////////////////////////////////// 4122 // thread priority support 4123 4124 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER 4125 // only supports dynamic priority, static priority must be zero. For real-time 4126 // applications, Linux supports SCHED_RR which allows static priority (1-99). 4127 // However, for large multi-threaded applications, SCHED_RR is not only slower 4128 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 4129 // of 5 runs - Sep 2005). 4130 // 4131 // The following code actually changes the niceness of kernel-thread/LWP. It 4132 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 4133 // not the entire user process, and user level threads are 1:1 mapped to kernel 4134 // threads. It has always been the case, but could change in the future. For 4135 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 4136 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 4137 4138 int os::java_to_os_priority[CriticalPriority + 1] = { 4139 19, // 0 Entry should never be used 4140 4141 4, // 1 MinPriority 4142 3, // 2 4143 2, // 3 4144 4145 1, // 4 4146 0, // 5 NormPriority 4147 -1, // 6 4148 4149 -2, // 7 4150 -3, // 8 4151 -4, // 9 NearMaxPriority 4152 4153 -5, // 10 MaxPriority 4154 4155 -5 // 11 CriticalPriority 4156 }; 4157 4158 static int prio_init() { 4159 if (ThreadPriorityPolicy == 1) { 4160 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 4161 // if effective uid is not root. Perhaps, a more elegant way of doing 4162 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 4163 if (geteuid() != 0) { 4164 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 4165 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux"); 4166 } 4167 ThreadPriorityPolicy = 0; 4168 } 4169 } 4170 if (UseCriticalJavaThreadPriority) { 4171 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 4172 } 4173 return 0; 4174 } 4175 4176 OSReturn os::set_native_priority(Thread* thread, int newpri) { 4177 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 4178 4179 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 4180 return (ret == 0) ? OS_OK : OS_ERR; 4181 } 4182 4183 OSReturn os::get_native_priority(const Thread* const thread, 4184 int *priority_ptr) { 4185 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 4186 *priority_ptr = java_to_os_priority[NormPriority]; 4187 return OS_OK; 4188 } 4189 4190 errno = 0; 4191 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 4192 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 4193 } 4194 4195 //////////////////////////////////////////////////////////////////////////////// 4196 // suspend/resume support 4197 4198 // The low-level signal-based suspend/resume support is a remnant from the 4199 // old VM-suspension that used to be for java-suspension, safepoints etc, 4200 // within hotspot. Currently used by JFR's OSThreadSampler 4201 // 4202 // The remaining code is greatly simplified from the more general suspension 4203 // code that used to be used. 4204 // 4205 // The protocol is quite simple: 4206 // - suspend: 4207 // - sends a signal to the target thread 4208 // - polls the suspend state of the osthread using a yield loop 4209 // - target thread signal handler (SR_handler) sets suspend state 4210 // and blocks in sigsuspend until continued 4211 // - resume: 4212 // - sets target osthread state to continue 4213 // - sends signal to end the sigsuspend loop in the SR_handler 4214 // 4215 // Note that the SR_lock plays no role in this suspend/resume protocol, 4216 // but is checked for NULL in SR_handler as a thread termination indicator. 4217 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs. 4218 // 4219 // Note that resume_clear_context() and suspend_save_context() are needed 4220 // by SR_handler(), so that fetch_frame_from_ucontext() works, 4221 // which in part is used by: 4222 // - Forte Analyzer: AsyncGetCallTrace() 4223 // - StackBanging: get_frame_at_stack_banging_point() 4224 4225 static void resume_clear_context(OSThread *osthread) { 4226 osthread->set_ucontext(NULL); 4227 osthread->set_siginfo(NULL); 4228 } 4229 4230 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, 4231 ucontext_t* context) { 4232 osthread->set_ucontext(context); 4233 osthread->set_siginfo(siginfo); 4234 } 4235 4236 // Handler function invoked when a thread's execution is suspended or 4237 // resumed. We have to be careful that only async-safe functions are 4238 // called here (Note: most pthread functions are not async safe and 4239 // should be avoided.) 4240 // 4241 // Note: sigwait() is a more natural fit than sigsuspend() from an 4242 // interface point of view, but sigwait() prevents the signal hander 4243 // from being run. libpthread would get very confused by not having 4244 // its signal handlers run and prevents sigwait()'s use with the 4245 // mutex granting granting signal. 4246 // 4247 // Currently only ever called on the VMThread and JavaThreads (PC sampling) 4248 // 4249 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 4250 // Save and restore errno to avoid confusing native code with EINTR 4251 // after sigsuspend. 4252 int old_errno = errno; 4253 4254 Thread* thread = Thread::current_or_null_safe(); 4255 assert(thread != NULL, "Missing current thread in SR_handler"); 4256 4257 // On some systems we have seen signal delivery get "stuck" until the signal 4258 // mask is changed as part of thread termination. Check that the current thread 4259 // has not already terminated (via SR_lock()) - else the following assertion 4260 // will fail because the thread is no longer a JavaThread as the ~JavaThread 4261 // destructor has completed. 4262 4263 if (thread->SR_lock() == NULL) { 4264 return; 4265 } 4266 4267 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 4268 4269 OSThread* osthread = thread->osthread(); 4270 4271 os::SuspendResume::State current = osthread->sr.state(); 4272 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 4273 suspend_save_context(osthread, siginfo, context); 4274 4275 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 4276 os::SuspendResume::State state = osthread->sr.suspended(); 4277 if (state == os::SuspendResume::SR_SUSPENDED) { 4278 sigset_t suspend_set; // signals for sigsuspend() 4279 sigemptyset(&suspend_set); 4280 // get current set of blocked signals and unblock resume signal 4281 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 4282 sigdelset(&suspend_set, SR_signum); 4283 4284 sr_semaphore.signal(); 4285 // wait here until we are resumed 4286 while (1) { 4287 sigsuspend(&suspend_set); 4288 4289 os::SuspendResume::State result = osthread->sr.running(); 4290 if (result == os::SuspendResume::SR_RUNNING) { 4291 sr_semaphore.signal(); 4292 break; 4293 } 4294 } 4295 4296 } else if (state == os::SuspendResume::SR_RUNNING) { 4297 // request was cancelled, continue 4298 } else { 4299 ShouldNotReachHere(); 4300 } 4301 4302 resume_clear_context(osthread); 4303 } else if (current == os::SuspendResume::SR_RUNNING) { 4304 // request was cancelled, continue 4305 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 4306 // ignore 4307 } else { 4308 // ignore 4309 } 4310 4311 errno = old_errno; 4312 } 4313 4314 static int SR_initialize() { 4315 struct sigaction act; 4316 char *s; 4317 4318 // Get signal number to use for suspend/resume 4319 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 4320 int sig = ::strtol(s, 0, 10); 4321 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769. 4322 sig < NSIG) { // Must be legal signal and fit into sigflags[]. 4323 SR_signum = sig; 4324 } else { 4325 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.", 4326 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum); 4327 } 4328 } 4329 4330 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 4331 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 4332 4333 sigemptyset(&SR_sigset); 4334 sigaddset(&SR_sigset, SR_signum); 4335 4336 // Set up signal handler for suspend/resume 4337 act.sa_flags = SA_RESTART|SA_SIGINFO; 4338 act.sa_handler = (void (*)(int)) SR_handler; 4339 4340 // SR_signum is blocked by default. 4341 // 4528190 - We also need to block pthread restart signal (32 on all 4342 // supported Linux platforms). Note that LinuxThreads need to block 4343 // this signal for all threads to work properly. So we don't have 4344 // to use hard-coded signal number when setting up the mask. 4345 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 4346 4347 if (sigaction(SR_signum, &act, 0) == -1) { 4348 return -1; 4349 } 4350 4351 // Save signal flag 4352 os::Linux::set_our_sigflags(SR_signum, act.sa_flags); 4353 return 0; 4354 } 4355 4356 static int sr_notify(OSThread* osthread) { 4357 int status = pthread_kill(osthread->pthread_id(), SR_signum); 4358 assert_status(status == 0, status, "pthread_kill"); 4359 return status; 4360 } 4361 4362 // "Randomly" selected value for how long we want to spin 4363 // before bailing out on suspending a thread, also how often 4364 // we send a signal to a thread we want to resume 4365 static const int RANDOMLY_LARGE_INTEGER = 1000000; 4366 static const int RANDOMLY_LARGE_INTEGER2 = 100; 4367 4368 // returns true on success and false on error - really an error is fatal 4369 // but this seems the normal response to library errors 4370 static bool do_suspend(OSThread* osthread) { 4371 assert(osthread->sr.is_running(), "thread should be running"); 4372 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 4373 4374 // mark as suspended and send signal 4375 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 4376 // failed to switch, state wasn't running? 4377 ShouldNotReachHere(); 4378 return false; 4379 } 4380 4381 if (sr_notify(osthread) != 0) { 4382 ShouldNotReachHere(); 4383 } 4384 4385 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 4386 while (true) { 4387 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { 4388 break; 4389 } else { 4390 // timeout 4391 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 4392 if (cancelled == os::SuspendResume::SR_RUNNING) { 4393 return false; 4394 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 4395 // make sure that we consume the signal on the semaphore as well 4396 sr_semaphore.wait(); 4397 break; 4398 } else { 4399 ShouldNotReachHere(); 4400 return false; 4401 } 4402 } 4403 } 4404 4405 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 4406 return true; 4407 } 4408 4409 static void do_resume(OSThread* osthread) { 4410 assert(osthread->sr.is_suspended(), "thread should be suspended"); 4411 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 4412 4413 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 4414 // failed to switch to WAKEUP_REQUEST 4415 ShouldNotReachHere(); 4416 return; 4417 } 4418 4419 while (true) { 4420 if (sr_notify(osthread) == 0) { 4421 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { 4422 if (osthread->sr.is_running()) { 4423 return; 4424 } 4425 } 4426 } else { 4427 ShouldNotReachHere(); 4428 } 4429 } 4430 4431 guarantee(osthread->sr.is_running(), "Must be running!"); 4432 } 4433 4434 /////////////////////////////////////////////////////////////////////////////////// 4435 // signal handling (except suspend/resume) 4436 4437 // This routine may be used by user applications as a "hook" to catch signals. 4438 // The user-defined signal handler must pass unrecognized signals to this 4439 // routine, and if it returns true (non-zero), then the signal handler must 4440 // return immediately. If the flag "abort_if_unrecognized" is true, then this 4441 // routine will never retun false (zero), but instead will execute a VM panic 4442 // routine kill the process. 4443 // 4444 // If this routine returns false, it is OK to call it again. This allows 4445 // the user-defined signal handler to perform checks either before or after 4446 // the VM performs its own checks. Naturally, the user code would be making 4447 // a serious error if it tried to handle an exception (such as a null check 4448 // or breakpoint) that the VM was generating for its own correct operation. 4449 // 4450 // This routine may recognize any of the following kinds of signals: 4451 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 4452 // It should be consulted by handlers for any of those signals. 4453 // 4454 // The caller of this routine must pass in the three arguments supplied 4455 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 4456 // field of the structure passed to sigaction(). This routine assumes that 4457 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 4458 // 4459 // Note that the VM will print warnings if it detects conflicting signal 4460 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 4461 // 4462 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo, 4463 siginfo_t* siginfo, 4464 void* ucontext, 4465 int abort_if_unrecognized); 4466 4467 static void signalHandler(int sig, siginfo_t* info, void* uc) { 4468 assert(info != NULL && uc != NULL, "it must be old kernel"); 4469 int orig_errno = errno; // Preserve errno value over signal handler. 4470 JVM_handle_linux_signal(sig, info, uc, true); 4471 errno = orig_errno; 4472 } 4473 4474 4475 // This boolean allows users to forward their own non-matching signals 4476 // to JVM_handle_linux_signal, harmlessly. 4477 bool os::Linux::signal_handlers_are_installed = false; 4478 4479 // For signal-chaining 4480 struct sigaction sigact[NSIG]; 4481 uint64_t sigs = 0; 4482 #if (64 < NSIG-1) 4483 #error "Not all signals can be encoded in sigs. Adapt its type!" 4484 #endif 4485 bool os::Linux::libjsig_is_loaded = false; 4486 typedef struct sigaction *(*get_signal_t)(int); 4487 get_signal_t os::Linux::get_signal_action = NULL; 4488 4489 struct sigaction* os::Linux::get_chained_signal_action(int sig) { 4490 struct sigaction *actp = NULL; 4491 4492 if (libjsig_is_loaded) { 4493 // Retrieve the old signal handler from libjsig 4494 actp = (*get_signal_action)(sig); 4495 } 4496 if (actp == NULL) { 4497 // Retrieve the preinstalled signal handler from jvm 4498 actp = get_preinstalled_handler(sig); 4499 } 4500 4501 return actp; 4502 } 4503 4504 static bool call_chained_handler(struct sigaction *actp, int sig, 4505 siginfo_t *siginfo, void *context) { 4506 // Call the old signal handler 4507 if (actp->sa_handler == SIG_DFL) { 4508 // It's more reasonable to let jvm treat it as an unexpected exception 4509 // instead of taking the default action. 4510 return false; 4511 } else if (actp->sa_handler != SIG_IGN) { 4512 if ((actp->sa_flags & SA_NODEFER) == 0) { 4513 // automaticlly block the signal 4514 sigaddset(&(actp->sa_mask), sig); 4515 } 4516 4517 sa_handler_t hand = NULL; 4518 sa_sigaction_t sa = NULL; 4519 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 4520 // retrieve the chained handler 4521 if (siginfo_flag_set) { 4522 sa = actp->sa_sigaction; 4523 } else { 4524 hand = actp->sa_handler; 4525 } 4526 4527 if ((actp->sa_flags & SA_RESETHAND) != 0) { 4528 actp->sa_handler = SIG_DFL; 4529 } 4530 4531 // try to honor the signal mask 4532 sigset_t oset; 4533 sigemptyset(&oset); 4534 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 4535 4536 // call into the chained handler 4537 if (siginfo_flag_set) { 4538 (*sa)(sig, siginfo, context); 4539 } else { 4540 (*hand)(sig); 4541 } 4542 4543 // restore the signal mask 4544 pthread_sigmask(SIG_SETMASK, &oset, NULL); 4545 } 4546 // Tell jvm's signal handler the signal is taken care of. 4547 return true; 4548 } 4549 4550 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) { 4551 bool chained = false; 4552 // signal-chaining 4553 if (UseSignalChaining) { 4554 struct sigaction *actp = get_chained_signal_action(sig); 4555 if (actp != NULL) { 4556 chained = call_chained_handler(actp, sig, siginfo, context); 4557 } 4558 } 4559 return chained; 4560 } 4561 4562 struct sigaction* os::Linux::get_preinstalled_handler(int sig) { 4563 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) { 4564 return &sigact[sig]; 4565 } 4566 return NULL; 4567 } 4568 4569 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 4570 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4571 sigact[sig] = oldAct; 4572 sigs |= (uint64_t)1 << (sig-1); 4573 } 4574 4575 // for diagnostic 4576 int sigflags[NSIG]; 4577 4578 int os::Linux::get_our_sigflags(int sig) { 4579 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4580 return sigflags[sig]; 4581 } 4582 4583 void os::Linux::set_our_sigflags(int sig, int flags) { 4584 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4585 if (sig > 0 && sig < NSIG) { 4586 sigflags[sig] = flags; 4587 } 4588 } 4589 4590 void os::Linux::set_signal_handler(int sig, bool set_installed) { 4591 // Check for overwrite. 4592 struct sigaction oldAct; 4593 sigaction(sig, (struct sigaction*)NULL, &oldAct); 4594 4595 void* oldhand = oldAct.sa_sigaction 4596 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4597 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4598 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 4599 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 4600 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 4601 if (AllowUserSignalHandlers || !set_installed) { 4602 // Do not overwrite; user takes responsibility to forward to us. 4603 return; 4604 } else if (UseSignalChaining) { 4605 // save the old handler in jvm 4606 save_preinstalled_handler(sig, oldAct); 4607 // libjsig also interposes the sigaction() call below and saves the 4608 // old sigaction on it own. 4609 } else { 4610 fatal("Encountered unexpected pre-existing sigaction handler " 4611 "%#lx for signal %d.", (long)oldhand, sig); 4612 } 4613 } 4614 4615 struct sigaction sigAct; 4616 sigfillset(&(sigAct.sa_mask)); 4617 sigAct.sa_handler = SIG_DFL; 4618 if (!set_installed) { 4619 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4620 } else { 4621 sigAct.sa_sigaction = signalHandler; 4622 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4623 } 4624 // Save flags, which are set by ours 4625 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4626 sigflags[sig] = sigAct.sa_flags; 4627 4628 int ret = sigaction(sig, &sigAct, &oldAct); 4629 assert(ret == 0, "check"); 4630 4631 void* oldhand2 = oldAct.sa_sigaction 4632 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4633 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4634 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 4635 } 4636 4637 // install signal handlers for signals that HotSpot needs to 4638 // handle in order to support Java-level exception handling. 4639 4640 void os::Linux::install_signal_handlers() { 4641 if (!signal_handlers_are_installed) { 4642 signal_handlers_are_installed = true; 4643 4644 // signal-chaining 4645 typedef void (*signal_setting_t)(); 4646 signal_setting_t begin_signal_setting = NULL; 4647 signal_setting_t end_signal_setting = NULL; 4648 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4649 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 4650 if (begin_signal_setting != NULL) { 4651 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4652 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 4653 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 4654 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 4655 libjsig_is_loaded = true; 4656 assert(UseSignalChaining, "should enable signal-chaining"); 4657 } 4658 if (libjsig_is_loaded) { 4659 // Tell libjsig jvm is setting signal handlers 4660 (*begin_signal_setting)(); 4661 } 4662 4663 set_signal_handler(SIGSEGV, true); 4664 set_signal_handler(SIGPIPE, true); 4665 set_signal_handler(SIGBUS, true); 4666 set_signal_handler(SIGILL, true); 4667 set_signal_handler(SIGFPE, true); 4668 #if defined(PPC64) 4669 set_signal_handler(SIGTRAP, true); 4670 #endif 4671 set_signal_handler(SIGXFSZ, true); 4672 4673 if (libjsig_is_loaded) { 4674 // Tell libjsig jvm finishes setting signal handlers 4675 (*end_signal_setting)(); 4676 } 4677 4678 // We don't activate signal checker if libjsig is in place, we trust ourselves 4679 // and if UserSignalHandler is installed all bets are off. 4680 // Log that signal checking is off only if -verbose:jni is specified. 4681 if (CheckJNICalls) { 4682 if (libjsig_is_loaded) { 4683 if (PrintJNIResolving) { 4684 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 4685 } 4686 check_signals = false; 4687 } 4688 if (AllowUserSignalHandlers) { 4689 if (PrintJNIResolving) { 4690 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 4691 } 4692 check_signals = false; 4693 } 4694 } 4695 } 4696 } 4697 4698 // This is the fastest way to get thread cpu time on Linux. 4699 // Returns cpu time (user+sys) for any thread, not only for current. 4700 // POSIX compliant clocks are implemented in the kernels 2.6.16+. 4701 // It might work on 2.6.10+ with a special kernel/glibc patch. 4702 // For reference, please, see IEEE Std 1003.1-2004: 4703 // http://www.unix.org/single_unix_specification 4704 4705 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) { 4706 struct timespec tp; 4707 int rc = os::Linux::clock_gettime(clockid, &tp); 4708 assert(rc == 0, "clock_gettime is expected to return 0 code"); 4709 4710 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec; 4711 } 4712 4713 void os::Linux::initialize_os_info() { 4714 assert(_os_version == 0, "OS info already initialized"); 4715 4716 struct utsname _uname; 4717 4718 uint32_t major; 4719 uint32_t minor; 4720 uint32_t fix; 4721 4722 int rc; 4723 4724 // Kernel version is unknown if 4725 // verification below fails. 4726 _os_version = 0x01000000; 4727 4728 rc = uname(&_uname); 4729 if (rc != -1) { 4730 4731 rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix); 4732 if (rc == 3) { 4733 4734 if (major < 256 && minor < 256 && fix < 256) { 4735 // Kernel version format is as expected, 4736 // set it overriding unknown state. 4737 _os_version = (major << 16) | 4738 (minor << 8 ) | 4739 (fix << 0 ) ; 4740 } 4741 } 4742 } 4743 } 4744 4745 uint32_t os::Linux::os_version() { 4746 assert(_os_version != 0, "not initialized"); 4747 return _os_version & 0x00FFFFFF; 4748 } 4749 4750 bool os::Linux::os_version_is_known() { 4751 assert(_os_version != 0, "not initialized"); 4752 return _os_version & 0x01000000 ? false : true; 4753 } 4754 4755 ///// 4756 // glibc on Linux platform uses non-documented flag 4757 // to indicate, that some special sort of signal 4758 // trampoline is used. 4759 // We will never set this flag, and we should 4760 // ignore this flag in our diagnostic 4761 #ifdef SIGNIFICANT_SIGNAL_MASK 4762 #undef SIGNIFICANT_SIGNAL_MASK 4763 #endif 4764 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 4765 4766 static const char* get_signal_handler_name(address handler, 4767 char* buf, int buflen) { 4768 int offset = 0; 4769 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 4770 if (found) { 4771 // skip directory names 4772 const char *p1, *p2; 4773 p1 = buf; 4774 size_t len = strlen(os::file_separator()); 4775 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 4776 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 4777 } else { 4778 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 4779 } 4780 return buf; 4781 } 4782 4783 static void print_signal_handler(outputStream* st, int sig, 4784 char* buf, size_t buflen) { 4785 struct sigaction sa; 4786 4787 sigaction(sig, NULL, &sa); 4788 4789 // See comment for SIGNIFICANT_SIGNAL_MASK define 4790 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4791 4792 st->print("%s: ", os::exception_name(sig, buf, buflen)); 4793 4794 address handler = (sa.sa_flags & SA_SIGINFO) 4795 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 4796 : CAST_FROM_FN_PTR(address, sa.sa_handler); 4797 4798 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 4799 st->print("SIG_DFL"); 4800 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 4801 st->print("SIG_IGN"); 4802 } else { 4803 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 4804 } 4805 4806 st->print(", sa_mask[0]="); 4807 os::Posix::print_signal_set_short(st, &sa.sa_mask); 4808 4809 address rh = VMError::get_resetted_sighandler(sig); 4810 // May be, handler was resetted by VMError? 4811 if (rh != NULL) { 4812 handler = rh; 4813 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 4814 } 4815 4816 st->print(", sa_flags="); 4817 os::Posix::print_sa_flags(st, sa.sa_flags); 4818 4819 // Check: is it our handler? 4820 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 4821 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 4822 // It is our signal handler 4823 // check for flags, reset system-used one! 4824 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) { 4825 st->print( 4826 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 4827 os::Linux::get_our_sigflags(sig)); 4828 } 4829 } 4830 st->cr(); 4831 } 4832 4833 4834 #define DO_SIGNAL_CHECK(sig) \ 4835 do { \ 4836 if (!sigismember(&check_signal_done, sig)) { \ 4837 os::Linux::check_signal_handler(sig); \ 4838 } \ 4839 } while (0) 4840 4841 // This method is a periodic task to check for misbehaving JNI applications 4842 // under CheckJNI, we can add any periodic checks here 4843 4844 void os::run_periodic_checks() { 4845 if (check_signals == false) return; 4846 4847 // SEGV and BUS if overridden could potentially prevent 4848 // generation of hs*.log in the event of a crash, debugging 4849 // such a case can be very challenging, so we absolutely 4850 // check the following for a good measure: 4851 DO_SIGNAL_CHECK(SIGSEGV); 4852 DO_SIGNAL_CHECK(SIGILL); 4853 DO_SIGNAL_CHECK(SIGFPE); 4854 DO_SIGNAL_CHECK(SIGBUS); 4855 DO_SIGNAL_CHECK(SIGPIPE); 4856 DO_SIGNAL_CHECK(SIGXFSZ); 4857 #if defined(PPC64) 4858 DO_SIGNAL_CHECK(SIGTRAP); 4859 #endif 4860 4861 // ReduceSignalUsage allows the user to override these handlers 4862 // see comments at the very top and jvm_md.h 4863 if (!ReduceSignalUsage) { 4864 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 4865 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 4866 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 4867 DO_SIGNAL_CHECK(BREAK_SIGNAL); 4868 } 4869 4870 DO_SIGNAL_CHECK(SR_signum); 4871 } 4872 4873 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 4874 4875 static os_sigaction_t os_sigaction = NULL; 4876 4877 void os::Linux::check_signal_handler(int sig) { 4878 char buf[O_BUFLEN]; 4879 address jvmHandler = NULL; 4880 4881 4882 struct sigaction act; 4883 if (os_sigaction == NULL) { 4884 // only trust the default sigaction, in case it has been interposed 4885 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 4886 if (os_sigaction == NULL) return; 4887 } 4888 4889 os_sigaction(sig, (struct sigaction*)NULL, &act); 4890 4891 4892 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4893 4894 address thisHandler = (act.sa_flags & SA_SIGINFO) 4895 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 4896 : CAST_FROM_FN_PTR(address, act.sa_handler); 4897 4898 4899 switch (sig) { 4900 case SIGSEGV: 4901 case SIGBUS: 4902 case SIGFPE: 4903 case SIGPIPE: 4904 case SIGILL: 4905 case SIGXFSZ: 4906 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 4907 break; 4908 4909 case SHUTDOWN1_SIGNAL: 4910 case SHUTDOWN2_SIGNAL: 4911 case SHUTDOWN3_SIGNAL: 4912 case BREAK_SIGNAL: 4913 jvmHandler = (address)user_handler(); 4914 break; 4915 4916 default: 4917 if (sig == SR_signum) { 4918 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 4919 } else { 4920 return; 4921 } 4922 break; 4923 } 4924 4925 if (thisHandler != jvmHandler) { 4926 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 4927 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 4928 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 4929 // No need to check this sig any longer 4930 sigaddset(&check_signal_done, sig); 4931 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 4932 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 4933 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 4934 exception_name(sig, buf, O_BUFLEN)); 4935 } 4936 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) { 4937 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 4938 tty->print("expected:"); 4939 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig)); 4940 tty->cr(); 4941 tty->print(" found:"); 4942 os::Posix::print_sa_flags(tty, act.sa_flags); 4943 tty->cr(); 4944 // No need to check this sig any longer 4945 sigaddset(&check_signal_done, sig); 4946 } 4947 4948 // Dump all the signal 4949 if (sigismember(&check_signal_done, sig)) { 4950 print_signal_handlers(tty, buf, O_BUFLEN); 4951 } 4952 } 4953 4954 extern void report_error(char* file_name, int line_no, char* title, 4955 char* format, ...); 4956 4957 // this is called _before_ most of the global arguments have been parsed 4958 void os::init(void) { 4959 char dummy; // used to get a guess on initial stack address 4960 4961 clock_tics_per_sec = sysconf(_SC_CLK_TCK); 4962 4963 init_random(1234567); 4964 4965 Linux::set_page_size(sysconf(_SC_PAGESIZE)); 4966 if (Linux::page_size() == -1) { 4967 fatal("os_linux.cpp: os::init: sysconf failed (%s)", 4968 os::strerror(errno)); 4969 } 4970 init_page_sizes((size_t) Linux::page_size()); 4971 4972 Linux::initialize_system_info(); 4973 4974 Linux::initialize_os_info(); 4975 4976 // _main_thread points to the thread that created/loaded the JVM. 4977 Linux::_main_thread = pthread_self(); 4978 4979 Linux::clock_init(); 4980 initial_time_count = javaTimeNanos(); 4981 4982 // retrieve entry point for pthread_setname_np 4983 Linux::_pthread_setname_np = 4984 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np"); 4985 4986 os::Posix::init(); 4987 } 4988 4989 // To install functions for atexit system call 4990 extern "C" { 4991 static void perfMemory_exit_helper() { 4992 perfMemory_exit(); 4993 } 4994 } 4995 4996 void os::pd_init_container_support() { 4997 OSContainer::init(); 4998 } 4999 5000 // this is called _after_ the global arguments have been parsed 5001 jint os::init_2(void) { 5002 5003 os::Posix::init_2(); 5004 5005 Linux::fast_thread_clock_init(); 5006 5007 // initialize suspend/resume support - must do this before signal_sets_init() 5008 if (SR_initialize() != 0) { 5009 perror("SR_initialize failed"); 5010 return JNI_ERR; 5011 } 5012 5013 Linux::signal_sets_init(); 5014 Linux::install_signal_handlers(); 5015 // Initialize data for jdk.internal.misc.Signal 5016 if (!ReduceSignalUsage) { 5017 jdk_misc_signal_init(); 5018 } 5019 5020 // Check and sets minimum stack sizes against command line options 5021 if (Posix::set_minimum_stack_sizes() == JNI_ERR) { 5022 return JNI_ERR; 5023 } 5024 5025 suppress_primordial_thread_resolution = Arguments::created_by_java_launcher(); 5026 if (!suppress_primordial_thread_resolution) { 5027 Linux::capture_initial_stack(JavaThread::stack_size_at_create()); 5028 } 5029 5030 #if defined(IA32) 5031 workaround_expand_exec_shield_cs_limit(); 5032 #endif 5033 5034 Linux::libpthread_init(); 5035 Linux::sched_getcpu_init(); 5036 log_info(os)("HotSpot is running with %s, %s", 5037 Linux::glibc_version(), Linux::libpthread_version()); 5038 5039 if (UseNUMA) { 5040 if (!Linux::libnuma_init()) { 5041 UseNUMA = false; 5042 } else { 5043 if ((Linux::numa_max_node() < 1) || Linux::isbound_to_single_node()) { 5044 // If there's only one node (they start from 0) or if the process 5045 // is bound explicitly to a single node using membind, disable NUMA. 5046 UseNUMA = false; 5047 } 5048 } 5049 5050 if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) { 5051 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way 5052 // we can make the adaptive lgrp chunk resizing work. If the user specified both 5053 // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn 5054 // and disable adaptive resizing. 5055 if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) { 5056 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, " 5057 "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)"); 5058 UseAdaptiveSizePolicy = false; 5059 UseAdaptiveNUMAChunkSizing = false; 5060 } 5061 } 5062 5063 if (!UseNUMA && ForceNUMA) { 5064 UseNUMA = true; 5065 } 5066 } 5067 5068 if (MaxFDLimit) { 5069 // set the number of file descriptors to max. print out error 5070 // if getrlimit/setrlimit fails but continue regardless. 5071 struct rlimit nbr_files; 5072 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 5073 if (status != 0) { 5074 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno)); 5075 } else { 5076 nbr_files.rlim_cur = nbr_files.rlim_max; 5077 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 5078 if (status != 0) { 5079 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno)); 5080 } 5081 } 5082 } 5083 5084 // Initialize lock used to serialize thread creation (see os::create_thread) 5085 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); 5086 5087 // at-exit methods are called in the reverse order of their registration. 5088 // atexit functions are called on return from main or as a result of a 5089 // call to exit(3C). There can be only 32 of these functions registered 5090 // and atexit() does not set errno. 5091 5092 if (PerfAllowAtExitRegistration) { 5093 // only register atexit functions if PerfAllowAtExitRegistration is set. 5094 // atexit functions can be delayed until process exit time, which 5095 // can be problematic for embedded VM situations. Embedded VMs should 5096 // call DestroyJavaVM() to assure that VM resources are released. 5097 5098 // note: perfMemory_exit_helper atexit function may be removed in 5099 // the future if the appropriate cleanup code can be added to the 5100 // VM_Exit VMOperation's doit method. 5101 if (atexit(perfMemory_exit_helper) != 0) { 5102 warning("os::init_2 atexit(perfMemory_exit_helper) failed"); 5103 } 5104 } 5105 5106 // initialize thread priority policy 5107 prio_init(); 5108 5109 if (!FLAG_IS_DEFAULT(AllocateHeapAt)) { 5110 set_coredump_filter(false /*largepages*/, true /*dax_shared*/); 5111 } 5112 return JNI_OK; 5113 } 5114 5115 // Mark the polling page as unreadable 5116 void os::make_polling_page_unreadable(void) { 5117 if (!guard_memory((char*)_polling_page, Linux::page_size())) { 5118 fatal("Could not disable polling page"); 5119 } 5120 } 5121 5122 // Mark the polling page as readable 5123 void os::make_polling_page_readable(void) { 5124 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) { 5125 fatal("Could not enable polling page"); 5126 } 5127 } 5128 5129 // older glibc versions don't have this macro (which expands to 5130 // an optimized bit-counting function) so we have to roll our own 5131 #ifndef CPU_COUNT 5132 5133 static int _cpu_count(const cpu_set_t* cpus) { 5134 int count = 0; 5135 // only look up to the number of configured processors 5136 for (int i = 0; i < os::processor_count(); i++) { 5137 if (CPU_ISSET(i, cpus)) { 5138 count++; 5139 } 5140 } 5141 return count; 5142 } 5143 5144 #define CPU_COUNT(cpus) _cpu_count(cpus) 5145 5146 #endif // CPU_COUNT 5147 5148 // Get the current number of available processors for this process. 5149 // This value can change at any time during a process's lifetime. 5150 // sched_getaffinity gives an accurate answer as it accounts for cpusets. 5151 // If it appears there may be more than 1024 processors then we do a 5152 // dynamic check - see 6515172 for details. 5153 // If anything goes wrong we fallback to returning the number of online 5154 // processors - which can be greater than the number available to the process. 5155 int os::Linux::active_processor_count() { 5156 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors 5157 cpu_set_t* cpus_p = &cpus; 5158 int cpus_size = sizeof(cpu_set_t); 5159 5160 int configured_cpus = os::processor_count(); // upper bound on available cpus 5161 int cpu_count = 0; 5162 5163 // old build platforms may not support dynamic cpu sets 5164 #ifdef CPU_ALLOC 5165 5166 // To enable easy testing of the dynamic path on different platforms we 5167 // introduce a diagnostic flag: UseCpuAllocPath 5168 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) { 5169 // kernel may use a mask bigger than cpu_set_t 5170 log_trace(os)("active_processor_count: using dynamic path %s" 5171 "- configured processors: %d", 5172 UseCpuAllocPath ? "(forced) " : "", 5173 configured_cpus); 5174 cpus_p = CPU_ALLOC(configured_cpus); 5175 if (cpus_p != NULL) { 5176 cpus_size = CPU_ALLOC_SIZE(configured_cpus); 5177 // zero it just to be safe 5178 CPU_ZERO_S(cpus_size, cpus_p); 5179 } 5180 else { 5181 // failed to allocate so fallback to online cpus 5182 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); 5183 log_trace(os)("active_processor_count: " 5184 "CPU_ALLOC failed (%s) - using " 5185 "online processor count: %d", 5186 os::strerror(errno), online_cpus); 5187 return online_cpus; 5188 } 5189 } 5190 else { 5191 log_trace(os)("active_processor_count: using static path - configured processors: %d", 5192 configured_cpus); 5193 } 5194 #else // CPU_ALLOC 5195 // these stubs won't be executed 5196 #define CPU_COUNT_S(size, cpus) -1 5197 #define CPU_FREE(cpus) 5198 5199 log_trace(os)("active_processor_count: only static path available - configured processors: %d", 5200 configured_cpus); 5201 #endif // CPU_ALLOC 5202 5203 // pid 0 means the current thread - which we have to assume represents the process 5204 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) { 5205 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5206 cpu_count = CPU_COUNT_S(cpus_size, cpus_p); 5207 } 5208 else { 5209 cpu_count = CPU_COUNT(cpus_p); 5210 } 5211 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count); 5212 } 5213 else { 5214 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN); 5215 warning("sched_getaffinity failed (%s)- using online processor count (%d) " 5216 "which may exceed available processors", os::strerror(errno), cpu_count); 5217 } 5218 5219 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5220 CPU_FREE(cpus_p); 5221 } 5222 5223 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check"); 5224 return cpu_count; 5225 } 5226 5227 // Determine the active processor count from one of 5228 // three different sources: 5229 // 5230 // 1. User option -XX:ActiveProcessorCount 5231 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN) 5232 // 3. extracted from cgroup cpu subsystem (shares and quotas) 5233 // 5234 // Option 1, if specified, will always override. 5235 // If the cgroup subsystem is active and configured, we 5236 // will return the min of the cgroup and option 2 results. 5237 // This is required since tools, such as numactl, that 5238 // alter cpu affinity do not update cgroup subsystem 5239 // cpuset configuration files. 5240 int os::active_processor_count() { 5241 // User has overridden the number of active processors 5242 if (ActiveProcessorCount > 0) { 5243 log_trace(os)("active_processor_count: " 5244 "active processor count set by user : %d", 5245 ActiveProcessorCount); 5246 return ActiveProcessorCount; 5247 } 5248 5249 int active_cpus; 5250 if (OSContainer::is_containerized()) { 5251 active_cpus = OSContainer::active_processor_count(); 5252 log_trace(os)("active_processor_count: determined by OSContainer: %d", 5253 active_cpus); 5254 } else { 5255 active_cpus = os::Linux::active_processor_count(); 5256 } 5257 5258 return active_cpus; 5259 } 5260 5261 uint os::processor_id() { 5262 const int id = Linux::sched_getcpu(); 5263 assert(id >= 0 && id < _processor_count, "Invalid processor id"); 5264 return (uint)id; 5265 } 5266 5267 void os::set_native_thread_name(const char *name) { 5268 if (Linux::_pthread_setname_np) { 5269 char buf [16]; // according to glibc manpage, 16 chars incl. '/0' 5270 snprintf(buf, sizeof(buf), "%s", name); 5271 buf[sizeof(buf) - 1] = '\0'; 5272 const int rc = Linux::_pthread_setname_np(pthread_self(), buf); 5273 // ERANGE should not happen; all other errors should just be ignored. 5274 assert(rc != ERANGE, "pthread_setname_np failed"); 5275 } 5276 } 5277 5278 bool os::distribute_processes(uint length, uint* distribution) { 5279 // Not yet implemented. 5280 return false; 5281 } 5282 5283 bool os::bind_to_processor(uint processor_id) { 5284 // Not yet implemented. 5285 return false; 5286 } 5287 5288 /// 5289 5290 void os::SuspendedThreadTask::internal_do_task() { 5291 if (do_suspend(_thread->osthread())) { 5292 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 5293 do_task(context); 5294 do_resume(_thread->osthread()); 5295 } 5296 } 5297 5298 //////////////////////////////////////////////////////////////////////////////// 5299 // debug support 5300 5301 bool os::find(address addr, outputStream* st) { 5302 Dl_info dlinfo; 5303 memset(&dlinfo, 0, sizeof(dlinfo)); 5304 if (dladdr(addr, &dlinfo) != 0) { 5305 st->print(PTR_FORMAT ": ", p2i(addr)); 5306 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 5307 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname, 5308 p2i(addr) - p2i(dlinfo.dli_saddr)); 5309 } else if (dlinfo.dli_fbase != NULL) { 5310 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase)); 5311 } else { 5312 st->print("<absolute address>"); 5313 } 5314 if (dlinfo.dli_fname != NULL) { 5315 st->print(" in %s", dlinfo.dli_fname); 5316 } 5317 if (dlinfo.dli_fbase != NULL) { 5318 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase)); 5319 } 5320 st->cr(); 5321 5322 if (Verbose) { 5323 // decode some bytes around the PC 5324 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 5325 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 5326 address lowest = (address) dlinfo.dli_sname; 5327 if (!lowest) lowest = (address) dlinfo.dli_fbase; 5328 if (begin < lowest) begin = lowest; 5329 Dl_info dlinfo2; 5330 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 5331 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 5332 end = (address) dlinfo2.dli_saddr; 5333 } 5334 Disassembler::decode(begin, end, st); 5335 } 5336 return true; 5337 } 5338 return false; 5339 } 5340 5341 //////////////////////////////////////////////////////////////////////////////// 5342 // misc 5343 5344 // This does not do anything on Linux. This is basically a hook for being 5345 // able to use structured exception handling (thread-local exception filters) 5346 // on, e.g., Win32. 5347 void 5348 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, 5349 JavaCallArguments* args, Thread* thread) { 5350 f(value, method, args, thread); 5351 } 5352 5353 void os::print_statistics() { 5354 } 5355 5356 bool os::message_box(const char* title, const char* message) { 5357 int i; 5358 fdStream err(defaultStream::error_fd()); 5359 for (i = 0; i < 78; i++) err.print_raw("="); 5360 err.cr(); 5361 err.print_raw_cr(title); 5362 for (i = 0; i < 78; i++) err.print_raw("-"); 5363 err.cr(); 5364 err.print_raw_cr(message); 5365 for (i = 0; i < 78; i++) err.print_raw("="); 5366 err.cr(); 5367 5368 char buf[16]; 5369 // Prevent process from exiting upon "read error" without consuming all CPU 5370 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 5371 5372 return buf[0] == 'y' || buf[0] == 'Y'; 5373 } 5374 5375 // Is a (classpath) directory empty? 5376 bool os::dir_is_empty(const char* path) { 5377 DIR *dir = NULL; 5378 struct dirent *ptr; 5379 5380 dir = opendir(path); 5381 if (dir == NULL) return true; 5382 5383 // Scan the directory 5384 bool result = true; 5385 while (result && (ptr = readdir(dir)) != NULL) { 5386 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 5387 result = false; 5388 } 5389 } 5390 closedir(dir); 5391 return result; 5392 } 5393 5394 // This code originates from JDK's sysOpen and open64_w 5395 // from src/solaris/hpi/src/system_md.c 5396 5397 int os::open(const char *path, int oflag, int mode) { 5398 if (strlen(path) > MAX_PATH - 1) { 5399 errno = ENAMETOOLONG; 5400 return -1; 5401 } 5402 5403 // All file descriptors that are opened in the Java process and not 5404 // specifically destined for a subprocess should have the close-on-exec 5405 // flag set. If we don't set it, then careless 3rd party native code 5406 // might fork and exec without closing all appropriate file descriptors 5407 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in 5408 // turn might: 5409 // 5410 // - cause end-of-file to fail to be detected on some file 5411 // descriptors, resulting in mysterious hangs, or 5412 // 5413 // - might cause an fopen in the subprocess to fail on a system 5414 // suffering from bug 1085341. 5415 // 5416 // (Yes, the default setting of the close-on-exec flag is a Unix 5417 // design flaw) 5418 // 5419 // See: 5420 // 1085341: 32-bit stdio routines should support file descriptors >255 5421 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 5422 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 5423 // 5424 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open(). 5425 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor 5426 // because it saves a system call and removes a small window where the flag 5427 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored 5428 // and we fall back to using FD_CLOEXEC (see below). 5429 #ifdef O_CLOEXEC 5430 oflag |= O_CLOEXEC; 5431 #endif 5432 5433 int fd = ::open64(path, oflag, mode); 5434 if (fd == -1) return -1; 5435 5436 //If the open succeeded, the file might still be a directory 5437 { 5438 struct stat64 buf64; 5439 int ret = ::fstat64(fd, &buf64); 5440 int st_mode = buf64.st_mode; 5441 5442 if (ret != -1) { 5443 if ((st_mode & S_IFMT) == S_IFDIR) { 5444 errno = EISDIR; 5445 ::close(fd); 5446 return -1; 5447 } 5448 } else { 5449 ::close(fd); 5450 return -1; 5451 } 5452 } 5453 5454 #ifdef FD_CLOEXEC 5455 // Validate that the use of the O_CLOEXEC flag on open above worked. 5456 // With recent kernels, we will perform this check exactly once. 5457 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0; 5458 if (!O_CLOEXEC_is_known_to_work) { 5459 int flags = ::fcntl(fd, F_GETFD); 5460 if (flags != -1) { 5461 if ((flags & FD_CLOEXEC) != 0) 5462 O_CLOEXEC_is_known_to_work = 1; 5463 else 5464 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 5465 } 5466 } 5467 #endif 5468 5469 return fd; 5470 } 5471 5472 5473 // create binary file, rewriting existing file if required 5474 int os::create_binary_file(const char* path, bool rewrite_existing) { 5475 int oflags = O_WRONLY | O_CREAT; 5476 if (!rewrite_existing) { 5477 oflags |= O_EXCL; 5478 } 5479 return ::open64(path, oflags, S_IREAD | S_IWRITE); 5480 } 5481 5482 // return current position of file pointer 5483 jlong os::current_file_offset(int fd) { 5484 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR); 5485 } 5486 5487 // move file pointer to the specified offset 5488 jlong os::seek_to_file_offset(int fd, jlong offset) { 5489 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET); 5490 } 5491 5492 // This code originates from JDK's sysAvailable 5493 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 5494 5495 int os::available(int fd, jlong *bytes) { 5496 jlong cur, end; 5497 int mode; 5498 struct stat64 buf64; 5499 5500 if (::fstat64(fd, &buf64) >= 0) { 5501 mode = buf64.st_mode; 5502 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 5503 int n; 5504 if (::ioctl(fd, FIONREAD, &n) >= 0) { 5505 *bytes = n; 5506 return 1; 5507 } 5508 } 5509 } 5510 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) { 5511 return 0; 5512 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) { 5513 return 0; 5514 } else if (::lseek64(fd, cur, SEEK_SET) == -1) { 5515 return 0; 5516 } 5517 *bytes = end - cur; 5518 return 1; 5519 } 5520 5521 // Map a block of memory. 5522 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 5523 char *addr, size_t bytes, bool read_only, 5524 bool allow_exec) { 5525 int prot; 5526 int flags = MAP_PRIVATE; 5527 5528 if (read_only) { 5529 prot = PROT_READ; 5530 } else { 5531 prot = PROT_READ | PROT_WRITE; 5532 } 5533 5534 if (allow_exec) { 5535 prot |= PROT_EXEC; 5536 } 5537 5538 if (addr != NULL) { 5539 flags |= MAP_FIXED; 5540 } 5541 5542 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 5543 fd, file_offset); 5544 if (mapped_address == MAP_FAILED) { 5545 return NULL; 5546 } 5547 return mapped_address; 5548 } 5549 5550 5551 // Remap a block of memory. 5552 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 5553 char *addr, size_t bytes, bool read_only, 5554 bool allow_exec) { 5555 // same as map_memory() on this OS 5556 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 5557 allow_exec); 5558 } 5559 5560 5561 // Unmap a block of memory. 5562 bool os::pd_unmap_memory(char* addr, size_t bytes) { 5563 return munmap(addr, bytes) == 0; 5564 } 5565 5566 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); 5567 5568 static jlong fast_cpu_time(Thread *thread) { 5569 clockid_t clockid; 5570 int rc = os::Linux::pthread_getcpuclockid(thread->osthread()->pthread_id(), 5571 &clockid); 5572 if (rc == 0) { 5573 return os::Linux::fast_thread_cpu_time(clockid); 5574 } else { 5575 // It's possible to encounter a terminated native thread that failed 5576 // to detach itself from the VM - which should result in ESRCH. 5577 assert_status(rc == ESRCH, rc, "pthread_getcpuclockid failed"); 5578 return -1; 5579 } 5580 } 5581 5582 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 5583 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 5584 // of a thread. 5585 // 5586 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 5587 // the fast estimate available on the platform. 5588 5589 jlong os::current_thread_cpu_time() { 5590 if (os::Linux::supports_fast_thread_cpu_time()) { 5591 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5592 } else { 5593 // return user + sys since the cost is the same 5594 return slow_thread_cpu_time(Thread::current(), true /* user + sys */); 5595 } 5596 } 5597 5598 jlong os::thread_cpu_time(Thread* thread) { 5599 // consistent with what current_thread_cpu_time() returns 5600 if (os::Linux::supports_fast_thread_cpu_time()) { 5601 return fast_cpu_time(thread); 5602 } else { 5603 return slow_thread_cpu_time(thread, true /* user + sys */); 5604 } 5605 } 5606 5607 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 5608 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5609 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5610 } else { 5611 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); 5612 } 5613 } 5614 5615 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5616 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5617 return fast_cpu_time(thread); 5618 } else { 5619 return slow_thread_cpu_time(thread, user_sys_cpu_time); 5620 } 5621 } 5622 5623 // -1 on error. 5624 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5625 pid_t tid = thread->osthread()->thread_id(); 5626 char *s; 5627 char stat[2048]; 5628 int statlen; 5629 char proc_name[64]; 5630 int count; 5631 long sys_time, user_time; 5632 char cdummy; 5633 int idummy; 5634 long ldummy; 5635 FILE *fp; 5636 5637 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid); 5638 fp = fopen(proc_name, "r"); 5639 if (fp == NULL) return -1; 5640 statlen = fread(stat, 1, 2047, fp); 5641 stat[statlen] = '\0'; 5642 fclose(fp); 5643 5644 // Skip pid and the command string. Note that we could be dealing with 5645 // weird command names, e.g. user could decide to rename java launcher 5646 // to "java 1.4.2 :)", then the stat file would look like 5647 // 1234 (java 1.4.2 :)) R ... ... 5648 // We don't really need to know the command string, just find the last 5649 // occurrence of ")" and then start parsing from there. See bug 4726580. 5650 s = strrchr(stat, ')'); 5651 if (s == NULL) return -1; 5652 5653 // Skip blank chars 5654 do { s++; } while (s && isspace(*s)); 5655 5656 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", 5657 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy, 5658 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, 5659 &user_time, &sys_time); 5660 if (count != 13) return -1; 5661 if (user_sys_cpu_time) { 5662 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); 5663 } else { 5664 return (jlong)user_time * (1000000000 / clock_tics_per_sec); 5665 } 5666 } 5667 5668 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5669 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5670 info_ptr->may_skip_backward = false; // elapsed time not wall time 5671 info_ptr->may_skip_forward = false; // elapsed time not wall time 5672 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5673 } 5674 5675 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5676 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5677 info_ptr->may_skip_backward = false; // elapsed time not wall time 5678 info_ptr->may_skip_forward = false; // elapsed time not wall time 5679 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5680 } 5681 5682 bool os::is_thread_cpu_time_supported() { 5683 return true; 5684 } 5685 5686 // System loadavg support. Returns -1 if load average cannot be obtained. 5687 // Linux doesn't yet have a (official) notion of processor sets, 5688 // so just return the system wide load average. 5689 int os::loadavg(double loadavg[], int nelem) { 5690 return ::getloadavg(loadavg, nelem); 5691 } 5692 5693 void os::pause() { 5694 char filename[MAX_PATH]; 5695 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 5696 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile); 5697 } else { 5698 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 5699 } 5700 5701 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 5702 if (fd != -1) { 5703 struct stat buf; 5704 ::close(fd); 5705 while (::stat(filename, &buf) == 0) { 5706 (void)::poll(NULL, 0, 100); 5707 } 5708 } else { 5709 jio_fprintf(stderr, 5710 "Could not open pause file '%s', continuing immediately.\n", filename); 5711 } 5712 } 5713 5714 extern char** environ; 5715 5716 // Run the specified command in a separate process. Return its exit value, 5717 // or -1 on failure (e.g. can't fork a new process). 5718 // Unlike system(), this function can be called from signal handler. It 5719 // doesn't block SIGINT et al. 5720 int os::fork_and_exec(char* cmd) { 5721 const char * argv[4] = {"sh", "-c", cmd, NULL}; 5722 5723 pid_t pid = fork(); 5724 5725 if (pid < 0) { 5726 // fork failed 5727 return -1; 5728 5729 } else if (pid == 0) { 5730 // child process 5731 5732 execve("/bin/sh", (char* const*)argv, environ); 5733 5734 // execve failed 5735 _exit(-1); 5736 5737 } else { 5738 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 5739 // care about the actual exit code, for now. 5740 5741 int status; 5742 5743 // Wait for the child process to exit. This returns immediately if 5744 // the child has already exited. */ 5745 while (waitpid(pid, &status, 0) < 0) { 5746 switch (errno) { 5747 case ECHILD: return 0; 5748 case EINTR: break; 5749 default: return -1; 5750 } 5751 } 5752 5753 if (WIFEXITED(status)) { 5754 // The child exited normally; get its exit code. 5755 return WEXITSTATUS(status); 5756 } else if (WIFSIGNALED(status)) { 5757 // The child exited because of a signal 5758 // The best value to return is 0x80 + signal number, 5759 // because that is what all Unix shells do, and because 5760 // it allows callers to distinguish between process exit and 5761 // process death by signal. 5762 return 0x80 + WTERMSIG(status); 5763 } else { 5764 // Unknown exit code; pass it through 5765 return status; 5766 } 5767 } 5768 } 5769 5770 // Get the default path to the core file 5771 // Returns the length of the string 5772 int os::get_core_path(char* buffer, size_t bufferSize) { 5773 /* 5774 * Max length of /proc/sys/kernel/core_pattern is 128 characters. 5775 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt 5776 */ 5777 const int core_pattern_len = 129; 5778 char core_pattern[core_pattern_len] = {0}; 5779 5780 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY); 5781 if (core_pattern_file == -1) { 5782 return -1; 5783 } 5784 5785 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len); 5786 ::close(core_pattern_file); 5787 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') { 5788 return -1; 5789 } 5790 if (core_pattern[ret-1] == '\n') { 5791 core_pattern[ret-1] = '\0'; 5792 } else { 5793 core_pattern[ret] = '\0'; 5794 } 5795 5796 // Replace the %p in the core pattern with the process id. NOTE: we do this 5797 // only if the pattern doesn't start with "|", and we support only one %p in 5798 // the pattern. 5799 char *pid_pos = strstr(core_pattern, "%p"); 5800 const char* tail = (pid_pos != NULL) ? (pid_pos + 2) : ""; // skip over the "%p" 5801 int written; 5802 5803 if (core_pattern[0] == '/') { 5804 if (pid_pos != NULL) { 5805 *pid_pos = '\0'; 5806 written = jio_snprintf(buffer, bufferSize, "%s%d%s", core_pattern, 5807 current_process_id(), tail); 5808 } else { 5809 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern); 5810 } 5811 } else { 5812 char cwd[PATH_MAX]; 5813 5814 const char* p = get_current_directory(cwd, PATH_MAX); 5815 if (p == NULL) { 5816 return -1; 5817 } 5818 5819 if (core_pattern[0] == '|') { 5820 written = jio_snprintf(buffer, bufferSize, 5821 "\"%s\" (or dumping to %s/core.%d)", 5822 &core_pattern[1], p, current_process_id()); 5823 } else if (pid_pos != NULL) { 5824 *pid_pos = '\0'; 5825 written = jio_snprintf(buffer, bufferSize, "%s/%s%d%s", p, core_pattern, 5826 current_process_id(), tail); 5827 } else { 5828 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern); 5829 } 5830 } 5831 5832 if (written < 0) { 5833 return -1; 5834 } 5835 5836 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) { 5837 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY); 5838 5839 if (core_uses_pid_file != -1) { 5840 char core_uses_pid = 0; 5841 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1); 5842 ::close(core_uses_pid_file); 5843 5844 if (core_uses_pid == '1') { 5845 jio_snprintf(buffer + written, bufferSize - written, 5846 ".%d", current_process_id()); 5847 } 5848 } 5849 } 5850 5851 return strlen(buffer); 5852 } 5853 5854 bool os::start_debugging(char *buf, int buflen) { 5855 int len = (int)strlen(buf); 5856 char *p = &buf[len]; 5857 5858 jio_snprintf(p, buflen-len, 5859 "\n\n" 5860 "Do you want to debug the problem?\n\n" 5861 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n" 5862 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n" 5863 "Otherwise, press RETURN to abort...", 5864 os::current_process_id(), os::current_process_id(), 5865 os::current_thread_id(), os::current_thread_id()); 5866 5867 bool yes = os::message_box("Unexpected Error", buf); 5868 5869 if (yes) { 5870 // yes, user asked VM to launch debugger 5871 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d", 5872 os::current_process_id(), os::current_process_id()); 5873 5874 os::fork_and_exec(buf); 5875 yes = false; 5876 } 5877 return yes; 5878 } 5879 5880 5881 // Java/Compiler thread: 5882 // 5883 // Low memory addresses 5884 // P0 +------------------------+ 5885 // | |\ Java thread created by VM does not have glibc 5886 // | glibc guard page | - guard page, attached Java thread usually has 5887 // | |/ 1 glibc guard page. 5888 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 5889 // | |\ 5890 // | HotSpot Guard Pages | - red, yellow and reserved pages 5891 // | |/ 5892 // +------------------------+ JavaThread::stack_reserved_zone_base() 5893 // | |\ 5894 // | Normal Stack | - 5895 // | |/ 5896 // P2 +------------------------+ Thread::stack_base() 5897 // 5898 // Non-Java thread: 5899 // 5900 // Low memory addresses 5901 // P0 +------------------------+ 5902 // | |\ 5903 // | glibc guard page | - usually 1 page 5904 // | |/ 5905 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 5906 // | |\ 5907 // | Normal Stack | - 5908 // | |/ 5909 // P2 +------------------------+ Thread::stack_base() 5910 // 5911 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size 5912 // returned from pthread_attr_getstack(). 5913 // ** Due to NPTL implementation error, linux takes the glibc guard page out 5914 // of the stack size given in pthread_attr. We work around this for 5915 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.) 5916 // 5917 #ifndef ZERO 5918 static void current_stack_region(address * bottom, size_t * size) { 5919 if (os::is_primordial_thread()) { 5920 // primordial thread needs special handling because pthread_getattr_np() 5921 // may return bogus value. 5922 *bottom = os::Linux::initial_thread_stack_bottom(); 5923 *size = os::Linux::initial_thread_stack_size(); 5924 } else { 5925 pthread_attr_t attr; 5926 5927 int rslt = pthread_getattr_np(pthread_self(), &attr); 5928 5929 // JVM needs to know exact stack location, abort if it fails 5930 if (rslt != 0) { 5931 if (rslt == ENOMEM) { 5932 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); 5933 } else { 5934 fatal("pthread_getattr_np failed with error = %d", rslt); 5935 } 5936 } 5937 5938 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { 5939 fatal("Cannot locate current stack attributes!"); 5940 } 5941 5942 // Work around NPTL stack guard error. 5943 size_t guard_size = 0; 5944 rslt = pthread_attr_getguardsize(&attr, &guard_size); 5945 if (rslt != 0) { 5946 fatal("pthread_attr_getguardsize failed with error = %d", rslt); 5947 } 5948 *bottom += guard_size; 5949 *size -= guard_size; 5950 5951 pthread_attr_destroy(&attr); 5952 5953 } 5954 assert(os::current_stack_pointer() >= *bottom && 5955 os::current_stack_pointer() < *bottom + *size, "just checking"); 5956 } 5957 5958 address os::current_stack_base() { 5959 address bottom; 5960 size_t size; 5961 current_stack_region(&bottom, &size); 5962 return (bottom + size); 5963 } 5964 5965 size_t os::current_stack_size() { 5966 // This stack size includes the usable stack and HotSpot guard pages 5967 // (for the threads that have Hotspot guard pages). 5968 address bottom; 5969 size_t size; 5970 current_stack_region(&bottom, &size); 5971 return size; 5972 } 5973 #endif 5974 5975 static inline struct timespec get_mtime(const char* filename) { 5976 struct stat st; 5977 int ret = os::stat(filename, &st); 5978 assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno)); 5979 return st.st_mtim; 5980 } 5981 5982 int os::compare_file_modified_times(const char* file1, const char* file2) { 5983 struct timespec filetime1 = get_mtime(file1); 5984 struct timespec filetime2 = get_mtime(file2); 5985 int diff = filetime1.tv_sec - filetime2.tv_sec; 5986 if (diff == 0) { 5987 return filetime1.tv_nsec - filetime2.tv_nsec; 5988 } 5989 return diff; 5990 } 5991 5992 /////////////// Unit tests /////////////// 5993 5994 #ifndef PRODUCT 5995 5996 #define test_log(...) \ 5997 do { \ 5998 if (VerboseInternalVMTests) { \ 5999 tty->print_cr(__VA_ARGS__); \ 6000 tty->flush(); \ 6001 } \ 6002 } while (false) 6003 6004 class TestReserveMemorySpecial : AllStatic { 6005 public: 6006 static void small_page_write(void* addr, size_t size) { 6007 size_t page_size = os::vm_page_size(); 6008 6009 char* end = (char*)addr + size; 6010 for (char* p = (char*)addr; p < end; p += page_size) { 6011 *p = 1; 6012 } 6013 } 6014 6015 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) { 6016 if (!UseHugeTLBFS) { 6017 return; 6018 } 6019 6020 test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size); 6021 6022 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false); 6023 6024 if (addr != NULL) { 6025 small_page_write(addr, size); 6026 6027 os::Linux::release_memory_special_huge_tlbfs(addr, size); 6028 } 6029 } 6030 6031 static void test_reserve_memory_special_huge_tlbfs_only() { 6032 if (!UseHugeTLBFS) { 6033 return; 6034 } 6035 6036 size_t lp = os::large_page_size(); 6037 6038 for (size_t size = lp; size <= lp * 10; size += lp) { 6039 test_reserve_memory_special_huge_tlbfs_only(size); 6040 } 6041 } 6042 6043 static void test_reserve_memory_special_huge_tlbfs_mixed() { 6044 size_t lp = os::large_page_size(); 6045 size_t ag = os::vm_allocation_granularity(); 6046 6047 // sizes to test 6048 const size_t sizes[] = { 6049 lp, lp + ag, lp + lp / 2, lp * 2, 6050 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2, 6051 lp * 10, lp * 10 + lp / 2 6052 }; 6053 const int num_sizes = sizeof(sizes) / sizeof(size_t); 6054 6055 // For each size/alignment combination, we test three scenarios: 6056 // 1) with req_addr == NULL 6057 // 2) with a non-null req_addr at which we expect to successfully allocate 6058 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we 6059 // expect the allocation to either fail or to ignore req_addr 6060 6061 // Pre-allocate two areas; they shall be as large as the largest allocation 6062 // and aligned to the largest alignment we will be testing. 6063 const size_t mapping_size = sizes[num_sizes - 1] * 2; 6064 char* const mapping1 = (char*) ::mmap(NULL, mapping_size, 6065 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 6066 -1, 0); 6067 assert(mapping1 != MAP_FAILED, "should work"); 6068 6069 char* const mapping2 = (char*) ::mmap(NULL, mapping_size, 6070 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 6071 -1, 0); 6072 assert(mapping2 != MAP_FAILED, "should work"); 6073 6074 // Unmap the first mapping, but leave the second mapping intact: the first 6075 // mapping will serve as a value for a "good" req_addr (case 2). The second 6076 // mapping, still intact, as "bad" req_addr (case 3). 6077 ::munmap(mapping1, mapping_size); 6078 6079 // Case 1 6080 test_log("%s, req_addr NULL:", __FUNCTION__); 6081 test_log("size align result"); 6082 6083 for (int i = 0; i < num_sizes; i++) { 6084 const size_t size = sizes[i]; 6085 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6086 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false); 6087 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s", 6088 size, alignment, p2i(p), (p != NULL ? "" : "(failed)")); 6089 if (p != NULL) { 6090 assert(is_aligned(p, alignment), "must be"); 6091 small_page_write(p, size); 6092 os::Linux::release_memory_special_huge_tlbfs(p, size); 6093 } 6094 } 6095 } 6096 6097 // Case 2 6098 test_log("%s, req_addr non-NULL:", __FUNCTION__); 6099 test_log("size align req_addr result"); 6100 6101 for (int i = 0; i < num_sizes; i++) { 6102 const size_t size = sizes[i]; 6103 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6104 char* const req_addr = align_up(mapping1, alignment); 6105 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 6106 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 6107 size, alignment, p2i(req_addr), p2i(p), 6108 ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)"))); 6109 if (p != NULL) { 6110 assert(p == req_addr, "must be"); 6111 small_page_write(p, size); 6112 os::Linux::release_memory_special_huge_tlbfs(p, size); 6113 } 6114 } 6115 } 6116 6117 // Case 3 6118 test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__); 6119 test_log("size align req_addr result"); 6120 6121 for (int i = 0; i < num_sizes; i++) { 6122 const size_t size = sizes[i]; 6123 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6124 char* const req_addr = align_up(mapping2, alignment); 6125 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 6126 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 6127 size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)"))); 6128 // as the area around req_addr contains already existing mappings, the API should always 6129 // return NULL (as per contract, it cannot return another address) 6130 assert(p == NULL, "must be"); 6131 } 6132 } 6133 6134 ::munmap(mapping2, mapping_size); 6135 6136 } 6137 6138 static void test_reserve_memory_special_huge_tlbfs() { 6139 if (!UseHugeTLBFS) { 6140 return; 6141 } 6142 6143 test_reserve_memory_special_huge_tlbfs_only(); 6144 test_reserve_memory_special_huge_tlbfs_mixed(); 6145 } 6146 6147 static void test_reserve_memory_special_shm(size_t size, size_t alignment) { 6148 if (!UseSHM) { 6149 return; 6150 } 6151 6152 test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment); 6153 6154 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false); 6155 6156 if (addr != NULL) { 6157 assert(is_aligned(addr, alignment), "Check"); 6158 assert(is_aligned(addr, os::large_page_size()), "Check"); 6159 6160 small_page_write(addr, size); 6161 6162 os::Linux::release_memory_special_shm(addr, size); 6163 } 6164 } 6165 6166 static void test_reserve_memory_special_shm() { 6167 size_t lp = os::large_page_size(); 6168 size_t ag = os::vm_allocation_granularity(); 6169 6170 for (size_t size = ag; size < lp * 3; size += ag) { 6171 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6172 test_reserve_memory_special_shm(size, alignment); 6173 } 6174 } 6175 } 6176 6177 static void test() { 6178 test_reserve_memory_special_huge_tlbfs(); 6179 test_reserve_memory_special_shm(); 6180 } 6181 }; 6182 6183 void TestReserveMemorySpecial_test() { 6184 TestReserveMemorySpecial::test(); 6185 } 6186 6187 #endif