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 set_boot_path('/', ':'); 371 } 372 373 // Where to look for native libraries. 374 // 375 // Note: Due to a legacy implementation, most of the library path 376 // is set in the launcher. This was to accomodate linking restrictions 377 // on legacy Linux implementations (which are no longer supported). 378 // Eventually, all the library path setting will be done here. 379 // 380 // However, to prevent the proliferation of improperly built native 381 // libraries, the new path component /usr/java/packages is added here. 382 // Eventually, all the library path setting will be done here. 383 { 384 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 385 // should always exist (until the legacy problem cited above is 386 // addressed). 387 const char *v = ::getenv("LD_LIBRARY_PATH"); 388 const char *v_colon = ":"; 389 if (v == NULL) { v = ""; v_colon = ""; } 390 // That's +1 for the colon and +1 for the trailing '\0'. 391 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 392 strlen(v) + 1 + 393 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1, 394 mtInternal); 395 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon); 396 Arguments::set_library_path(ld_library_path); 397 FREE_C_HEAP_ARRAY(char, ld_library_path); 398 } 399 400 // Extensions directories. 401 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 402 Arguments::set_ext_dirs(buf); 403 404 FREE_C_HEAP_ARRAY(char, buf); 405 406 #undef DEFAULT_LIBPATH 407 #undef SYS_EXT_DIR 408 #undef EXTENSIONS_DIR 409 } 410 411 //////////////////////////////////////////////////////////////////////////////// 412 // breakpoint support 413 414 void os::breakpoint() { 415 BREAKPOINT; 416 } 417 418 extern "C" void breakpoint() { 419 // use debugger to set breakpoint here 420 } 421 422 //////////////////////////////////////////////////////////////////////////////// 423 // signal support 424 425 debug_only(static bool signal_sets_initialized = false); 426 static sigset_t unblocked_sigs, vm_sigs; 427 428 void os::Linux::signal_sets_init() { 429 // Should also have an assertion stating we are still single-threaded. 430 assert(!signal_sets_initialized, "Already initialized"); 431 // Fill in signals that are necessarily unblocked for all threads in 432 // the VM. Currently, we unblock the following signals: 433 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 434 // by -Xrs (=ReduceSignalUsage)); 435 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 436 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 437 // the dispositions or masks wrt these signals. 438 // Programs embedding the VM that want to use the above signals for their 439 // own purposes must, at this time, use the "-Xrs" option to prevent 440 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 441 // (See bug 4345157, and other related bugs). 442 // In reality, though, unblocking these signals is really a nop, since 443 // these signals are not blocked by default. 444 sigemptyset(&unblocked_sigs); 445 sigaddset(&unblocked_sigs, SIGILL); 446 sigaddset(&unblocked_sigs, SIGSEGV); 447 sigaddset(&unblocked_sigs, SIGBUS); 448 sigaddset(&unblocked_sigs, SIGFPE); 449 #if defined(PPC64) 450 sigaddset(&unblocked_sigs, SIGTRAP); 451 #endif 452 sigaddset(&unblocked_sigs, SR_signum); 453 454 if (!ReduceSignalUsage) { 455 if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 456 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 457 } 458 if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 459 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 460 } 461 if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 462 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 463 } 464 } 465 // Fill in signals that are blocked by all but the VM thread. 466 sigemptyset(&vm_sigs); 467 if (!ReduceSignalUsage) { 468 sigaddset(&vm_sigs, BREAK_SIGNAL); 469 } 470 debug_only(signal_sets_initialized = true); 471 472 } 473 474 // These are signals that are unblocked while a thread is running Java. 475 // (For some reason, they get blocked by default.) 476 sigset_t* os::Linux::unblocked_signals() { 477 assert(signal_sets_initialized, "Not initialized"); 478 return &unblocked_sigs; 479 } 480 481 // These are the signals that are blocked while a (non-VM) thread is 482 // running Java. Only the VM thread handles these signals. 483 sigset_t* os::Linux::vm_signals() { 484 assert(signal_sets_initialized, "Not initialized"); 485 return &vm_sigs; 486 } 487 488 void os::Linux::hotspot_sigmask(Thread* thread) { 489 490 //Save caller's signal mask before setting VM signal mask 491 sigset_t caller_sigmask; 492 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 493 494 OSThread* osthread = thread->osthread(); 495 osthread->set_caller_sigmask(caller_sigmask); 496 497 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL); 498 499 if (!ReduceSignalUsage) { 500 if (thread->is_VM_thread()) { 501 // Only the VM thread handles BREAK_SIGNAL ... 502 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 503 } else { 504 // ... all other threads block BREAK_SIGNAL 505 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 506 } 507 } 508 } 509 510 ////////////////////////////////////////////////////////////////////////////// 511 // detecting pthread library 512 513 void os::Linux::libpthread_init() { 514 // Save glibc and pthread version strings. 515 #if !defined(_CS_GNU_LIBC_VERSION) || \ 516 !defined(_CS_GNU_LIBPTHREAD_VERSION) 517 #error "glibc too old (< 2.3.2)" 518 #endif 519 520 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); 521 assert(n > 0, "cannot retrieve glibc version"); 522 char *str = (char *)malloc(n, mtInternal); 523 confstr(_CS_GNU_LIBC_VERSION, str, n); 524 os::Linux::set_glibc_version(str); 525 526 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); 527 assert(n > 0, "cannot retrieve pthread version"); 528 str = (char *)malloc(n, mtInternal); 529 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); 530 os::Linux::set_libpthread_version(str); 531 } 532 533 ///////////////////////////////////////////////////////////////////////////// 534 // thread stack expansion 535 536 // os::Linux::manually_expand_stack() takes care of expanding the thread 537 // stack. Note that this is normally not needed: pthread stacks allocate 538 // thread stack using mmap() without MAP_NORESERVE, so the stack is already 539 // committed. Therefore it is not necessary to expand the stack manually. 540 // 541 // Manually expanding the stack was historically needed on LinuxThreads 542 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays 543 // it is kept to deal with very rare corner cases: 544 // 545 // For one, user may run the VM on an own implementation of threads 546 // whose stacks are - like the old LinuxThreads - implemented using 547 // mmap(MAP_GROWSDOWN). 548 // 549 // Also, this coding may be needed if the VM is running on the primordial 550 // thread. Normally we avoid running on the primordial thread; however, 551 // user may still invoke the VM on the primordial thread. 552 // 553 // The following historical comment describes the details about running 554 // on a thread stack allocated with mmap(MAP_GROWSDOWN): 555 556 557 // Force Linux kernel to expand current thread stack. If "bottom" is close 558 // to the stack guard, caller should block all signals. 559 // 560 // MAP_GROWSDOWN: 561 // A special mmap() flag that is used to implement thread stacks. It tells 562 // kernel that the memory region should extend downwards when needed. This 563 // allows early versions of LinuxThreads to only mmap the first few pages 564 // when creating a new thread. Linux kernel will automatically expand thread 565 // stack as needed (on page faults). 566 // 567 // However, because the memory region of a MAP_GROWSDOWN stack can grow on 568 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN 569 // region, it's hard to tell if the fault is due to a legitimate stack 570 // access or because of reading/writing non-exist memory (e.g. buffer 571 // overrun). As a rule, if the fault happens below current stack pointer, 572 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the 573 // application (see Linux kernel fault.c). 574 // 575 // This Linux feature can cause SIGSEGV when VM bangs thread stack for 576 // stack overflow detection. 577 // 578 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do 579 // not use MAP_GROWSDOWN. 580 // 581 // To get around the problem and allow stack banging on Linux, we need to 582 // manually expand thread stack after receiving the SIGSEGV. 583 // 584 // There are two ways to expand thread stack to address "bottom", we used 585 // both of them in JVM before 1.5: 586 // 1. adjust stack pointer first so that it is below "bottom", and then 587 // touch "bottom" 588 // 2. mmap() the page in question 589 // 590 // Now alternate signal stack is gone, it's harder to use 2. For instance, 591 // if current sp is already near the lower end of page 101, and we need to 592 // call mmap() to map page 100, it is possible that part of the mmap() frame 593 // will be placed in page 100. When page 100 is mapped, it is zero-filled. 594 // That will destroy the mmap() frame and cause VM to crash. 595 // 596 // The following code works by adjusting sp first, then accessing the "bottom" 597 // page to force a page fault. Linux kernel will then automatically expand the 598 // stack mapping. 599 // 600 // _expand_stack_to() assumes its frame size is less than page size, which 601 // should always be true if the function is not inlined. 602 603 static void NOINLINE _expand_stack_to(address bottom) { 604 address sp; 605 size_t size; 606 volatile char *p; 607 608 // Adjust bottom to point to the largest address within the same page, it 609 // gives us a one-page buffer if alloca() allocates slightly more memory. 610 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size()); 611 bottom += os::Linux::page_size() - 1; 612 613 // sp might be slightly above current stack pointer; if that's the case, we 614 // will alloca() a little more space than necessary, which is OK. Don't use 615 // os::current_stack_pointer(), as its result can be slightly below current 616 // stack pointer, causing us to not alloca enough to reach "bottom". 617 sp = (address)&sp; 618 619 if (sp > bottom) { 620 size = sp - bottom; 621 p = (volatile char *)alloca(size); 622 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); 623 p[0] = '\0'; 624 } 625 } 626 627 void os::Linux::expand_stack_to(address bottom) { 628 _expand_stack_to(bottom); 629 } 630 631 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) { 632 assert(t!=NULL, "just checking"); 633 assert(t->osthread()->expanding_stack(), "expand should be set"); 634 assert(t->stack_base() != NULL, "stack_base was not initialized"); 635 636 if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) { 637 sigset_t mask_all, old_sigset; 638 sigfillset(&mask_all); 639 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); 640 _expand_stack_to(addr); 641 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); 642 return true; 643 } 644 return false; 645 } 646 647 ////////////////////////////////////////////////////////////////////////////// 648 // create new thread 649 650 // Thread start routine for all newly created threads 651 static void *thread_native_entry(Thread *thread) { 652 // Try to randomize the cache line index of hot stack frames. 653 // This helps when threads of the same stack traces evict each other's 654 // cache lines. The threads can be either from the same JVM instance, or 655 // from different JVM instances. The benefit is especially true for 656 // processors with hyperthreading technology. 657 static int counter = 0; 658 int pid = os::current_process_id(); 659 alloca(((pid ^ counter++) & 7) * 128); 660 661 thread->initialize_thread_current(); 662 663 OSThread* osthread = thread->osthread(); 664 Monitor* sync = osthread->startThread_lock(); 665 666 osthread->set_thread_id(os::current_thread_id()); 667 668 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 669 os::current_thread_id(), (uintx) pthread_self()); 670 671 if (UseNUMA) { 672 int lgrp_id = os::numa_get_group_id(); 673 if (lgrp_id != -1) { 674 thread->set_lgrp_id(lgrp_id); 675 } 676 } 677 // initialize signal mask for this thread 678 os::Linux::hotspot_sigmask(thread); 679 680 // initialize floating point control register 681 os::Linux::init_thread_fpu_state(); 682 683 // handshaking with parent thread 684 { 685 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 686 687 // notify parent thread 688 osthread->set_state(INITIALIZED); 689 sync->notify_all(); 690 691 // wait until os::start_thread() 692 while (osthread->get_state() == INITIALIZED) { 693 sync->wait(Mutex::_no_safepoint_check_flag); 694 } 695 } 696 697 // call one more level start routine 698 thread->run(); 699 700 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 701 os::current_thread_id(), (uintx) pthread_self()); 702 703 // If a thread has not deleted itself ("delete this") as part of its 704 // termination sequence, we have to ensure thread-local-storage is 705 // cleared before we actually terminate. No threads should ever be 706 // deleted asynchronously with respect to their termination. 707 if (Thread::current_or_null_safe() != NULL) { 708 assert(Thread::current_or_null_safe() == thread, "current thread is wrong"); 709 thread->clear_thread_current(); 710 } 711 712 return 0; 713 } 714 715 bool os::create_thread(Thread* thread, ThreadType thr_type, 716 size_t req_stack_size) { 717 assert(thread->osthread() == NULL, "caller responsible"); 718 719 // Allocate the OSThread object 720 OSThread* osthread = new OSThread(NULL, NULL); 721 if (osthread == NULL) { 722 return false; 723 } 724 725 // set the correct thread state 726 osthread->set_thread_type(thr_type); 727 728 // Initial state is ALLOCATED but not INITIALIZED 729 osthread->set_state(ALLOCATED); 730 731 thread->set_osthread(osthread); 732 733 // init thread attributes 734 pthread_attr_t attr; 735 pthread_attr_init(&attr); 736 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 737 738 // Calculate stack size if it's not specified by caller. 739 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size); 740 // In the Linux NPTL pthread implementation the guard size mechanism 741 // is not implemented properly. The posix standard requires adding 742 // the size of the guard pages to the stack size, instead Linux 743 // takes the space out of 'stacksize'. Thus we adapt the requested 744 // stack_size by the size of the guard pages to mimick proper 745 // behaviour. However, be careful not to end up with a size 746 // of zero due to overflow. Don't add the guard page in that case. 747 size_t guard_size = os::Linux::default_guard_size(thr_type); 748 if (stack_size <= SIZE_MAX - guard_size) { 749 stack_size += guard_size; 750 } 751 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned"); 752 753 int status = pthread_attr_setstacksize(&attr, stack_size); 754 assert_status(status == 0, status, "pthread_attr_setstacksize"); 755 756 // Configure glibc guard page. 757 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); 758 759 ThreadState state; 760 761 { 762 pthread_t tid; 763 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread); 764 765 char buf[64]; 766 if (ret == 0) { 767 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ", 768 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 769 } else { 770 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.", 771 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 772 } 773 774 pthread_attr_destroy(&attr); 775 776 if (ret != 0) { 777 // Need to clean up stuff we've allocated so far 778 thread->set_osthread(NULL); 779 delete osthread; 780 return false; 781 } 782 783 // Store pthread info into the OSThread 784 osthread->set_pthread_id(tid); 785 786 // Wait until child thread is either initialized or aborted 787 { 788 Monitor* sync_with_child = osthread->startThread_lock(); 789 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 790 while ((state = osthread->get_state()) == ALLOCATED) { 791 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 792 } 793 } 794 } 795 796 // Aborted due to thread limit being reached 797 if (state == ZOMBIE) { 798 thread->set_osthread(NULL); 799 delete osthread; 800 return false; 801 } 802 803 // The thread is returned suspended (in state INITIALIZED), 804 // and is started higher up in the call chain 805 assert(state == INITIALIZED, "race condition"); 806 return true; 807 } 808 809 ///////////////////////////////////////////////////////////////////////////// 810 // attach existing thread 811 812 // bootstrap the main thread 813 bool os::create_main_thread(JavaThread* thread) { 814 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread"); 815 return create_attached_thread(thread); 816 } 817 818 bool os::create_attached_thread(JavaThread* thread) { 819 #ifdef ASSERT 820 thread->verify_not_published(); 821 #endif 822 823 // Allocate the OSThread object 824 OSThread* osthread = new OSThread(NULL, NULL); 825 826 if (osthread == NULL) { 827 return false; 828 } 829 830 // Store pthread info into the OSThread 831 osthread->set_thread_id(os::Linux::gettid()); 832 osthread->set_pthread_id(::pthread_self()); 833 834 // initialize floating point control register 835 os::Linux::init_thread_fpu_state(); 836 837 // Initial thread state is RUNNABLE 838 osthread->set_state(RUNNABLE); 839 840 thread->set_osthread(osthread); 841 842 if (UseNUMA) { 843 int lgrp_id = os::numa_get_group_id(); 844 if (lgrp_id != -1) { 845 thread->set_lgrp_id(lgrp_id); 846 } 847 } 848 849 if (os::is_primordial_thread()) { 850 // If current thread is primordial thread, its stack is mapped on demand, 851 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map 852 // the entire stack region to avoid SEGV in stack banging. 853 // It is also useful to get around the heap-stack-gap problem on SuSE 854 // kernel (see 4821821 for details). We first expand stack to the top 855 // of yellow zone, then enable stack yellow zone (order is significant, 856 // enabling yellow zone first will crash JVM on SuSE Linux), so there 857 // is no gap between the last two virtual memory regions. 858 859 JavaThread *jt = (JavaThread *)thread; 860 address addr = jt->stack_reserved_zone_base(); 861 assert(addr != NULL, "initialization problem?"); 862 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); 863 864 osthread->set_expanding_stack(); 865 os::Linux::manually_expand_stack(jt, addr); 866 osthread->clear_expanding_stack(); 867 } 868 869 // initialize signal mask for this thread 870 // and save the caller's signal mask 871 os::Linux::hotspot_sigmask(thread); 872 873 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 874 os::current_thread_id(), (uintx) pthread_self()); 875 876 return true; 877 } 878 879 void os::pd_start_thread(Thread* thread) { 880 OSThread * osthread = thread->osthread(); 881 assert(osthread->get_state() != INITIALIZED, "just checking"); 882 Monitor* sync_with_child = osthread->startThread_lock(); 883 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 884 sync_with_child->notify(); 885 } 886 887 // Free Linux resources related to the OSThread 888 void os::free_thread(OSThread* osthread) { 889 assert(osthread != NULL, "osthread not set"); 890 891 // We are told to free resources of the argument thread, 892 // but we can only really operate on the current thread. 893 assert(Thread::current()->osthread() == osthread, 894 "os::free_thread but not current thread"); 895 896 #ifdef ASSERT 897 sigset_t current; 898 sigemptyset(¤t); 899 pthread_sigmask(SIG_SETMASK, NULL, ¤t); 900 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!"); 901 #endif 902 903 // Restore caller's signal mask 904 sigset_t sigmask = osthread->caller_sigmask(); 905 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 906 907 delete osthread; 908 } 909 910 ////////////////////////////////////////////////////////////////////////////// 911 // primordial thread 912 913 // Check if current thread is the primordial thread, similar to Solaris thr_main. 914 bool os::is_primordial_thread(void) { 915 if (suppress_primordial_thread_resolution) { 916 return false; 917 } 918 char dummy; 919 // If called before init complete, thread stack bottom will be null. 920 // Can be called if fatal error occurs before initialization. 921 if (os::Linux::initial_thread_stack_bottom() == NULL) return false; 922 assert(os::Linux::initial_thread_stack_bottom() != NULL && 923 os::Linux::initial_thread_stack_size() != 0, 924 "os::init did not locate primordial thread's stack region"); 925 if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() && 926 (address)&dummy < os::Linux::initial_thread_stack_bottom() + 927 os::Linux::initial_thread_stack_size()) { 928 return true; 929 } else { 930 return false; 931 } 932 } 933 934 // Find the virtual memory area that contains addr 935 static bool find_vma(address addr, address* vma_low, address* vma_high) { 936 FILE *fp = fopen("/proc/self/maps", "r"); 937 if (fp) { 938 address low, high; 939 while (!feof(fp)) { 940 if (fscanf(fp, "%p-%p", &low, &high) == 2) { 941 if (low <= addr && addr < high) { 942 if (vma_low) *vma_low = low; 943 if (vma_high) *vma_high = high; 944 fclose(fp); 945 return true; 946 } 947 } 948 for (;;) { 949 int ch = fgetc(fp); 950 if (ch == EOF || ch == (int)'\n') break; 951 } 952 } 953 fclose(fp); 954 } 955 return false; 956 } 957 958 // Locate primordial thread stack. This special handling of primordial thread stack 959 // is needed because pthread_getattr_np() on most (all?) Linux distros returns 960 // bogus value for the primordial process thread. While the launcher has created 961 // the VM in a new thread since JDK 6, we still have to allow for the use of the 962 // JNI invocation API from a primordial thread. 963 void os::Linux::capture_initial_stack(size_t max_size) { 964 965 // max_size is either 0 (which means accept OS default for thread stacks) or 966 // a user-specified value known to be at least the minimum needed. If we 967 // are actually on the primordial thread we can make it appear that we have a 968 // smaller max_size stack by inserting the guard pages at that location. But we 969 // cannot do anything to emulate a larger stack than what has been provided by 970 // the OS or threading library. In fact if we try to use a stack greater than 971 // what is set by rlimit then we will crash the hosting process. 972 973 // Maximum stack size is the easy part, get it from RLIMIT_STACK. 974 // If this is "unlimited" then it will be a huge value. 975 struct rlimit rlim; 976 getrlimit(RLIMIT_STACK, &rlim); 977 size_t stack_size = rlim.rlim_cur; 978 979 // 6308388: a bug in ld.so will relocate its own .data section to the 980 // lower end of primordial stack; reduce ulimit -s value a little bit 981 // so we won't install guard page on ld.so's data section. 982 // But ensure we don't underflow the stack size - allow 1 page spare 983 if (stack_size >= (size_t)(3 * page_size())) { 984 stack_size -= 2 * page_size(); 985 } 986 987 // Try to figure out where the stack base (top) is. This is harder. 988 // 989 // When an application is started, glibc saves the initial stack pointer in 990 // a global variable "__libc_stack_end", which is then used by system 991 // libraries. __libc_stack_end should be pretty close to stack top. The 992 // variable is available since the very early days. However, because it is 993 // a private interface, it could disappear in the future. 994 // 995 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar 996 // to __libc_stack_end, it is very close to stack top, but isn't the real 997 // stack top. Note that /proc may not exist if VM is running as a chroot 998 // program, so reading /proc/<pid>/stat could fail. Also the contents of 999 // /proc/<pid>/stat could change in the future (though unlikely). 1000 // 1001 // We try __libc_stack_end first. If that doesn't work, look for 1002 // /proc/<pid>/stat. If neither of them works, we use current stack pointer 1003 // as a hint, which should work well in most cases. 1004 1005 uintptr_t stack_start; 1006 1007 // try __libc_stack_end first 1008 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end"); 1009 if (p && *p) { 1010 stack_start = *p; 1011 } else { 1012 // see if we can get the start_stack field from /proc/self/stat 1013 FILE *fp; 1014 int pid; 1015 char state; 1016 int ppid; 1017 int pgrp; 1018 int session; 1019 int nr; 1020 int tpgrp; 1021 unsigned long flags; 1022 unsigned long minflt; 1023 unsigned long cminflt; 1024 unsigned long majflt; 1025 unsigned long cmajflt; 1026 unsigned long utime; 1027 unsigned long stime; 1028 long cutime; 1029 long cstime; 1030 long prio; 1031 long nice; 1032 long junk; 1033 long it_real; 1034 uintptr_t start; 1035 uintptr_t vsize; 1036 intptr_t rss; 1037 uintptr_t rsslim; 1038 uintptr_t scodes; 1039 uintptr_t ecode; 1040 int i; 1041 1042 // Figure what the primordial thread stack base is. Code is inspired 1043 // by email from Hans Boehm. /proc/self/stat begins with current pid, 1044 // followed by command name surrounded by parentheses, state, etc. 1045 char stat[2048]; 1046 int statlen; 1047 1048 fp = fopen("/proc/self/stat", "r"); 1049 if (fp) { 1050 statlen = fread(stat, 1, 2047, fp); 1051 stat[statlen] = '\0'; 1052 fclose(fp); 1053 1054 // Skip pid and the command string. Note that we could be dealing with 1055 // weird command names, e.g. user could decide to rename java launcher 1056 // to "java 1.4.2 :)", then the stat file would look like 1057 // 1234 (java 1.4.2 :)) R ... ... 1058 // We don't really need to know the command string, just find the last 1059 // occurrence of ")" and then start parsing from there. See bug 4726580. 1060 char * s = strrchr(stat, ')'); 1061 1062 i = 0; 1063 if (s) { 1064 // Skip blank chars 1065 do { s++; } while (s && isspace(*s)); 1066 1067 #define _UFM UINTX_FORMAT 1068 #define _DFM INTX_FORMAT 1069 1070 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 1071 // 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 1072 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, 1073 &state, // 3 %c 1074 &ppid, // 4 %d 1075 &pgrp, // 5 %d 1076 &session, // 6 %d 1077 &nr, // 7 %d 1078 &tpgrp, // 8 %d 1079 &flags, // 9 %lu 1080 &minflt, // 10 %lu 1081 &cminflt, // 11 %lu 1082 &majflt, // 12 %lu 1083 &cmajflt, // 13 %lu 1084 &utime, // 14 %lu 1085 &stime, // 15 %lu 1086 &cutime, // 16 %ld 1087 &cstime, // 17 %ld 1088 &prio, // 18 %ld 1089 &nice, // 19 %ld 1090 &junk, // 20 %ld 1091 &it_real, // 21 %ld 1092 &start, // 22 UINTX_FORMAT 1093 &vsize, // 23 UINTX_FORMAT 1094 &rss, // 24 INTX_FORMAT 1095 &rsslim, // 25 UINTX_FORMAT 1096 &scodes, // 26 UINTX_FORMAT 1097 &ecode, // 27 UINTX_FORMAT 1098 &stack_start); // 28 UINTX_FORMAT 1099 } 1100 1101 #undef _UFM 1102 #undef _DFM 1103 1104 if (i != 28 - 2) { 1105 assert(false, "Bad conversion from /proc/self/stat"); 1106 // product mode - assume we are the primordial thread, good luck in the 1107 // embedded case. 1108 warning("Can't detect primordial thread stack location - bad conversion"); 1109 stack_start = (uintptr_t) &rlim; 1110 } 1111 } else { 1112 // For some reason we can't open /proc/self/stat (for example, running on 1113 // FreeBSD with a Linux emulator, or inside chroot), this should work for 1114 // most cases, so don't abort: 1115 warning("Can't detect primordial thread stack location - no /proc/self/stat"); 1116 stack_start = (uintptr_t) &rlim; 1117 } 1118 } 1119 1120 // Now we have a pointer (stack_start) very close to the stack top, the 1121 // next thing to do is to figure out the exact location of stack top. We 1122 // can find out the virtual memory area that contains stack_start by 1123 // reading /proc/self/maps, it should be the last vma in /proc/self/maps, 1124 // and its upper limit is the real stack top. (again, this would fail if 1125 // running inside chroot, because /proc may not exist.) 1126 1127 uintptr_t stack_top; 1128 address low, high; 1129 if (find_vma((address)stack_start, &low, &high)) { 1130 // success, "high" is the true stack top. (ignore "low", because initial 1131 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.) 1132 stack_top = (uintptr_t)high; 1133 } else { 1134 // failed, likely because /proc/self/maps does not exist 1135 warning("Can't detect primordial thread stack location - find_vma failed"); 1136 // best effort: stack_start is normally within a few pages below the real 1137 // stack top, use it as stack top, and reduce stack size so we won't put 1138 // guard page outside stack. 1139 stack_top = stack_start; 1140 stack_size -= 16 * page_size(); 1141 } 1142 1143 // stack_top could be partially down the page so align it 1144 stack_top = align_up(stack_top, page_size()); 1145 1146 // Allowed stack value is minimum of max_size and what we derived from rlimit 1147 if (max_size > 0) { 1148 _initial_thread_stack_size = MIN2(max_size, stack_size); 1149 } else { 1150 // Accept the rlimit max, but if stack is unlimited then it will be huge, so 1151 // clamp it at 8MB as we do on Solaris 1152 _initial_thread_stack_size = MIN2(stack_size, 8*M); 1153 } 1154 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size()); 1155 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; 1156 1157 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!"); 1158 1159 if (log_is_enabled(Info, os, thread)) { 1160 // See if we seem to be on primordial process thread 1161 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) && 1162 uintptr_t(&rlim) < stack_top; 1163 1164 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: " 1165 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT, 1166 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K, 1167 stack_top, intptr_t(_initial_thread_stack_bottom)); 1168 } 1169 } 1170 1171 //////////////////////////////////////////////////////////////////////////////// 1172 // time support 1173 1174 // Time since start-up in seconds to a fine granularity. 1175 // Used by VMSelfDestructTimer and the MemProfiler. 1176 double os::elapsedTime() { 1177 1178 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution 1179 } 1180 1181 jlong os::elapsed_counter() { 1182 return javaTimeNanos() - initial_time_count; 1183 } 1184 1185 jlong os::elapsed_frequency() { 1186 return NANOSECS_PER_SEC; // nanosecond resolution 1187 } 1188 1189 bool os::supports_vtime() { return true; } 1190 bool os::enable_vtime() { return false; } 1191 bool os::vtime_enabled() { return false; } 1192 1193 double os::elapsedVTime() { 1194 struct rusage usage; 1195 int retval = getrusage(RUSAGE_THREAD, &usage); 1196 if (retval == 0) { 1197 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); 1198 } else { 1199 // better than nothing, but not much 1200 return elapsedTime(); 1201 } 1202 } 1203 1204 jlong os::javaTimeMillis() { 1205 timeval time; 1206 int status = gettimeofday(&time, NULL); 1207 assert(status != -1, "linux error"); 1208 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 1209 } 1210 1211 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { 1212 timeval time; 1213 int status = gettimeofday(&time, NULL); 1214 assert(status != -1, "linux error"); 1215 seconds = jlong(time.tv_sec); 1216 nanos = jlong(time.tv_usec) * 1000; 1217 } 1218 1219 1220 #ifndef CLOCK_MONOTONIC 1221 #define CLOCK_MONOTONIC (1) 1222 #endif 1223 1224 void os::Linux::clock_init() { 1225 // we do dlopen's in this particular order due to bug in linux 1226 // dynamical loader (see 6348968) leading to crash on exit 1227 void* handle = dlopen("librt.so.1", RTLD_LAZY); 1228 if (handle == NULL) { 1229 handle = dlopen("librt.so", RTLD_LAZY); 1230 } 1231 1232 if (handle) { 1233 int (*clock_getres_func)(clockid_t, struct timespec*) = 1234 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres"); 1235 int (*clock_gettime_func)(clockid_t, struct timespec*) = 1236 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime"); 1237 if (clock_getres_func && clock_gettime_func) { 1238 // See if monotonic clock is supported by the kernel. Note that some 1239 // early implementations simply return kernel jiffies (updated every 1240 // 1/100 or 1/1000 second). It would be bad to use such a low res clock 1241 // for nano time (though the monotonic property is still nice to have). 1242 // It's fixed in newer kernels, however clock_getres() still returns 1243 // 1/HZ. We check if clock_getres() works, but will ignore its reported 1244 // resolution for now. Hopefully as people move to new kernels, this 1245 // won't be a problem. 1246 struct timespec res; 1247 struct timespec tp; 1248 if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 && 1249 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) { 1250 // yes, monotonic clock is supported 1251 _clock_gettime = clock_gettime_func; 1252 return; 1253 } else { 1254 // close librt if there is no monotonic clock 1255 dlclose(handle); 1256 } 1257 } 1258 } 1259 warning("No monotonic clock was available - timed services may " \ 1260 "be adversely affected if the time-of-day clock changes"); 1261 } 1262 1263 #ifndef SYS_clock_getres 1264 #if defined(X86) || defined(PPC64) || defined(S390) 1265 #define SYS_clock_getres AMD64_ONLY(229) IA32_ONLY(266) PPC64_ONLY(247) S390_ONLY(261) 1266 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1267 #else 1268 #warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time" 1269 #define sys_clock_getres(x,y) -1 1270 #endif 1271 #else 1272 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1273 #endif 1274 1275 void os::Linux::fast_thread_clock_init() { 1276 if (!UseLinuxPosixThreadCPUClocks) { 1277 return; 1278 } 1279 clockid_t clockid; 1280 struct timespec tp; 1281 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) = 1282 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid"); 1283 1284 // Switch to using fast clocks for thread cpu time if 1285 // the sys_clock_getres() returns 0 error code. 1286 // Note, that some kernels may support the current thread 1287 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks 1288 // returned by the pthread_getcpuclockid(). 1289 // If the fast Posix clocks are supported then the sys_clock_getres() 1290 // must return at least tp.tv_sec == 0 which means a resolution 1291 // better than 1 sec. This is extra check for reliability. 1292 1293 if (pthread_getcpuclockid_func && 1294 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 && 1295 sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) { 1296 _supports_fast_thread_cpu_time = true; 1297 _pthread_getcpuclockid = pthread_getcpuclockid_func; 1298 } 1299 } 1300 1301 jlong os::javaTimeNanos() { 1302 if (os::supports_monotonic_clock()) { 1303 struct timespec tp; 1304 int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp); 1305 assert(status == 0, "gettime error"); 1306 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1307 return result; 1308 } else { 1309 timeval time; 1310 int status = gettimeofday(&time, NULL); 1311 assert(status != -1, "linux error"); 1312 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1313 return 1000 * usecs; 1314 } 1315 } 1316 1317 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1318 if (os::supports_monotonic_clock()) { 1319 info_ptr->max_value = ALL_64_BITS; 1320 1321 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1322 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1323 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1324 } else { 1325 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1326 info_ptr->max_value = ALL_64_BITS; 1327 1328 // gettimeofday is a real time clock so it skips 1329 info_ptr->may_skip_backward = true; 1330 info_ptr->may_skip_forward = true; 1331 } 1332 1333 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1334 } 1335 1336 // Return the real, user, and system times in seconds from an 1337 // arbitrary fixed point in the past. 1338 bool os::getTimesSecs(double* process_real_time, 1339 double* process_user_time, 1340 double* process_system_time) { 1341 struct tms ticks; 1342 clock_t real_ticks = times(&ticks); 1343 1344 if (real_ticks == (clock_t) (-1)) { 1345 return false; 1346 } else { 1347 double ticks_per_second = (double) clock_tics_per_sec; 1348 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1349 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1350 *process_real_time = ((double) real_ticks) / ticks_per_second; 1351 1352 return true; 1353 } 1354 } 1355 1356 1357 char * os::local_time_string(char *buf, size_t buflen) { 1358 struct tm t; 1359 time_t long_time; 1360 time(&long_time); 1361 localtime_r(&long_time, &t); 1362 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1363 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1364 t.tm_hour, t.tm_min, t.tm_sec); 1365 return buf; 1366 } 1367 1368 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1369 return localtime_r(clock, res); 1370 } 1371 1372 //////////////////////////////////////////////////////////////////////////////// 1373 // runtime exit support 1374 1375 // Note: os::shutdown() might be called very early during initialization, or 1376 // called from signal handler. Before adding something to os::shutdown(), make 1377 // sure it is async-safe and can handle partially initialized VM. 1378 void os::shutdown() { 1379 1380 // allow PerfMemory to attempt cleanup of any persistent resources 1381 perfMemory_exit(); 1382 1383 // needs to remove object in file system 1384 AttachListener::abort(); 1385 1386 // flush buffered output, finish log files 1387 ostream_abort(); 1388 1389 // Check for abort hook 1390 abort_hook_t abort_hook = Arguments::abort_hook(); 1391 if (abort_hook != NULL) { 1392 abort_hook(); 1393 } 1394 1395 } 1396 1397 // Note: os::abort() might be called very early during initialization, or 1398 // called from signal handler. Before adding something to os::abort(), make 1399 // sure it is async-safe and can handle partially initialized VM. 1400 void os::abort(bool dump_core, void* siginfo, const void* context) { 1401 os::shutdown(); 1402 if (dump_core) { 1403 #ifndef PRODUCT 1404 fdStream out(defaultStream::output_fd()); 1405 out.print_raw("Current thread is "); 1406 char buf[16]; 1407 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1408 out.print_raw_cr(buf); 1409 out.print_raw_cr("Dumping core ..."); 1410 #endif 1411 ::abort(); // dump core 1412 } 1413 1414 ::exit(1); 1415 } 1416 1417 // Die immediately, no exit hook, no abort hook, no cleanup. 1418 void os::die() { 1419 ::abort(); 1420 } 1421 1422 1423 // This method is a copy of JDK's sysGetLastErrorString 1424 // from src/solaris/hpi/src/system_md.c 1425 1426 size_t os::lasterror(char *buf, size_t len) { 1427 if (errno == 0) return 0; 1428 1429 const char *s = os::strerror(errno); 1430 size_t n = ::strlen(s); 1431 if (n >= len) { 1432 n = len - 1; 1433 } 1434 ::strncpy(buf, s, n); 1435 buf[n] = '\0'; 1436 return n; 1437 } 1438 1439 // thread_id is kernel thread id (similar to Solaris LWP id) 1440 intx os::current_thread_id() { return os::Linux::gettid(); } 1441 int os::current_process_id() { 1442 return ::getpid(); 1443 } 1444 1445 // DLL functions 1446 1447 const char* os::dll_file_extension() { return ".so"; } 1448 1449 // This must be hard coded because it's the system's temporary 1450 // directory not the java application's temp directory, ala java.io.tmpdir. 1451 const char* os::get_temp_directory() { return "/tmp"; } 1452 1453 static bool file_exists(const char* filename) { 1454 struct stat statbuf; 1455 if (filename == NULL || strlen(filename) == 0) { 1456 return false; 1457 } 1458 return os::stat(filename, &statbuf) == 0; 1459 } 1460 1461 // check if addr is inside libjvm.so 1462 bool os::address_is_in_vm(address addr) { 1463 static address libjvm_base_addr; 1464 Dl_info dlinfo; 1465 1466 if (libjvm_base_addr == NULL) { 1467 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1468 libjvm_base_addr = (address)dlinfo.dli_fbase; 1469 } 1470 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1471 } 1472 1473 if (dladdr((void *)addr, &dlinfo) != 0) { 1474 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1475 } 1476 1477 return false; 1478 } 1479 1480 bool os::dll_address_to_function_name(address addr, char *buf, 1481 int buflen, int *offset, 1482 bool demangle) { 1483 // buf is not optional, but offset is optional 1484 assert(buf != NULL, "sanity check"); 1485 1486 Dl_info dlinfo; 1487 1488 if (dladdr((void*)addr, &dlinfo) != 0) { 1489 // see if we have a matching symbol 1490 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1491 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) { 1492 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1493 } 1494 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1495 return true; 1496 } 1497 // no matching symbol so try for just file info 1498 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1499 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1500 buf, buflen, offset, dlinfo.dli_fname, demangle)) { 1501 return true; 1502 } 1503 } 1504 } 1505 1506 buf[0] = '\0'; 1507 if (offset != NULL) *offset = -1; 1508 return false; 1509 } 1510 1511 struct _address_to_library_name { 1512 address addr; // input : memory address 1513 size_t buflen; // size of fname 1514 char* fname; // output: library name 1515 address base; // library base addr 1516 }; 1517 1518 static int address_to_library_name_callback(struct dl_phdr_info *info, 1519 size_t size, void *data) { 1520 int i; 1521 bool found = false; 1522 address libbase = NULL; 1523 struct _address_to_library_name * d = (struct _address_to_library_name *)data; 1524 1525 // iterate through all loadable segments 1526 for (i = 0; i < info->dlpi_phnum; i++) { 1527 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); 1528 if (info->dlpi_phdr[i].p_type == PT_LOAD) { 1529 // base address of a library is the lowest address of its loaded 1530 // segments. 1531 if (libbase == NULL || libbase > segbase) { 1532 libbase = segbase; 1533 } 1534 // see if 'addr' is within current segment 1535 if (segbase <= d->addr && 1536 d->addr < segbase + info->dlpi_phdr[i].p_memsz) { 1537 found = true; 1538 } 1539 } 1540 } 1541 1542 // dlpi_name is NULL or empty if the ELF file is executable, return 0 1543 // so dll_address_to_library_name() can fall through to use dladdr() which 1544 // can figure out executable name from argv[0]. 1545 if (found && info->dlpi_name && info->dlpi_name[0]) { 1546 d->base = libbase; 1547 if (d->fname) { 1548 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); 1549 } 1550 return 1; 1551 } 1552 return 0; 1553 } 1554 1555 bool os::dll_address_to_library_name(address addr, char* buf, 1556 int buflen, int* offset) { 1557 // buf is not optional, but offset is optional 1558 assert(buf != NULL, "sanity check"); 1559 1560 Dl_info dlinfo; 1561 struct _address_to_library_name data; 1562 1563 // There is a bug in old glibc dladdr() implementation that it could resolve 1564 // to wrong library name if the .so file has a base address != NULL. Here 1565 // we iterate through the program headers of all loaded libraries to find 1566 // out which library 'addr' really belongs to. This workaround can be 1567 // removed once the minimum requirement for glibc is moved to 2.3.x. 1568 data.addr = addr; 1569 data.fname = buf; 1570 data.buflen = buflen; 1571 data.base = NULL; 1572 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); 1573 1574 if (rslt) { 1575 // buf already contains library name 1576 if (offset) *offset = addr - data.base; 1577 return true; 1578 } 1579 if (dladdr((void*)addr, &dlinfo) != 0) { 1580 if (dlinfo.dli_fname != NULL) { 1581 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1582 } 1583 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1584 *offset = addr - (address)dlinfo.dli_fbase; 1585 } 1586 return true; 1587 } 1588 1589 buf[0] = '\0'; 1590 if (offset) *offset = -1; 1591 return false; 1592 } 1593 1594 // Loads .dll/.so and 1595 // in case of error it checks if .dll/.so was built for the 1596 // same architecture as Hotspot is running on 1597 1598 1599 // Remember the stack's state. The Linux dynamic linker will change 1600 // the stack to 'executable' at most once, so we must safepoint only once. 1601 bool os::Linux::_stack_is_executable = false; 1602 1603 // VM operation that loads a library. This is necessary if stack protection 1604 // of the Java stacks can be lost during loading the library. If we 1605 // do not stop the Java threads, they can stack overflow before the stacks 1606 // are protected again. 1607 class VM_LinuxDllLoad: public VM_Operation { 1608 private: 1609 const char *_filename; 1610 char *_ebuf; 1611 int _ebuflen; 1612 void *_lib; 1613 public: 1614 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) : 1615 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {} 1616 VMOp_Type type() const { return VMOp_LinuxDllLoad; } 1617 void doit() { 1618 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen); 1619 os::Linux::_stack_is_executable = true; 1620 } 1621 void* loaded_library() { return _lib; } 1622 }; 1623 1624 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1625 void * result = NULL; 1626 bool load_attempted = false; 1627 1628 // Check whether the library to load might change execution rights 1629 // of the stack. If they are changed, the protection of the stack 1630 // guard pages will be lost. We need a safepoint to fix this. 1631 // 1632 // See Linux man page execstack(8) for more info. 1633 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) { 1634 if (!ElfFile::specifies_noexecstack(filename)) { 1635 if (!is_init_completed()) { 1636 os::Linux::_stack_is_executable = true; 1637 // This is OK - No Java threads have been created yet, and hence no 1638 // stack guard pages to fix. 1639 // 1640 // This should happen only when you are building JDK7 using a very 1641 // old version of JDK6 (e.g., with JPRT) and running test_gamma. 1642 // 1643 // Dynamic loader will make all stacks executable after 1644 // this function returns, and will not do that again. 1645 assert(Threads::number_of_threads() == 0, "no Java threads should exist yet."); 1646 } else { 1647 warning("You have loaded library %s which might have disabled stack guard. " 1648 "The VM will try to fix the stack guard now.\n" 1649 "It's highly recommended that you fix the library with " 1650 "'execstack -c <libfile>', or link it with '-z noexecstack'.", 1651 filename); 1652 1653 assert(Thread::current()->is_Java_thread(), "must be Java thread"); 1654 JavaThread *jt = JavaThread::current(); 1655 if (jt->thread_state() != _thread_in_native) { 1656 // This happens when a compiler thread tries to load a hsdis-<arch>.so file 1657 // that requires ExecStack. Cannot enter safe point. Let's give up. 1658 warning("Unable to fix stack guard. Giving up."); 1659 } else { 1660 if (!LoadExecStackDllInVMThread) { 1661 // This is for the case where the DLL has an static 1662 // constructor function that executes JNI code. We cannot 1663 // load such DLLs in the VMThread. 1664 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1665 } 1666 1667 ThreadInVMfromNative tiv(jt); 1668 debug_only(VMNativeEntryWrapper vew;) 1669 1670 VM_LinuxDllLoad op(filename, ebuf, ebuflen); 1671 VMThread::execute(&op); 1672 if (LoadExecStackDllInVMThread) { 1673 result = op.loaded_library(); 1674 } 1675 load_attempted = true; 1676 } 1677 } 1678 } 1679 } 1680 1681 if (!load_attempted) { 1682 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1683 } 1684 1685 if (result != NULL) { 1686 // Successful loading 1687 return result; 1688 } 1689 1690 Elf32_Ehdr elf_head; 1691 int diag_msg_max_length=ebuflen-strlen(ebuf); 1692 char* diag_msg_buf=ebuf+strlen(ebuf); 1693 1694 if (diag_msg_max_length==0) { 1695 // No more space in ebuf for additional diagnostics message 1696 return NULL; 1697 } 1698 1699 1700 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1701 1702 if (file_descriptor < 0) { 1703 // Can't open library, report dlerror() message 1704 return NULL; 1705 } 1706 1707 bool failed_to_read_elf_head= 1708 (sizeof(elf_head)!= 1709 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1710 1711 ::close(file_descriptor); 1712 if (failed_to_read_elf_head) { 1713 // file i/o error - report dlerror() msg 1714 return NULL; 1715 } 1716 1717 typedef struct { 1718 Elf32_Half code; // Actual value as defined in elf.h 1719 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1720 unsigned char elf_class; // 32 or 64 bit 1721 unsigned char endianess; // MSB or LSB 1722 char* name; // String representation 1723 } arch_t; 1724 1725 #ifndef EM_486 1726 #define EM_486 6 /* Intel 80486 */ 1727 #endif 1728 #ifndef EM_AARCH64 1729 #define EM_AARCH64 183 /* ARM AARCH64 */ 1730 #endif 1731 1732 static const arch_t arch_array[]={ 1733 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1734 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1735 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1736 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1737 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1738 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1739 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1740 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1741 #if defined(VM_LITTLE_ENDIAN) 1742 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"}, 1743 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"}, 1744 #else 1745 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1746 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"}, 1747 #endif 1748 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1749 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1750 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1751 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1752 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1753 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1754 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}, 1755 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"}, 1756 }; 1757 1758 #if (defined IA32) 1759 static Elf32_Half running_arch_code=EM_386; 1760 #elif (defined AMD64) 1761 static Elf32_Half running_arch_code=EM_X86_64; 1762 #elif (defined IA64) 1763 static Elf32_Half running_arch_code=EM_IA_64; 1764 #elif (defined __sparc) && (defined _LP64) 1765 static Elf32_Half running_arch_code=EM_SPARCV9; 1766 #elif (defined __sparc) && (!defined _LP64) 1767 static Elf32_Half running_arch_code=EM_SPARC; 1768 #elif (defined __powerpc64__) 1769 static Elf32_Half running_arch_code=EM_PPC64; 1770 #elif (defined __powerpc__) 1771 static Elf32_Half running_arch_code=EM_PPC; 1772 #elif (defined AARCH64) 1773 static Elf32_Half running_arch_code=EM_AARCH64; 1774 #elif (defined ARM) 1775 static Elf32_Half running_arch_code=EM_ARM; 1776 #elif (defined S390) 1777 static Elf32_Half running_arch_code=EM_S390; 1778 #elif (defined ALPHA) 1779 static Elf32_Half running_arch_code=EM_ALPHA; 1780 #elif (defined MIPSEL) 1781 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1782 #elif (defined PARISC) 1783 static Elf32_Half running_arch_code=EM_PARISC; 1784 #elif (defined MIPS) 1785 static Elf32_Half running_arch_code=EM_MIPS; 1786 #elif (defined M68K) 1787 static Elf32_Half running_arch_code=EM_68K; 1788 #elif (defined SH) 1789 static Elf32_Half running_arch_code=EM_SH; 1790 #else 1791 #error Method os::dll_load requires that one of following is defined:\ 1792 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc 1793 #endif 1794 1795 // Identify compatability class for VM's architecture and library's architecture 1796 // Obtain string descriptions for architectures 1797 1798 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1799 int running_arch_index=-1; 1800 1801 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1802 if (running_arch_code == arch_array[i].code) { 1803 running_arch_index = i; 1804 } 1805 if (lib_arch.code == arch_array[i].code) { 1806 lib_arch.compat_class = arch_array[i].compat_class; 1807 lib_arch.name = arch_array[i].name; 1808 } 1809 } 1810 1811 assert(running_arch_index != -1, 1812 "Didn't find running architecture code (running_arch_code) in arch_array"); 1813 if (running_arch_index == -1) { 1814 // Even though running architecture detection failed 1815 // we may still continue with reporting dlerror() message 1816 return NULL; 1817 } 1818 1819 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1820 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1821 return NULL; 1822 } 1823 1824 #ifndef S390 1825 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1826 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1827 return NULL; 1828 } 1829 #endif // !S390 1830 1831 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1832 if (lib_arch.name!=NULL) { 1833 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1834 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1835 lib_arch.name, arch_array[running_arch_index].name); 1836 } else { 1837 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1838 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1839 lib_arch.code, 1840 arch_array[running_arch_index].name); 1841 } 1842 } 1843 1844 return NULL; 1845 } 1846 1847 void * os::Linux::dlopen_helper(const char *filename, char *ebuf, 1848 int ebuflen) { 1849 void * result = ::dlopen(filename, RTLD_LAZY); 1850 if (result == NULL) { 1851 ::strncpy(ebuf, ::dlerror(), ebuflen - 1); 1852 ebuf[ebuflen-1] = '\0'; 1853 } 1854 return result; 1855 } 1856 1857 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf, 1858 int ebuflen) { 1859 void * result = NULL; 1860 if (LoadExecStackDllInVMThread) { 1861 result = dlopen_helper(filename, ebuf, ebuflen); 1862 } 1863 1864 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a 1865 // library that requires an executable stack, or which does not have this 1866 // stack attribute set, dlopen changes the stack attribute to executable. The 1867 // read protection of the guard pages gets lost. 1868 // 1869 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad 1870 // may have been queued at the same time. 1871 1872 if (!_stack_is_executable) { 1873 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) { 1874 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized 1875 jt->stack_guards_enabled()) { // No pending stack overflow exceptions 1876 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) { 1877 warning("Attempt to reguard stack yellow zone failed."); 1878 } 1879 } 1880 } 1881 } 1882 1883 return result; 1884 } 1885 1886 void* os::dll_lookup(void* handle, const char* name) { 1887 void* res = dlsym(handle, name); 1888 return res; 1889 } 1890 1891 void* os::get_default_process_handle() { 1892 return (void*)::dlopen(NULL, RTLD_LAZY); 1893 } 1894 1895 static bool _print_ascii_file(const char* filename, outputStream* st) { 1896 int fd = ::open(filename, O_RDONLY); 1897 if (fd == -1) { 1898 return false; 1899 } 1900 1901 char buf[33]; 1902 int bytes; 1903 buf[32] = '\0'; 1904 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) { 1905 st->print_raw(buf, bytes); 1906 } 1907 1908 ::close(fd); 1909 1910 return true; 1911 } 1912 1913 void os::print_dll_info(outputStream *st) { 1914 st->print_cr("Dynamic libraries:"); 1915 1916 char fname[32]; 1917 pid_t pid = os::Linux::gettid(); 1918 1919 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); 1920 1921 if (!_print_ascii_file(fname, st)) { 1922 st->print("Can not get library information for pid = %d\n", pid); 1923 } 1924 } 1925 1926 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1927 FILE *procmapsFile = NULL; 1928 1929 // Open the procfs maps file for the current process 1930 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) { 1931 // Allocate PATH_MAX for file name plus a reasonable size for other fields. 1932 char line[PATH_MAX + 100]; 1933 1934 // Read line by line from 'file' 1935 while (fgets(line, sizeof(line), procmapsFile) != NULL) { 1936 u8 base, top, offset, inode; 1937 char permissions[5]; 1938 char device[6]; 1939 char name[PATH_MAX + 1]; 1940 1941 // Parse fields from line 1942 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s", 1943 &base, &top, permissions, &offset, device, &inode, name); 1944 1945 // Filter by device id '00:00' so that we only get file system mapped files. 1946 if (strcmp(device, "00:00") != 0) { 1947 1948 // Call callback with the fields of interest 1949 if(callback(name, (address)base, (address)top, param)) { 1950 // Oops abort, callback aborted 1951 fclose(procmapsFile); 1952 return 1; 1953 } 1954 } 1955 } 1956 fclose(procmapsFile); 1957 } 1958 return 0; 1959 } 1960 1961 void os::print_os_info_brief(outputStream* st) { 1962 os::Linux::print_distro_info(st); 1963 1964 os::Posix::print_uname_info(st); 1965 1966 os::Linux::print_libversion_info(st); 1967 1968 } 1969 1970 void os::print_os_info(outputStream* st) { 1971 st->print("OS:"); 1972 1973 os::Linux::print_distro_info(st); 1974 1975 os::Posix::print_uname_info(st); 1976 1977 // Print warning if unsafe chroot environment detected 1978 if (unsafe_chroot_detected) { 1979 st->print("WARNING!! "); 1980 st->print_cr("%s", unstable_chroot_error); 1981 } 1982 1983 os::Linux::print_libversion_info(st); 1984 1985 os::Posix::print_rlimit_info(st); 1986 1987 os::Posix::print_load_average(st); 1988 1989 os::Linux::print_full_memory_info(st); 1990 1991 os::Linux::print_proc_sys_info(st); 1992 1993 os::Linux::print_container_info(st); 1994 } 1995 1996 // Try to identify popular distros. 1997 // Most Linux distributions have a /etc/XXX-release file, which contains 1998 // the OS version string. Newer Linux distributions have a /etc/lsb-release 1999 // file that also contains the OS version string. Some have more than one 2000 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and 2001 // /etc/redhat-release.), so the order is important. 2002 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have 2003 // their own specific XXX-release file as well as a redhat-release file. 2004 // Because of this the XXX-release file needs to be searched for before the 2005 // redhat-release file. 2006 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the 2007 // search for redhat-release / SuSE-release needs to be before lsb-release. 2008 // Since the lsb-release file is the new standard it needs to be searched 2009 // before the older style release files. 2010 // Searching system-release (Red Hat) and os-release (other Linuxes) are a 2011 // next to last resort. The os-release file is a new standard that contains 2012 // distribution information and the system-release file seems to be an old 2013 // standard that has been replaced by the lsb-release and os-release files. 2014 // Searching for the debian_version file is the last resort. It contains 2015 // an informative string like "6.0.6" or "wheezy/sid". Because of this 2016 // "Debian " is printed before the contents of the debian_version file. 2017 2018 const char* distro_files[] = { 2019 "/etc/oracle-release", 2020 "/etc/mandriva-release", 2021 "/etc/mandrake-release", 2022 "/etc/sun-release", 2023 "/etc/redhat-release", 2024 "/etc/SuSE-release", 2025 "/etc/lsb-release", 2026 "/etc/turbolinux-release", 2027 "/etc/gentoo-release", 2028 "/etc/ltib-release", 2029 "/etc/angstrom-version", 2030 "/etc/system-release", 2031 "/etc/os-release", 2032 NULL }; 2033 2034 void os::Linux::print_distro_info(outputStream* st) { 2035 for (int i = 0;; i++) { 2036 const char* file = distro_files[i]; 2037 if (file == NULL) { 2038 break; // done 2039 } 2040 // If file prints, we found it. 2041 if (_print_ascii_file(file, st)) { 2042 return; 2043 } 2044 } 2045 2046 if (file_exists("/etc/debian_version")) { 2047 st->print("Debian "); 2048 _print_ascii_file("/etc/debian_version", st); 2049 } else { 2050 st->print("Linux"); 2051 } 2052 st->cr(); 2053 } 2054 2055 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) { 2056 char buf[256]; 2057 while (fgets(buf, sizeof(buf), fp)) { 2058 // Edit out extra stuff in expected format 2059 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) { 2060 char* ptr = strstr(buf, "\""); // the name is in quotes 2061 if (ptr != NULL) { 2062 ptr++; // go beyond first quote 2063 char* nl = strchr(ptr, '\"'); 2064 if (nl != NULL) *nl = '\0'; 2065 strncpy(distro, ptr, length); 2066 } else { 2067 ptr = strstr(buf, "="); 2068 ptr++; // go beyond equals then 2069 char* nl = strchr(ptr, '\n'); 2070 if (nl != NULL) *nl = '\0'; 2071 strncpy(distro, ptr, length); 2072 } 2073 return; 2074 } else if (get_first_line) { 2075 char* nl = strchr(buf, '\n'); 2076 if (nl != NULL) *nl = '\0'; 2077 strncpy(distro, buf, length); 2078 return; 2079 } 2080 } 2081 // print last line and close 2082 char* nl = strchr(buf, '\n'); 2083 if (nl != NULL) *nl = '\0'; 2084 strncpy(distro, buf, length); 2085 } 2086 2087 static void parse_os_info(char* distro, size_t length, const char* file) { 2088 FILE* fp = fopen(file, "r"); 2089 if (fp != NULL) { 2090 // if suse format, print out first line 2091 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0); 2092 parse_os_info_helper(fp, distro, length, get_first_line); 2093 fclose(fp); 2094 } 2095 } 2096 2097 void os::get_summary_os_info(char* buf, size_t buflen) { 2098 for (int i = 0;; i++) { 2099 const char* file = distro_files[i]; 2100 if (file == NULL) { 2101 break; // ran out of distro_files 2102 } 2103 if (file_exists(file)) { 2104 parse_os_info(buf, buflen, file); 2105 return; 2106 } 2107 } 2108 // special case for debian 2109 if (file_exists("/etc/debian_version")) { 2110 strncpy(buf, "Debian ", buflen); 2111 parse_os_info(&buf[7], buflen-7, "/etc/debian_version"); 2112 } else { 2113 strncpy(buf, "Linux", buflen); 2114 } 2115 } 2116 2117 void os::Linux::print_libversion_info(outputStream* st) { 2118 // libc, pthread 2119 st->print("libc:"); 2120 st->print("%s ", os::Linux::glibc_version()); 2121 st->print("%s ", os::Linux::libpthread_version()); 2122 st->cr(); 2123 } 2124 2125 void os::Linux::print_proc_sys_info(outputStream* st) { 2126 st->cr(); 2127 st->print_cr("/proc/sys/kernel/threads-max (system-wide limit on the number of threads):"); 2128 _print_ascii_file("/proc/sys/kernel/threads-max", st); 2129 st->cr(); 2130 st->cr(); 2131 2132 st->print_cr("/proc/sys/vm/max_map_count (maximum number of memory map areas a process may have):"); 2133 _print_ascii_file("/proc/sys/vm/max_map_count", st); 2134 st->cr(); 2135 st->cr(); 2136 2137 st->print_cr("/proc/sys/kernel/pid_max (system-wide limit on number of process identifiers):"); 2138 _print_ascii_file("/proc/sys/kernel/pid_max", st); 2139 st->cr(); 2140 st->cr(); 2141 } 2142 2143 void os::Linux::print_full_memory_info(outputStream* st) { 2144 st->print("\n/proc/meminfo:\n"); 2145 _print_ascii_file("/proc/meminfo", st); 2146 st->cr(); 2147 } 2148 2149 void os::Linux::print_container_info(outputStream* st) { 2150 if (!OSContainer::is_containerized()) { 2151 return; 2152 } 2153 2154 st->print("container (cgroup) information:\n"); 2155 2156 const char *p_ct = OSContainer::container_type(); 2157 st->print("container_type: %s\n", p_ct != NULL ? p_ct : "failed"); 2158 2159 char *p = OSContainer::cpu_cpuset_cpus(); 2160 st->print("cpu_cpuset_cpus: %s\n", p != NULL ? p : "failed"); 2161 free(p); 2162 2163 p = OSContainer::cpu_cpuset_memory_nodes(); 2164 st->print("cpu_memory_nodes: %s\n", p != NULL ? p : "failed"); 2165 free(p); 2166 2167 int i = OSContainer::active_processor_count(); 2168 if (i > 0) { 2169 st->print("active_processor_count: %d\n", i); 2170 } else { 2171 st->print("active_processor_count: failed\n"); 2172 } 2173 2174 i = OSContainer::cpu_quota(); 2175 st->print("cpu_quota: %d\n", i); 2176 2177 i = OSContainer::cpu_period(); 2178 st->print("cpu_period: %d\n", i); 2179 2180 i = OSContainer::cpu_shares(); 2181 st->print("cpu_shares: %d\n", i); 2182 2183 jlong j = OSContainer::memory_limit_in_bytes(); 2184 st->print("memory_limit_in_bytes: " JLONG_FORMAT "\n", j); 2185 2186 j = OSContainer::memory_and_swap_limit_in_bytes(); 2187 st->print("memory_and_swap_limit_in_bytes: " JLONG_FORMAT "\n", j); 2188 2189 j = OSContainer::memory_soft_limit_in_bytes(); 2190 st->print("memory_soft_limit_in_bytes: " JLONG_FORMAT "\n", j); 2191 2192 j = OSContainer::OSContainer::memory_usage_in_bytes(); 2193 st->print("memory_usage_in_bytes: " JLONG_FORMAT "\n", j); 2194 2195 j = OSContainer::OSContainer::memory_max_usage_in_bytes(); 2196 st->print("memory_max_usage_in_bytes: " JLONG_FORMAT "\n", j); 2197 st->cr(); 2198 } 2199 2200 void os::print_memory_info(outputStream* st) { 2201 2202 st->print("Memory:"); 2203 st->print(" %dk page", os::vm_page_size()>>10); 2204 2205 // values in struct sysinfo are "unsigned long" 2206 struct sysinfo si; 2207 sysinfo(&si); 2208 2209 st->print(", physical " UINT64_FORMAT "k", 2210 os::physical_memory() >> 10); 2211 st->print("(" UINT64_FORMAT "k free)", 2212 os::available_memory() >> 10); 2213 st->print(", swap " UINT64_FORMAT "k", 2214 ((jlong)si.totalswap * si.mem_unit) >> 10); 2215 st->print("(" UINT64_FORMAT "k free)", 2216 ((jlong)si.freeswap * si.mem_unit) >> 10); 2217 st->cr(); 2218 } 2219 2220 // Print the first "model name" line and the first "flags" line 2221 // that we find and nothing more. We assume "model name" comes 2222 // before "flags" so if we find a second "model name", then the 2223 // "flags" field is considered missing. 2224 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) { 2225 #if defined(IA32) || defined(AMD64) 2226 // Other platforms have less repetitive cpuinfo files 2227 FILE *fp = fopen("/proc/cpuinfo", "r"); 2228 if (fp) { 2229 while (!feof(fp)) { 2230 if (fgets(buf, buflen, fp)) { 2231 // Assume model name comes before flags 2232 bool model_name_printed = false; 2233 if (strstr(buf, "model name") != NULL) { 2234 if (!model_name_printed) { 2235 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n"); 2236 st->print_raw(buf); 2237 model_name_printed = true; 2238 } else { 2239 // model name printed but not flags? Odd, just return 2240 fclose(fp); 2241 return true; 2242 } 2243 } 2244 // print the flags line too 2245 if (strstr(buf, "flags") != NULL) { 2246 st->print_raw(buf); 2247 fclose(fp); 2248 return true; 2249 } 2250 } 2251 } 2252 fclose(fp); 2253 } 2254 #endif // x86 platforms 2255 return false; 2256 } 2257 2258 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) { 2259 // Only print the model name if the platform provides this as a summary 2260 if (!print_model_name_and_flags(st, buf, buflen)) { 2261 st->print("\n/proc/cpuinfo:\n"); 2262 if (!_print_ascii_file("/proc/cpuinfo", st)) { 2263 st->print_cr(" <Not Available>"); 2264 } 2265 } 2266 } 2267 2268 #if defined(AMD64) || defined(IA32) || defined(X32) 2269 const char* search_string = "model name"; 2270 #elif defined(M68K) 2271 const char* search_string = "CPU"; 2272 #elif defined(PPC64) 2273 const char* search_string = "cpu"; 2274 #elif defined(S390) 2275 const char* search_string = "processor"; 2276 #elif defined(SPARC) 2277 const char* search_string = "cpu"; 2278 #else 2279 const char* search_string = "Processor"; 2280 #endif 2281 2282 // Parses the cpuinfo file for string representing the model name. 2283 void os::get_summary_cpu_info(char* cpuinfo, size_t length) { 2284 FILE* fp = fopen("/proc/cpuinfo", "r"); 2285 if (fp != NULL) { 2286 while (!feof(fp)) { 2287 char buf[256]; 2288 if (fgets(buf, sizeof(buf), fp)) { 2289 char* start = strstr(buf, search_string); 2290 if (start != NULL) { 2291 char *ptr = start + strlen(search_string); 2292 char *end = buf + strlen(buf); 2293 while (ptr != end) { 2294 // skip whitespace and colon for the rest of the name. 2295 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') { 2296 break; 2297 } 2298 ptr++; 2299 } 2300 if (ptr != end) { 2301 // reasonable string, get rid of newline and keep the rest 2302 char* nl = strchr(buf, '\n'); 2303 if (nl != NULL) *nl = '\0'; 2304 strncpy(cpuinfo, ptr, length); 2305 fclose(fp); 2306 return; 2307 } 2308 } 2309 } 2310 } 2311 fclose(fp); 2312 } 2313 // cpuinfo not found or parsing failed, just print generic string. The entire 2314 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86) 2315 #if defined(AARCH64) 2316 strncpy(cpuinfo, "AArch64", length); 2317 #elif defined(AMD64) 2318 strncpy(cpuinfo, "x86_64", length); 2319 #elif defined(ARM) // Order wrt. AARCH64 is relevant! 2320 strncpy(cpuinfo, "ARM", length); 2321 #elif defined(IA32) 2322 strncpy(cpuinfo, "x86_32", length); 2323 #elif defined(IA64) 2324 strncpy(cpuinfo, "IA64", length); 2325 #elif defined(PPC) 2326 strncpy(cpuinfo, "PPC64", length); 2327 #elif defined(S390) 2328 strncpy(cpuinfo, "S390", length); 2329 #elif defined(SPARC) 2330 strncpy(cpuinfo, "sparcv9", length); 2331 #elif defined(ZERO_LIBARCH) 2332 strncpy(cpuinfo, ZERO_LIBARCH, length); 2333 #else 2334 strncpy(cpuinfo, "unknown", length); 2335 #endif 2336 } 2337 2338 static void print_signal_handler(outputStream* st, int sig, 2339 char* buf, size_t buflen); 2340 2341 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 2342 st->print_cr("Signal Handlers:"); 2343 print_signal_handler(st, SIGSEGV, buf, buflen); 2344 print_signal_handler(st, SIGBUS , buf, buflen); 2345 print_signal_handler(st, SIGFPE , buf, buflen); 2346 print_signal_handler(st, SIGPIPE, buf, buflen); 2347 print_signal_handler(st, SIGXFSZ, buf, buflen); 2348 print_signal_handler(st, SIGILL , buf, buflen); 2349 print_signal_handler(st, SR_signum, buf, buflen); 2350 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 2351 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 2352 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 2353 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 2354 #if defined(PPC64) 2355 print_signal_handler(st, SIGTRAP, buf, buflen); 2356 #endif 2357 } 2358 2359 static char saved_jvm_path[MAXPATHLEN] = {0}; 2360 2361 // Find the full path to the current module, libjvm.so 2362 void os::jvm_path(char *buf, jint buflen) { 2363 // Error checking. 2364 if (buflen < MAXPATHLEN) { 2365 assert(false, "must use a large-enough buffer"); 2366 buf[0] = '\0'; 2367 return; 2368 } 2369 // Lazy resolve the path to current module. 2370 if (saved_jvm_path[0] != 0) { 2371 strcpy(buf, saved_jvm_path); 2372 return; 2373 } 2374 2375 char dli_fname[MAXPATHLEN]; 2376 bool ret = dll_address_to_library_name( 2377 CAST_FROM_FN_PTR(address, os::jvm_path), 2378 dli_fname, sizeof(dli_fname), NULL); 2379 assert(ret, "cannot locate libjvm"); 2380 char *rp = NULL; 2381 if (ret && dli_fname[0] != '\0') { 2382 rp = os::Posix::realpath(dli_fname, buf, buflen); 2383 } 2384 if (rp == NULL) { 2385 return; 2386 } 2387 2388 if (Arguments::sun_java_launcher_is_altjvm()) { 2389 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 2390 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so". 2391 // If "/jre/lib/" appears at the right place in the string, then 2392 // assume we are installed in a JDK and we're done. Otherwise, check 2393 // for a JAVA_HOME environment variable and fix up the path so it 2394 // looks like libjvm.so is installed there (append a fake suffix 2395 // hotspot/libjvm.so). 2396 const char *p = buf + strlen(buf) - 1; 2397 for (int count = 0; p > buf && count < 5; ++count) { 2398 for (--p; p > buf && *p != '/'; --p) 2399 /* empty */ ; 2400 } 2401 2402 if (strncmp(p, "/jre/lib/", 9) != 0) { 2403 // Look for JAVA_HOME in the environment. 2404 char* java_home_var = ::getenv("JAVA_HOME"); 2405 if (java_home_var != NULL && java_home_var[0] != 0) { 2406 char* jrelib_p; 2407 int len; 2408 2409 // Check the current module name "libjvm.so". 2410 p = strrchr(buf, '/'); 2411 if (p == NULL) { 2412 return; 2413 } 2414 assert(strstr(p, "/libjvm") == p, "invalid library name"); 2415 2416 rp = os::Posix::realpath(java_home_var, buf, buflen); 2417 if (rp == NULL) { 2418 return; 2419 } 2420 2421 // determine if this is a legacy image or modules image 2422 // modules image doesn't have "jre" subdirectory 2423 len = strlen(buf); 2424 assert(len < buflen, "Ran out of buffer room"); 2425 jrelib_p = buf + len; 2426 snprintf(jrelib_p, buflen-len, "/jre/lib"); 2427 if (0 != access(buf, F_OK)) { 2428 snprintf(jrelib_p, buflen-len, "/lib"); 2429 } 2430 2431 if (0 == access(buf, F_OK)) { 2432 // Use current module name "libjvm.so" 2433 len = strlen(buf); 2434 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so"); 2435 } else { 2436 // Go back to path of .so 2437 rp = os::Posix::realpath(dli_fname, buf, buflen); 2438 if (rp == NULL) { 2439 return; 2440 } 2441 } 2442 } 2443 } 2444 } 2445 2446 strncpy(saved_jvm_path, buf, MAXPATHLEN); 2447 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 2448 } 2449 2450 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 2451 // no prefix required, not even "_" 2452 } 2453 2454 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 2455 // no suffix required 2456 } 2457 2458 //////////////////////////////////////////////////////////////////////////////// 2459 // sun.misc.Signal support 2460 2461 static volatile jint sigint_count = 0; 2462 2463 static void UserHandler(int sig, void *siginfo, void *context) { 2464 // 4511530 - sem_post is serialized and handled by the manager thread. When 2465 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 2466 // don't want to flood the manager thread with sem_post requests. 2467 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 2468 return; 2469 } 2470 2471 // Ctrl-C is pressed during error reporting, likely because the error 2472 // handler fails to abort. Let VM die immediately. 2473 if (sig == SIGINT && VMError::is_error_reported()) { 2474 os::die(); 2475 } 2476 2477 os::signal_notify(sig); 2478 } 2479 2480 void* os::user_handler() { 2481 return CAST_FROM_FN_PTR(void*, UserHandler); 2482 } 2483 2484 static struct timespec create_semaphore_timespec(unsigned int sec, int nsec) { 2485 struct timespec ts; 2486 // Semaphore's are always associated with CLOCK_REALTIME 2487 os::Linux::clock_gettime(CLOCK_REALTIME, &ts); 2488 // see os_posix.cpp for discussion on overflow checking 2489 if (sec >= MAX_SECS) { 2490 ts.tv_sec += MAX_SECS; 2491 ts.tv_nsec = 0; 2492 } else { 2493 ts.tv_sec += sec; 2494 ts.tv_nsec += nsec; 2495 if (ts.tv_nsec >= NANOSECS_PER_SEC) { 2496 ts.tv_nsec -= NANOSECS_PER_SEC; 2497 ++ts.tv_sec; // note: this must be <= max_secs 2498 } 2499 } 2500 2501 return ts; 2502 } 2503 2504 extern "C" { 2505 typedef void (*sa_handler_t)(int); 2506 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 2507 } 2508 2509 void* os::signal(int signal_number, void* handler) { 2510 struct sigaction sigAct, oldSigAct; 2511 2512 sigfillset(&(sigAct.sa_mask)); 2513 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 2514 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 2515 2516 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 2517 // -1 means registration failed 2518 return (void *)-1; 2519 } 2520 2521 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 2522 } 2523 2524 void os::signal_raise(int signal_number) { 2525 ::raise(signal_number); 2526 } 2527 2528 // The following code is moved from os.cpp for making this 2529 // code platform specific, which it is by its very nature. 2530 2531 // Will be modified when max signal is changed to be dynamic 2532 int os::sigexitnum_pd() { 2533 return NSIG; 2534 } 2535 2536 // a counter for each possible signal value 2537 static volatile jint pending_signals[NSIG+1] = { 0 }; 2538 2539 // Linux(POSIX) specific hand shaking semaphore. 2540 static Semaphore* sig_sem = NULL; 2541 static PosixSemaphore sr_semaphore; 2542 2543 static void jdk_misc_signal_init() { 2544 // Initialize signal structures 2545 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2546 2547 // Initialize signal semaphore 2548 sig_sem = new Semaphore(); 2549 } 2550 2551 void os::signal_notify(int sig) { 2552 if (sig_sem != NULL) { 2553 Atomic::inc(&pending_signals[sig]); 2554 sig_sem->signal(); 2555 } else { 2556 // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init 2557 // initialization isn't called. 2558 assert(ReduceSignalUsage, "signal semaphore should be created"); 2559 } 2560 } 2561 2562 static int check_pending_signals() { 2563 Atomic::store(0, &sigint_count); 2564 for (;;) { 2565 for (int i = 0; i < NSIG + 1; i++) { 2566 jint n = pending_signals[i]; 2567 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2568 return i; 2569 } 2570 } 2571 JavaThread *thread = JavaThread::current(); 2572 ThreadBlockInVM tbivm(thread); 2573 2574 bool threadIsSuspended; 2575 do { 2576 thread->set_suspend_equivalent(); 2577 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2578 sig_sem->wait(); 2579 2580 // were we externally suspended while we were waiting? 2581 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2582 if (threadIsSuspended) { 2583 // The semaphore has been incremented, but while we were waiting 2584 // another thread suspended us. We don't want to continue running 2585 // while suspended because that would surprise the thread that 2586 // suspended us. 2587 sig_sem->signal(); 2588 2589 thread->java_suspend_self(); 2590 } 2591 } while (threadIsSuspended); 2592 } 2593 } 2594 2595 int os::signal_wait() { 2596 return check_pending_signals(); 2597 } 2598 2599 //////////////////////////////////////////////////////////////////////////////// 2600 // Virtual Memory 2601 2602 int os::vm_page_size() { 2603 // Seems redundant as all get out 2604 assert(os::Linux::page_size() != -1, "must call os::init"); 2605 return os::Linux::page_size(); 2606 } 2607 2608 // Solaris allocates memory by pages. 2609 int os::vm_allocation_granularity() { 2610 assert(os::Linux::page_size() != -1, "must call os::init"); 2611 return os::Linux::page_size(); 2612 } 2613 2614 // Rationale behind this function: 2615 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2616 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2617 // samples for JITted code. Here we create private executable mapping over the code cache 2618 // and then we can use standard (well, almost, as mapping can change) way to provide 2619 // info for the reporting script by storing timestamp and location of symbol 2620 void linux_wrap_code(char* base, size_t size) { 2621 static volatile jint cnt = 0; 2622 2623 if (!UseOprofile) { 2624 return; 2625 } 2626 2627 char buf[PATH_MAX+1]; 2628 int num = Atomic::add(1, &cnt); 2629 2630 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d", 2631 os::get_temp_directory(), os::current_process_id(), num); 2632 unlink(buf); 2633 2634 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2635 2636 if (fd != -1) { 2637 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2638 if (rv != (off_t)-1) { 2639 if (::write(fd, "", 1) == 1) { 2640 mmap(base, size, 2641 PROT_READ|PROT_WRITE|PROT_EXEC, 2642 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2643 } 2644 } 2645 ::close(fd); 2646 unlink(buf); 2647 } 2648 } 2649 2650 static bool recoverable_mmap_error(int err) { 2651 // See if the error is one we can let the caller handle. This 2652 // list of errno values comes from JBS-6843484. I can't find a 2653 // Linux man page that documents this specific set of errno 2654 // values so while this list currently matches Solaris, it may 2655 // change as we gain experience with this failure mode. 2656 switch (err) { 2657 case EBADF: 2658 case EINVAL: 2659 case ENOTSUP: 2660 // let the caller deal with these errors 2661 return true; 2662 2663 default: 2664 // Any remaining errors on this OS can cause our reserved mapping 2665 // to be lost. That can cause confusion where different data 2666 // structures think they have the same memory mapped. The worst 2667 // scenario is if both the VM and a library think they have the 2668 // same memory mapped. 2669 return false; 2670 } 2671 } 2672 2673 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2674 int err) { 2675 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2676 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec, 2677 os::strerror(err), err); 2678 } 2679 2680 static void warn_fail_commit_memory(char* addr, size_t size, 2681 size_t alignment_hint, bool exec, 2682 int err) { 2683 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2684 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, 2685 alignment_hint, exec, os::strerror(err), err); 2686 } 2687 2688 // NOTE: Linux kernel does not really reserve the pages for us. 2689 // All it does is to check if there are enough free pages 2690 // left at the time of mmap(). This could be a potential 2691 // problem. 2692 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) { 2693 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2694 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2695 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2696 if (res != (uintptr_t) MAP_FAILED) { 2697 if (UseNUMAInterleaving) { 2698 numa_make_global(addr, size); 2699 } 2700 return 0; 2701 } 2702 2703 int err = errno; // save errno from mmap() call above 2704 2705 if (!recoverable_mmap_error(err)) { 2706 warn_fail_commit_memory(addr, size, exec, err); 2707 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory."); 2708 } 2709 2710 return err; 2711 } 2712 2713 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2714 return os::Linux::commit_memory_impl(addr, size, exec) == 0; 2715 } 2716 2717 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2718 const char* mesg) { 2719 assert(mesg != NULL, "mesg must be specified"); 2720 int err = os::Linux::commit_memory_impl(addr, size, exec); 2721 if (err != 0) { 2722 // the caller wants all commit errors to exit with the specified mesg: 2723 warn_fail_commit_memory(addr, size, exec, err); 2724 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2725 } 2726 } 2727 2728 // Define MAP_HUGETLB here so we can build HotSpot on old systems. 2729 #ifndef MAP_HUGETLB 2730 #define MAP_HUGETLB 0x40000 2731 #endif 2732 2733 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems. 2734 #ifndef MADV_HUGEPAGE 2735 #define MADV_HUGEPAGE 14 2736 #endif 2737 2738 int os::Linux::commit_memory_impl(char* addr, size_t size, 2739 size_t alignment_hint, bool exec) { 2740 int err = os::Linux::commit_memory_impl(addr, size, exec); 2741 if (err == 0) { 2742 realign_memory(addr, size, alignment_hint); 2743 } 2744 return err; 2745 } 2746 2747 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2748 bool exec) { 2749 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0; 2750 } 2751 2752 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2753 size_t alignment_hint, bool exec, 2754 const char* mesg) { 2755 assert(mesg != NULL, "mesg must be specified"); 2756 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec); 2757 if (err != 0) { 2758 // the caller wants all commit errors to exit with the specified mesg: 2759 warn_fail_commit_memory(addr, size, alignment_hint, exec, err); 2760 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2761 } 2762 } 2763 2764 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2765 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) { 2766 // We don't check the return value: madvise(MADV_HUGEPAGE) may not 2767 // be supported or the memory may already be backed by huge pages. 2768 ::madvise(addr, bytes, MADV_HUGEPAGE); 2769 } 2770 } 2771 2772 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2773 // This method works by doing an mmap over an existing mmaping and effectively discarding 2774 // the existing pages. However it won't work for SHM-based large pages that cannot be 2775 // uncommitted at all. We don't do anything in this case to avoid creating a segment with 2776 // small pages on top of the SHM segment. This method always works for small pages, so we 2777 // allow that in any case. 2778 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) { 2779 commit_memory(addr, bytes, alignment_hint, !ExecMem); 2780 } 2781 } 2782 2783 void os::numa_make_global(char *addr, size_t bytes) { 2784 Linux::numa_interleave_memory(addr, bytes); 2785 } 2786 2787 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the 2788 // bind policy to MPOL_PREFERRED for the current thread. 2789 #define USE_MPOL_PREFERRED 0 2790 2791 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2792 // To make NUMA and large pages more robust when both enabled, we need to ease 2793 // the requirements on where the memory should be allocated. MPOL_BIND is the 2794 // default policy and it will force memory to be allocated on the specified 2795 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on 2796 // the specified node, but will not force it. Using this policy will prevent 2797 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no 2798 // free large pages. 2799 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED); 2800 Linux::numa_tonode_memory(addr, bytes, lgrp_hint); 2801 } 2802 2803 bool os::numa_topology_changed() { return false; } 2804 2805 size_t os::numa_get_groups_num() { 2806 // Return just the number of nodes in which it's possible to allocate memory 2807 // (in numa terminology, configured nodes). 2808 return Linux::numa_num_configured_nodes(); 2809 } 2810 2811 int os::numa_get_group_id() { 2812 int cpu_id = Linux::sched_getcpu(); 2813 if (cpu_id != -1) { 2814 int lgrp_id = Linux::get_node_by_cpu(cpu_id); 2815 if (lgrp_id != -1) { 2816 return lgrp_id; 2817 } 2818 } 2819 return 0; 2820 } 2821 2822 int os::Linux::get_existing_num_nodes() { 2823 size_t node; 2824 size_t highest_node_number = Linux::numa_max_node(); 2825 int num_nodes = 0; 2826 2827 // Get the total number of nodes in the system including nodes without memory. 2828 for (node = 0; node <= highest_node_number; node++) { 2829 if (isnode_in_existing_nodes(node)) { 2830 num_nodes++; 2831 } 2832 } 2833 return num_nodes; 2834 } 2835 2836 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2837 size_t highest_node_number = Linux::numa_max_node(); 2838 size_t i = 0; 2839 2840 // Map all node ids in which is possible to allocate memory. Also nodes are 2841 // not always consecutively available, i.e. available from 0 to the highest 2842 // node number. If the nodes have been bound explicitly using numactl membind, 2843 // then allocate memory from those nodes only. 2844 for (size_t node = 0; node <= highest_node_number; node++) { 2845 if (Linux::isnode_in_bound_nodes(node)) { 2846 ids[i++] = node; 2847 } 2848 } 2849 return i; 2850 } 2851 2852 bool os::get_page_info(char *start, page_info* info) { 2853 return false; 2854 } 2855 2856 char *os::scan_pages(char *start, char* end, page_info* page_expected, 2857 page_info* page_found) { 2858 return end; 2859 } 2860 2861 2862 int os::Linux::sched_getcpu_syscall(void) { 2863 unsigned int cpu = 0; 2864 int retval = -1; 2865 2866 #if defined(IA32) 2867 #ifndef SYS_getcpu 2868 #define SYS_getcpu 318 2869 #endif 2870 retval = syscall(SYS_getcpu, &cpu, NULL, NULL); 2871 #elif defined(AMD64) 2872 // Unfortunately we have to bring all these macros here from vsyscall.h 2873 // to be able to compile on old linuxes. 2874 #define __NR_vgetcpu 2 2875 #define VSYSCALL_START (-10UL << 20) 2876 #define VSYSCALL_SIZE 1024 2877 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr)) 2878 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache); 2879 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu); 2880 retval = vgetcpu(&cpu, NULL, NULL); 2881 #endif 2882 2883 return (retval == -1) ? retval : cpu; 2884 } 2885 2886 void os::Linux::sched_getcpu_init() { 2887 // sched_getcpu() should be in libc. 2888 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2889 dlsym(RTLD_DEFAULT, "sched_getcpu"))); 2890 2891 // If it's not, try a direct syscall. 2892 if (sched_getcpu() == -1) { 2893 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2894 (void*)&sched_getcpu_syscall)); 2895 } 2896 2897 if (sched_getcpu() == -1) { 2898 vm_exit_during_initialization("getcpu(2) system call not supported by kernel"); 2899 } 2900 } 2901 2902 // Something to do with the numa-aware allocator needs these symbols 2903 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { } 2904 extern "C" JNIEXPORT void numa_error(char *where) { } 2905 2906 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails 2907 // load symbol from base version instead. 2908 void* os::Linux::libnuma_dlsym(void* handle, const char *name) { 2909 void *f = dlvsym(handle, name, "libnuma_1.1"); 2910 if (f == NULL) { 2911 f = dlsym(handle, name); 2912 } 2913 return f; 2914 } 2915 2916 // Handle request to load libnuma symbol version 1.2 (API v2) only. 2917 // Return NULL if the symbol is not defined in this particular version. 2918 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) { 2919 return dlvsym(handle, name, "libnuma_1.2"); 2920 } 2921 2922 bool os::Linux::libnuma_init() { 2923 if (sched_getcpu() != -1) { // Requires sched_getcpu() support 2924 void *handle = dlopen("libnuma.so.1", RTLD_LAZY); 2925 if (handle != NULL) { 2926 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, 2927 libnuma_dlsym(handle, "numa_node_to_cpus"))); 2928 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, 2929 libnuma_dlsym(handle, "numa_max_node"))); 2930 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t, 2931 libnuma_dlsym(handle, "numa_num_configured_nodes"))); 2932 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, 2933 libnuma_dlsym(handle, "numa_available"))); 2934 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, 2935 libnuma_dlsym(handle, "numa_tonode_memory"))); 2936 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t, 2937 libnuma_dlsym(handle, "numa_interleave_memory"))); 2938 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t, 2939 libnuma_v2_dlsym(handle, "numa_interleave_memory"))); 2940 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t, 2941 libnuma_dlsym(handle, "numa_set_bind_policy"))); 2942 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t, 2943 libnuma_dlsym(handle, "numa_bitmask_isbitset"))); 2944 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t, 2945 libnuma_dlsym(handle, "numa_distance"))); 2946 set_numa_get_membind(CAST_TO_FN_PTR(numa_get_membind_func_t, 2947 libnuma_v2_dlsym(handle, "numa_get_membind"))); 2948 2949 if (numa_available() != -1) { 2950 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); 2951 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr")); 2952 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr")); 2953 // Create an index -> node mapping, since nodes are not always consecutive 2954 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2955 rebuild_nindex_to_node_map(); 2956 // Create a cpu -> node mapping 2957 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2958 rebuild_cpu_to_node_map(); 2959 return true; 2960 } 2961 } 2962 } 2963 return false; 2964 } 2965 2966 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 2967 // Creating guard page is very expensive. Java thread has HotSpot 2968 // guard pages, only enable glibc guard page for non-Java threads. 2969 // (Remember: compiler thread is a Java thread, too!) 2970 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size()); 2971 } 2972 2973 void os::Linux::rebuild_nindex_to_node_map() { 2974 int highest_node_number = Linux::numa_max_node(); 2975 2976 nindex_to_node()->clear(); 2977 for (int node = 0; node <= highest_node_number; node++) { 2978 if (Linux::isnode_in_existing_nodes(node)) { 2979 nindex_to_node()->append(node); 2980 } 2981 } 2982 } 2983 2984 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. 2985 // The table is later used in get_node_by_cpu(). 2986 void os::Linux::rebuild_cpu_to_node_map() { 2987 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure 2988 // in libnuma (possible values are starting from 16, 2989 // and continuing up with every other power of 2, but less 2990 // than the maximum number of CPUs supported by kernel), and 2991 // is a subject to change (in libnuma version 2 the requirements 2992 // are more reasonable) we'll just hardcode the number they use 2993 // in the library. 2994 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT; 2995 2996 size_t cpu_num = processor_count(); 2997 size_t cpu_map_size = NCPUS / BitsPerCLong; 2998 size_t cpu_map_valid_size = 2999 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size); 3000 3001 cpu_to_node()->clear(); 3002 cpu_to_node()->at_grow(cpu_num - 1); 3003 3004 size_t node_num = get_existing_num_nodes(); 3005 3006 int distance = 0; 3007 int closest_distance = INT_MAX; 3008 int closest_node = 0; 3009 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal); 3010 for (size_t i = 0; i < node_num; i++) { 3011 // Check if node is configured (not a memory-less node). If it is not, find 3012 // the closest configured node. Check also if node is bound, i.e. it's allowed 3013 // to allocate memory from the node. If it's not allowed, map cpus in that node 3014 // to the closest node from which memory allocation is allowed. 3015 if (!isnode_in_configured_nodes(nindex_to_node()->at(i)) || 3016 !isnode_in_bound_nodes(nindex_to_node()->at(i))) { 3017 closest_distance = INT_MAX; 3018 // Check distance from all remaining nodes in the system. Ignore distance 3019 // from itself, from another non-configured node, and from another non-bound 3020 // node. 3021 for (size_t m = 0; m < node_num; m++) { 3022 if (m != i && 3023 isnode_in_configured_nodes(nindex_to_node()->at(m)) && 3024 isnode_in_bound_nodes(nindex_to_node()->at(m))) { 3025 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m)); 3026 // If a closest node is found, update. There is always at least one 3027 // configured and bound node in the system so there is always at least 3028 // one node close. 3029 if (distance != 0 && distance < closest_distance) { 3030 closest_distance = distance; 3031 closest_node = nindex_to_node()->at(m); 3032 } 3033 } 3034 } 3035 } else { 3036 // Current node is already a configured node. 3037 closest_node = nindex_to_node()->at(i); 3038 } 3039 3040 // Get cpus from the original node and map them to the closest node. If node 3041 // is a configured node (not a memory-less node), then original node and 3042 // closest node are the same. 3043 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { 3044 for (size_t j = 0; j < cpu_map_valid_size; j++) { 3045 if (cpu_map[j] != 0) { 3046 for (size_t k = 0; k < BitsPerCLong; k++) { 3047 if (cpu_map[j] & (1UL << k)) { 3048 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node); 3049 } 3050 } 3051 } 3052 } 3053 } 3054 } 3055 FREE_C_HEAP_ARRAY(unsigned long, cpu_map); 3056 } 3057 3058 int os::Linux::get_node_by_cpu(int cpu_id) { 3059 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { 3060 return cpu_to_node()->at(cpu_id); 3061 } 3062 return -1; 3063 } 3064 3065 GrowableArray<int>* os::Linux::_cpu_to_node; 3066 GrowableArray<int>* os::Linux::_nindex_to_node; 3067 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu; 3068 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus; 3069 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node; 3070 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes; 3071 os::Linux::numa_available_func_t os::Linux::_numa_available; 3072 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory; 3073 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory; 3074 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2; 3075 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy; 3076 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset; 3077 os::Linux::numa_distance_func_t os::Linux::_numa_distance; 3078 os::Linux::numa_get_membind_func_t os::Linux::_numa_get_membind; 3079 unsigned long* os::Linux::_numa_all_nodes; 3080 struct bitmask* os::Linux::_numa_all_nodes_ptr; 3081 struct bitmask* os::Linux::_numa_nodes_ptr; 3082 3083 bool os::pd_uncommit_memory(char* addr, size_t size) { 3084 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 3085 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 3086 return res != (uintptr_t) MAP_FAILED; 3087 } 3088 3089 static address get_stack_commited_bottom(address bottom, size_t size) { 3090 address nbot = bottom; 3091 address ntop = bottom + size; 3092 3093 size_t page_sz = os::vm_page_size(); 3094 unsigned pages = size / page_sz; 3095 3096 unsigned char vec[1]; 3097 unsigned imin = 1, imax = pages + 1, imid; 3098 int mincore_return_value = 0; 3099 3100 assert(imin <= imax, "Unexpected page size"); 3101 3102 while (imin < imax) { 3103 imid = (imax + imin) / 2; 3104 nbot = ntop - (imid * page_sz); 3105 3106 // Use a trick with mincore to check whether the page is mapped or not. 3107 // mincore sets vec to 1 if page resides in memory and to 0 if page 3108 // is swapped output but if page we are asking for is unmapped 3109 // it returns -1,ENOMEM 3110 mincore_return_value = mincore(nbot, page_sz, vec); 3111 3112 if (mincore_return_value == -1) { 3113 // Page is not mapped go up 3114 // to find first mapped page 3115 if (errno != EAGAIN) { 3116 assert(errno == ENOMEM, "Unexpected mincore errno"); 3117 imax = imid; 3118 } 3119 } else { 3120 // Page is mapped go down 3121 // to find first not mapped page 3122 imin = imid + 1; 3123 } 3124 } 3125 3126 nbot = nbot + page_sz; 3127 3128 // Adjust stack bottom one page up if last checked page is not mapped 3129 if (mincore_return_value == -1) { 3130 nbot = nbot + page_sz; 3131 } 3132 3133 return nbot; 3134 } 3135 3136 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) { 3137 int mincore_return_value; 3138 const size_t stripe = 1024; // query this many pages each time 3139 unsigned char vec[stripe + 1]; 3140 // set a guard 3141 vec[stripe] = 'X'; 3142 3143 const size_t page_sz = os::vm_page_size(); 3144 size_t pages = size / page_sz; 3145 3146 assert(is_aligned(start, page_sz), "Start address must be page aligned"); 3147 assert(is_aligned(size, page_sz), "Size must be page aligned"); 3148 3149 committed_start = NULL; 3150 3151 int loops = (pages + stripe - 1) / stripe; 3152 int committed_pages = 0; 3153 address loop_base = start; 3154 bool found_range = false; 3155 3156 for (int index = 0; index < loops && !found_range; index ++) { 3157 assert(pages > 0, "Nothing to do"); 3158 int pages_to_query = (pages >= stripe) ? stripe : pages; 3159 pages -= pages_to_query; 3160 3161 // Get stable read 3162 while ((mincore_return_value = mincore(loop_base, pages_to_query * page_sz, vec)) == -1 && errno == EAGAIN); 3163 3164 // During shutdown, some memory goes away without properly notifying NMT, 3165 // E.g. ConcurrentGCThread/WatcherThread can exit without deleting thread object. 3166 // Bailout and return as not committed for now. 3167 if (mincore_return_value == -1 && errno == ENOMEM) { 3168 return false; 3169 } 3170 3171 assert(vec[stripe] == 'X', "overflow guard"); 3172 assert(mincore_return_value == 0, "Range must be valid"); 3173 // Process this stripe 3174 for (int vecIdx = 0; vecIdx < pages_to_query; vecIdx ++) { 3175 if ((vec[vecIdx] & 0x01) == 0) { // not committed 3176 // End of current contiguous region 3177 if (committed_start != NULL) { 3178 found_range = true; 3179 break; 3180 } 3181 } else { // committed 3182 // Start of region 3183 if (committed_start == NULL) { 3184 committed_start = loop_base + page_sz * vecIdx; 3185 } 3186 committed_pages ++; 3187 } 3188 } 3189 3190 loop_base += pages_to_query * page_sz; 3191 } 3192 3193 if (committed_start != NULL) { 3194 assert(committed_pages > 0, "Must have committed region"); 3195 assert(committed_pages <= int(size / page_sz), "Can not commit more than it has"); 3196 assert(committed_start >= start && committed_start < start + size, "Out of range"); 3197 committed_size = page_sz * committed_pages; 3198 return true; 3199 } else { 3200 assert(committed_pages == 0, "Should not have committed region"); 3201 return false; 3202 } 3203 } 3204 3205 3206 // Linux uses a growable mapping for the stack, and if the mapping for 3207 // the stack guard pages is not removed when we detach a thread the 3208 // stack cannot grow beyond the pages where the stack guard was 3209 // mapped. If at some point later in the process the stack expands to 3210 // that point, the Linux kernel cannot expand the stack any further 3211 // because the guard pages are in the way, and a segfault occurs. 3212 // 3213 // However, it's essential not to split the stack region by unmapping 3214 // a region (leaving a hole) that's already part of the stack mapping, 3215 // so if the stack mapping has already grown beyond the guard pages at 3216 // the time we create them, we have to truncate the stack mapping. 3217 // So, we need to know the extent of the stack mapping when 3218 // create_stack_guard_pages() is called. 3219 3220 // We only need this for stacks that are growable: at the time of 3221 // writing thread stacks don't use growable mappings (i.e. those 3222 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this 3223 // only applies to the main thread. 3224 3225 // If the (growable) stack mapping already extends beyond the point 3226 // where we're going to put our guard pages, truncate the mapping at 3227 // that point by munmap()ping it. This ensures that when we later 3228 // munmap() the guard pages we don't leave a hole in the stack 3229 // mapping. This only affects the main/primordial thread 3230 3231 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 3232 if (os::is_primordial_thread()) { 3233 // As we manually grow stack up to bottom inside create_attached_thread(), 3234 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and 3235 // we don't need to do anything special. 3236 // Check it first, before calling heavy function. 3237 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom(); 3238 unsigned char vec[1]; 3239 3240 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) { 3241 // Fallback to slow path on all errors, including EAGAIN 3242 stack_extent = (uintptr_t) get_stack_commited_bottom( 3243 os::Linux::initial_thread_stack_bottom(), 3244 (size_t)addr - stack_extent); 3245 } 3246 3247 if (stack_extent < (uintptr_t)addr) { 3248 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent)); 3249 } 3250 } 3251 3252 return os::commit_memory(addr, size, !ExecMem); 3253 } 3254 3255 // If this is a growable mapping, remove the guard pages entirely by 3256 // munmap()ping them. If not, just call uncommit_memory(). This only 3257 // affects the main/primordial thread, but guard against future OS changes. 3258 // It's safe to always unmap guard pages for primordial thread because we 3259 // always place it right after end of the mapped region. 3260 3261 bool os::remove_stack_guard_pages(char* addr, size_t size) { 3262 uintptr_t stack_extent, stack_base; 3263 3264 if (os::is_primordial_thread()) { 3265 return ::munmap(addr, size) == 0; 3266 } 3267 3268 return os::uncommit_memory(addr, size); 3269 } 3270 3271 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 3272 // at 'requested_addr'. If there are existing memory mappings at the same 3273 // location, however, they will be overwritten. If 'fixed' is false, 3274 // 'requested_addr' is only treated as a hint, the return value may or 3275 // may not start from the requested address. Unlike Linux mmap(), this 3276 // function returns NULL to indicate failure. 3277 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 3278 char * addr; 3279 int flags; 3280 3281 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 3282 if (fixed) { 3283 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address"); 3284 flags |= MAP_FIXED; 3285 } 3286 3287 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 3288 // touch an uncommitted page. Otherwise, the read/write might 3289 // succeed if we have enough swap space to back the physical page. 3290 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 3291 flags, -1, 0); 3292 3293 return addr == MAP_FAILED ? NULL : addr; 3294 } 3295 3296 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address 3297 // (req_addr != NULL) or with a given alignment. 3298 // - bytes shall be a multiple of alignment. 3299 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3300 // - alignment sets the alignment at which memory shall be allocated. 3301 // It must be a multiple of allocation granularity. 3302 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3303 // req_addr or NULL. 3304 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) { 3305 3306 size_t extra_size = bytes; 3307 if (req_addr == NULL && alignment > 0) { 3308 extra_size += alignment; 3309 } 3310 3311 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE, 3312 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 3313 -1, 0); 3314 if (start == MAP_FAILED) { 3315 start = NULL; 3316 } else { 3317 if (req_addr != NULL) { 3318 if (start != req_addr) { 3319 ::munmap(start, extra_size); 3320 start = NULL; 3321 } 3322 } else { 3323 char* const start_aligned = align_up(start, alignment); 3324 char* const end_aligned = start_aligned + bytes; 3325 char* const end = start + extra_size; 3326 if (start_aligned > start) { 3327 ::munmap(start, start_aligned - start); 3328 } 3329 if (end_aligned < end) { 3330 ::munmap(end_aligned, end - end_aligned); 3331 } 3332 start = start_aligned; 3333 } 3334 } 3335 return start; 3336 } 3337 3338 static int anon_munmap(char * addr, size_t size) { 3339 return ::munmap(addr, size) == 0; 3340 } 3341 3342 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 3343 size_t alignment_hint) { 3344 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 3345 } 3346 3347 bool os::pd_release_memory(char* addr, size_t size) { 3348 return anon_munmap(addr, size); 3349 } 3350 3351 static bool linux_mprotect(char* addr, size_t size, int prot) { 3352 // Linux wants the mprotect address argument to be page aligned. 3353 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size()); 3354 3355 // According to SUSv3, mprotect() should only be used with mappings 3356 // established by mmap(), and mmap() always maps whole pages. Unaligned 3357 // 'addr' likely indicates problem in the VM (e.g. trying to change 3358 // protection of malloc'ed or statically allocated memory). Check the 3359 // caller if you hit this assert. 3360 assert(addr == bottom, "sanity check"); 3361 3362 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size()); 3363 return ::mprotect(bottom, size, prot) == 0; 3364 } 3365 3366 // Set protections specified 3367 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 3368 bool is_committed) { 3369 unsigned int p = 0; 3370 switch (prot) { 3371 case MEM_PROT_NONE: p = PROT_NONE; break; 3372 case MEM_PROT_READ: p = PROT_READ; break; 3373 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 3374 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 3375 default: 3376 ShouldNotReachHere(); 3377 } 3378 // is_committed is unused. 3379 return linux_mprotect(addr, bytes, p); 3380 } 3381 3382 bool os::guard_memory(char* addr, size_t size) { 3383 return linux_mprotect(addr, size, PROT_NONE); 3384 } 3385 3386 bool os::unguard_memory(char* addr, size_t size) { 3387 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE); 3388 } 3389 3390 bool os::Linux::transparent_huge_pages_sanity_check(bool warn, 3391 size_t page_size) { 3392 bool result = false; 3393 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE, 3394 MAP_ANONYMOUS|MAP_PRIVATE, 3395 -1, 0); 3396 if (p != MAP_FAILED) { 3397 void *aligned_p = align_up(p, page_size); 3398 3399 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0; 3400 3401 munmap(p, page_size * 2); 3402 } 3403 3404 if (warn && !result) { 3405 warning("TransparentHugePages is not supported by the operating system."); 3406 } 3407 3408 return result; 3409 } 3410 3411 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) { 3412 bool result = false; 3413 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE, 3414 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, 3415 -1, 0); 3416 3417 if (p != MAP_FAILED) { 3418 // We don't know if this really is a huge page or not. 3419 FILE *fp = fopen("/proc/self/maps", "r"); 3420 if (fp) { 3421 while (!feof(fp)) { 3422 char chars[257]; 3423 long x = 0; 3424 if (fgets(chars, sizeof(chars), fp)) { 3425 if (sscanf(chars, "%lx-%*x", &x) == 1 3426 && x == (long)p) { 3427 if (strstr (chars, "hugepage")) { 3428 result = true; 3429 break; 3430 } 3431 } 3432 } 3433 } 3434 fclose(fp); 3435 } 3436 munmap(p, page_size); 3437 } 3438 3439 if (warn && !result) { 3440 warning("HugeTLBFS is not supported by the operating system."); 3441 } 3442 3443 return result; 3444 } 3445 3446 // Set the coredump_filter bits to include largepages in core dump (bit 6) 3447 // 3448 // From the coredump_filter documentation: 3449 // 3450 // - (bit 0) anonymous private memory 3451 // - (bit 1) anonymous shared memory 3452 // - (bit 2) file-backed private memory 3453 // - (bit 3) file-backed shared memory 3454 // - (bit 4) ELF header pages in file-backed private memory areas (it is 3455 // effective only if the bit 2 is cleared) 3456 // - (bit 5) hugetlb private memory 3457 // - (bit 6) hugetlb shared memory 3458 // - (bit 7) dax private memory 3459 // - (bit 8) dax shared memory 3460 // 3461 static void set_coredump_filter(bool largepages, bool dax_shared) { 3462 FILE *f; 3463 long cdm; 3464 bool filter_changed = false; 3465 3466 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { 3467 return; 3468 } 3469 3470 if (fscanf(f, "%lx", &cdm) != 1) { 3471 fclose(f); 3472 return; 3473 } 3474 3475 rewind(f); 3476 3477 if (largepages && (cdm & LARGEPAGES_BIT) == 0) { 3478 cdm |= LARGEPAGES_BIT; 3479 filter_changed = true; 3480 } 3481 if (dax_shared && (cdm & DAX_SHARED_BIT) == 0) { 3482 cdm |= DAX_SHARED_BIT; 3483 filter_changed = true; 3484 } 3485 if (filter_changed) { 3486 fprintf(f, "%#lx", cdm); 3487 } 3488 3489 fclose(f); 3490 } 3491 3492 // Large page support 3493 3494 static size_t _large_page_size = 0; 3495 3496 size_t os::Linux::find_large_page_size() { 3497 size_t large_page_size = 0; 3498 3499 // large_page_size on Linux is used to round up heap size. x86 uses either 3500 // 2M or 4M page, depending on whether PAE (Physical Address Extensions) 3501 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use 3502 // page as large as 256M. 3503 // 3504 // Here we try to figure out page size by parsing /proc/meminfo and looking 3505 // for a line with the following format: 3506 // Hugepagesize: 2048 kB 3507 // 3508 // If we can't determine the value (e.g. /proc is not mounted, or the text 3509 // format has been changed), we'll use the largest page size supported by 3510 // the processor. 3511 3512 #ifndef ZERO 3513 large_page_size = 3514 AARCH64_ONLY(2 * M) 3515 AMD64_ONLY(2 * M) 3516 ARM32_ONLY(2 * M) 3517 IA32_ONLY(4 * M) 3518 IA64_ONLY(256 * M) 3519 PPC_ONLY(4 * M) 3520 S390_ONLY(1 * M) 3521 SPARC_ONLY(4 * M); 3522 #endif // ZERO 3523 3524 FILE *fp = fopen("/proc/meminfo", "r"); 3525 if (fp) { 3526 while (!feof(fp)) { 3527 int x = 0; 3528 char buf[16]; 3529 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { 3530 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { 3531 large_page_size = x * K; 3532 break; 3533 } 3534 } else { 3535 // skip to next line 3536 for (;;) { 3537 int ch = fgetc(fp); 3538 if (ch == EOF || ch == (int)'\n') break; 3539 } 3540 } 3541 } 3542 fclose(fp); 3543 } 3544 3545 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) { 3546 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is " 3547 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size), 3548 proper_unit_for_byte_size(large_page_size)); 3549 } 3550 3551 return large_page_size; 3552 } 3553 3554 size_t os::Linux::setup_large_page_size() { 3555 _large_page_size = Linux::find_large_page_size(); 3556 const size_t default_page_size = (size_t)Linux::page_size(); 3557 if (_large_page_size > default_page_size) { 3558 _page_sizes[0] = _large_page_size; 3559 _page_sizes[1] = default_page_size; 3560 _page_sizes[2] = 0; 3561 } 3562 3563 return _large_page_size; 3564 } 3565 3566 bool os::Linux::setup_large_page_type(size_t page_size) { 3567 if (FLAG_IS_DEFAULT(UseHugeTLBFS) && 3568 FLAG_IS_DEFAULT(UseSHM) && 3569 FLAG_IS_DEFAULT(UseTransparentHugePages)) { 3570 3571 // The type of large pages has not been specified by the user. 3572 3573 // Try UseHugeTLBFS and then UseSHM. 3574 UseHugeTLBFS = UseSHM = true; 3575 3576 // Don't try UseTransparentHugePages since there are known 3577 // performance issues with it turned on. This might change in the future. 3578 UseTransparentHugePages = false; 3579 } 3580 3581 if (UseTransparentHugePages) { 3582 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages); 3583 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) { 3584 UseHugeTLBFS = false; 3585 UseSHM = false; 3586 return true; 3587 } 3588 UseTransparentHugePages = false; 3589 } 3590 3591 if (UseHugeTLBFS) { 3592 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); 3593 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) { 3594 UseSHM = false; 3595 return true; 3596 } 3597 UseHugeTLBFS = false; 3598 } 3599 3600 return UseSHM; 3601 } 3602 3603 void os::large_page_init() { 3604 if (!UseLargePages && 3605 !UseTransparentHugePages && 3606 !UseHugeTLBFS && 3607 !UseSHM) { 3608 // Not using large pages. 3609 return; 3610 } 3611 3612 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) { 3613 // The user explicitly turned off large pages. 3614 // Ignore the rest of the large pages flags. 3615 UseTransparentHugePages = false; 3616 UseHugeTLBFS = false; 3617 UseSHM = false; 3618 return; 3619 } 3620 3621 size_t large_page_size = Linux::setup_large_page_size(); 3622 UseLargePages = Linux::setup_large_page_type(large_page_size); 3623 3624 set_coredump_filter(true /*largepages*/, false /*dax_shared*/); 3625 } 3626 3627 #ifndef SHM_HUGETLB 3628 #define SHM_HUGETLB 04000 3629 #endif 3630 3631 #define shm_warning_format(format, ...) \ 3632 do { \ 3633 if (UseLargePages && \ 3634 (!FLAG_IS_DEFAULT(UseLargePages) || \ 3635 !FLAG_IS_DEFAULT(UseSHM) || \ 3636 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \ 3637 warning(format, __VA_ARGS__); \ 3638 } \ 3639 } while (0) 3640 3641 #define shm_warning(str) shm_warning_format("%s", str) 3642 3643 #define shm_warning_with_errno(str) \ 3644 do { \ 3645 int err = errno; \ 3646 shm_warning_format(str " (error = %d)", err); \ 3647 } while (0) 3648 3649 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) { 3650 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment"); 3651 3652 if (!is_aligned(alignment, SHMLBA)) { 3653 assert(false, "Code below assumes that alignment is at least SHMLBA aligned"); 3654 return NULL; 3655 } 3656 3657 // To ensure that we get 'alignment' aligned memory from shmat, 3658 // we pre-reserve aligned virtual memory and then attach to that. 3659 3660 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL); 3661 if (pre_reserved_addr == NULL) { 3662 // Couldn't pre-reserve aligned memory. 3663 shm_warning("Failed to pre-reserve aligned memory for shmat."); 3664 return NULL; 3665 } 3666 3667 // SHM_REMAP is needed to allow shmat to map over an existing mapping. 3668 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP); 3669 3670 if ((intptr_t)addr == -1) { 3671 int err = errno; 3672 shm_warning_with_errno("Failed to attach shared memory."); 3673 3674 assert(err != EACCES, "Unexpected error"); 3675 assert(err != EIDRM, "Unexpected error"); 3676 assert(err != EINVAL, "Unexpected error"); 3677 3678 // Since we don't know if the kernel unmapped the pre-reserved memory area 3679 // we can't unmap it, since that would potentially unmap memory that was 3680 // mapped from other threads. 3681 return NULL; 3682 } 3683 3684 return addr; 3685 } 3686 3687 static char* shmat_at_address(int shmid, char* req_addr) { 3688 if (!is_aligned(req_addr, SHMLBA)) { 3689 assert(false, "Requested address needs to be SHMLBA aligned"); 3690 return NULL; 3691 } 3692 3693 char* addr = (char*)shmat(shmid, req_addr, 0); 3694 3695 if ((intptr_t)addr == -1) { 3696 shm_warning_with_errno("Failed to attach shared memory."); 3697 return NULL; 3698 } 3699 3700 return addr; 3701 } 3702 3703 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) { 3704 // If a req_addr has been provided, we assume that the caller has already aligned the address. 3705 if (req_addr != NULL) { 3706 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size"); 3707 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment"); 3708 return shmat_at_address(shmid, req_addr); 3709 } 3710 3711 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically 3712 // return large page size aligned memory addresses when req_addr == NULL. 3713 // However, if the alignment is larger than the large page size, we have 3714 // to manually ensure that the memory returned is 'alignment' aligned. 3715 if (alignment > os::large_page_size()) { 3716 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size"); 3717 return shmat_with_alignment(shmid, bytes, alignment); 3718 } else { 3719 return shmat_at_address(shmid, NULL); 3720 } 3721 } 3722 3723 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment, 3724 char* req_addr, bool exec) { 3725 // "exec" is passed in but not used. Creating the shared image for 3726 // the code cache doesn't have an SHM_X executable permission to check. 3727 assert(UseLargePages && UseSHM, "only for SHM large pages"); 3728 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3729 assert(is_aligned(req_addr, alignment), "Unaligned address"); 3730 3731 if (!is_aligned(bytes, os::large_page_size())) { 3732 return NULL; // Fallback to small pages. 3733 } 3734 3735 // Create a large shared memory region to attach to based on size. 3736 // Currently, size is the total size of the heap. 3737 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); 3738 if (shmid == -1) { 3739 // Possible reasons for shmget failure: 3740 // 1. shmmax is too small for Java heap. 3741 // > check shmmax value: cat /proc/sys/kernel/shmmax 3742 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 3743 // 2. not enough large page memory. 3744 // > check available large pages: cat /proc/meminfo 3745 // > increase amount of large pages: 3746 // echo new_value > /proc/sys/vm/nr_hugepages 3747 // Note 1: different Linux may use different name for this property, 3748 // e.g. on Redhat AS-3 it is "hugetlb_pool". 3749 // Note 2: it's possible there's enough physical memory available but 3750 // they are so fragmented after a long run that they can't 3751 // coalesce into large pages. Try to reserve large pages when 3752 // the system is still "fresh". 3753 shm_warning_with_errno("Failed to reserve shared memory."); 3754 return NULL; 3755 } 3756 3757 // Attach to the region. 3758 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr); 3759 3760 // Remove shmid. If shmat() is successful, the actual shared memory segment 3761 // will be deleted when it's detached by shmdt() or when the process 3762 // terminates. If shmat() is not successful this will remove the shared 3763 // segment immediately. 3764 shmctl(shmid, IPC_RMID, NULL); 3765 3766 return addr; 3767 } 3768 3769 static void warn_on_large_pages_failure(char* req_addr, size_t bytes, 3770 int error) { 3771 assert(error == ENOMEM, "Only expect to fail if no memory is available"); 3772 3773 bool warn_on_failure = UseLargePages && 3774 (!FLAG_IS_DEFAULT(UseLargePages) || 3775 !FLAG_IS_DEFAULT(UseHugeTLBFS) || 3776 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 3777 3778 if (warn_on_failure) { 3779 char msg[128]; 3780 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: " 3781 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error); 3782 warning("%s", msg); 3783 } 3784 } 3785 3786 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes, 3787 char* req_addr, 3788 bool exec) { 3789 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3790 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size"); 3791 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3792 3793 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3794 char* addr = (char*)::mmap(req_addr, bytes, prot, 3795 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, 3796 -1, 0); 3797 3798 if (addr == MAP_FAILED) { 3799 warn_on_large_pages_failure(req_addr, bytes, errno); 3800 return NULL; 3801 } 3802 3803 assert(is_aligned(addr, os::large_page_size()), "Must be"); 3804 3805 return addr; 3806 } 3807 3808 // Reserve memory using mmap(MAP_HUGETLB). 3809 // - bytes shall be a multiple of alignment. 3810 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3811 // - alignment sets the alignment at which memory shall be allocated. 3812 // It must be a multiple of allocation granularity. 3813 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3814 // req_addr or NULL. 3815 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes, 3816 size_t alignment, 3817 char* req_addr, 3818 bool exec) { 3819 size_t large_page_size = os::large_page_size(); 3820 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes"); 3821 3822 assert(is_aligned(req_addr, alignment), "Must be"); 3823 assert(is_aligned(bytes, alignment), "Must be"); 3824 3825 // First reserve - but not commit - the address range in small pages. 3826 char* const start = anon_mmap_aligned(bytes, alignment, req_addr); 3827 3828 if (start == NULL) { 3829 return NULL; 3830 } 3831 3832 assert(is_aligned(start, alignment), "Must be"); 3833 3834 char* end = start + bytes; 3835 3836 // Find the regions of the allocated chunk that can be promoted to large pages. 3837 char* lp_start = align_up(start, large_page_size); 3838 char* lp_end = align_down(end, large_page_size); 3839 3840 size_t lp_bytes = lp_end - lp_start; 3841 3842 assert(is_aligned(lp_bytes, large_page_size), "Must be"); 3843 3844 if (lp_bytes == 0) { 3845 // The mapped region doesn't even span the start and the end of a large page. 3846 // Fall back to allocate a non-special area. 3847 ::munmap(start, end - start); 3848 return NULL; 3849 } 3850 3851 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3852 3853 void* result; 3854 3855 // Commit small-paged leading area. 3856 if (start != lp_start) { 3857 result = ::mmap(start, lp_start - start, prot, 3858 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3859 -1, 0); 3860 if (result == MAP_FAILED) { 3861 ::munmap(lp_start, end - lp_start); 3862 return NULL; 3863 } 3864 } 3865 3866 // Commit large-paged area. 3867 result = ::mmap(lp_start, lp_bytes, prot, 3868 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB, 3869 -1, 0); 3870 if (result == MAP_FAILED) { 3871 warn_on_large_pages_failure(lp_start, lp_bytes, errno); 3872 // If the mmap above fails, the large pages region will be unmapped and we 3873 // have regions before and after with small pages. Release these regions. 3874 // 3875 // | mapped | unmapped | mapped | 3876 // ^ ^ ^ ^ 3877 // start lp_start lp_end end 3878 // 3879 ::munmap(start, lp_start - start); 3880 ::munmap(lp_end, end - lp_end); 3881 return NULL; 3882 } 3883 3884 // Commit small-paged trailing area. 3885 if (lp_end != end) { 3886 result = ::mmap(lp_end, end - lp_end, prot, 3887 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3888 -1, 0); 3889 if (result == MAP_FAILED) { 3890 ::munmap(start, lp_end - start); 3891 return NULL; 3892 } 3893 } 3894 3895 return start; 3896 } 3897 3898 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes, 3899 size_t alignment, 3900 char* req_addr, 3901 bool exec) { 3902 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3903 assert(is_aligned(req_addr, alignment), "Must be"); 3904 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be"); 3905 assert(is_power_of_2(os::large_page_size()), "Must be"); 3906 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes"); 3907 3908 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) { 3909 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec); 3910 } else { 3911 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec); 3912 } 3913 } 3914 3915 char* os::reserve_memory_special(size_t bytes, size_t alignment, 3916 char* req_addr, bool exec) { 3917 assert(UseLargePages, "only for large pages"); 3918 3919 char* addr; 3920 if (UseSHM) { 3921 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec); 3922 } else { 3923 assert(UseHugeTLBFS, "must be"); 3924 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec); 3925 } 3926 3927 if (addr != NULL) { 3928 if (UseNUMAInterleaving) { 3929 numa_make_global(addr, bytes); 3930 } 3931 3932 // The memory is committed 3933 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 3934 } 3935 3936 return addr; 3937 } 3938 3939 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) { 3940 // detaching the SHM segment will also delete it, see reserve_memory_special_shm() 3941 return shmdt(base) == 0; 3942 } 3943 3944 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) { 3945 return pd_release_memory(base, bytes); 3946 } 3947 3948 bool os::release_memory_special(char* base, size_t bytes) { 3949 bool res; 3950 if (MemTracker::tracking_level() > NMT_minimal) { 3951 Tracker tkr(Tracker::release); 3952 res = os::Linux::release_memory_special_impl(base, bytes); 3953 if (res) { 3954 tkr.record((address)base, bytes); 3955 } 3956 3957 } else { 3958 res = os::Linux::release_memory_special_impl(base, bytes); 3959 } 3960 return res; 3961 } 3962 3963 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) { 3964 assert(UseLargePages, "only for large pages"); 3965 bool res; 3966 3967 if (UseSHM) { 3968 res = os::Linux::release_memory_special_shm(base, bytes); 3969 } else { 3970 assert(UseHugeTLBFS, "must be"); 3971 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes); 3972 } 3973 return res; 3974 } 3975 3976 size_t os::large_page_size() { 3977 return _large_page_size; 3978 } 3979 3980 // With SysV SHM the entire memory region must be allocated as shared 3981 // memory. 3982 // HugeTLBFS allows application to commit large page memory on demand. 3983 // However, when committing memory with HugeTLBFS fails, the region 3984 // that was supposed to be committed will lose the old reservation 3985 // and allow other threads to steal that memory region. Because of this 3986 // behavior we can't commit HugeTLBFS memory. 3987 bool os::can_commit_large_page_memory() { 3988 return UseTransparentHugePages; 3989 } 3990 3991 bool os::can_execute_large_page_memory() { 3992 return UseTransparentHugePages || UseHugeTLBFS; 3993 } 3994 3995 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) { 3996 assert(file_desc >= 0, "file_desc is not valid"); 3997 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr); 3998 if (result != NULL) { 3999 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) { 4000 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory")); 4001 } 4002 } 4003 return result; 4004 } 4005 4006 // Reserve memory at an arbitrary address, only if that area is 4007 // available (and not reserved for something else). 4008 4009 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 4010 const int max_tries = 10; 4011 char* base[max_tries]; 4012 size_t size[max_tries]; 4013 const size_t gap = 0x000000; 4014 4015 // Assert only that the size is a multiple of the page size, since 4016 // that's all that mmap requires, and since that's all we really know 4017 // about at this low abstraction level. If we need higher alignment, 4018 // we can either pass an alignment to this method or verify alignment 4019 // in one of the methods further up the call chain. See bug 5044738. 4020 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 4021 4022 // Repeatedly allocate blocks until the block is allocated at the 4023 // right spot. 4024 4025 // Linux mmap allows caller to pass an address as hint; give it a try first, 4026 // if kernel honors the hint then we can return immediately. 4027 char * addr = anon_mmap(requested_addr, bytes, false); 4028 if (addr == requested_addr) { 4029 return requested_addr; 4030 } 4031 4032 if (addr != NULL) { 4033 // mmap() is successful but it fails to reserve at the requested address 4034 anon_munmap(addr, bytes); 4035 } 4036 4037 int i; 4038 for (i = 0; i < max_tries; ++i) { 4039 base[i] = reserve_memory(bytes); 4040 4041 if (base[i] != NULL) { 4042 // Is this the block we wanted? 4043 if (base[i] == requested_addr) { 4044 size[i] = bytes; 4045 break; 4046 } 4047 4048 // Does this overlap the block we wanted? Give back the overlapped 4049 // parts and try again. 4050 4051 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i]; 4052 if (top_overlap >= 0 && (size_t)top_overlap < bytes) { 4053 unmap_memory(base[i], top_overlap); 4054 base[i] += top_overlap; 4055 size[i] = bytes - top_overlap; 4056 } else { 4057 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr; 4058 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) { 4059 unmap_memory(requested_addr, bottom_overlap); 4060 size[i] = bytes - bottom_overlap; 4061 } else { 4062 size[i] = bytes; 4063 } 4064 } 4065 } 4066 } 4067 4068 // Give back the unused reserved pieces. 4069 4070 for (int j = 0; j < i; ++j) { 4071 if (base[j] != NULL) { 4072 unmap_memory(base[j], size[j]); 4073 } 4074 } 4075 4076 if (i < max_tries) { 4077 return requested_addr; 4078 } else { 4079 return NULL; 4080 } 4081 } 4082 4083 size_t os::read(int fd, void *buf, unsigned int nBytes) { 4084 return ::read(fd, buf, nBytes); 4085 } 4086 4087 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 4088 return ::pread(fd, buf, nBytes, offset); 4089 } 4090 4091 // Short sleep, direct OS call. 4092 // 4093 // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee 4094 // sched_yield(2) will actually give up the CPU: 4095 // 4096 // * Alone on this pariticular CPU, keeps running. 4097 // * Before the introduction of "skip_buddy" with "compat_yield" disabled 4098 // (pre 2.6.39). 4099 // 4100 // So calling this with 0 is an alternative. 4101 // 4102 void os::naked_short_sleep(jlong ms) { 4103 struct timespec req; 4104 4105 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 4106 req.tv_sec = 0; 4107 if (ms > 0) { 4108 req.tv_nsec = (ms % 1000) * 1000000; 4109 } else { 4110 req.tv_nsec = 1; 4111 } 4112 4113 nanosleep(&req, NULL); 4114 4115 return; 4116 } 4117 4118 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 4119 void os::infinite_sleep() { 4120 while (true) { // sleep forever ... 4121 ::sleep(100); // ... 100 seconds at a time 4122 } 4123 } 4124 4125 // Used to convert frequent JVM_Yield() to nops 4126 bool os::dont_yield() { 4127 return DontYieldALot; 4128 } 4129 4130 void os::naked_yield() { 4131 sched_yield(); 4132 } 4133 4134 //////////////////////////////////////////////////////////////////////////////// 4135 // thread priority support 4136 4137 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER 4138 // only supports dynamic priority, static priority must be zero. For real-time 4139 // applications, Linux supports SCHED_RR which allows static priority (1-99). 4140 // However, for large multi-threaded applications, SCHED_RR is not only slower 4141 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 4142 // of 5 runs - Sep 2005). 4143 // 4144 // The following code actually changes the niceness of kernel-thread/LWP. It 4145 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 4146 // not the entire user process, and user level threads are 1:1 mapped to kernel 4147 // threads. It has always been the case, but could change in the future. For 4148 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 4149 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 4150 4151 int os::java_to_os_priority[CriticalPriority + 1] = { 4152 19, // 0 Entry should never be used 4153 4154 4, // 1 MinPriority 4155 3, // 2 4156 2, // 3 4157 4158 1, // 4 4159 0, // 5 NormPriority 4160 -1, // 6 4161 4162 -2, // 7 4163 -3, // 8 4164 -4, // 9 NearMaxPriority 4165 4166 -5, // 10 MaxPriority 4167 4168 -5 // 11 CriticalPriority 4169 }; 4170 4171 static int prio_init() { 4172 if (ThreadPriorityPolicy == 1) { 4173 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 4174 // if effective uid is not root. Perhaps, a more elegant way of doing 4175 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 4176 if (geteuid() != 0) { 4177 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 4178 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux"); 4179 } 4180 ThreadPriorityPolicy = 0; 4181 } 4182 } 4183 if (UseCriticalJavaThreadPriority) { 4184 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 4185 } 4186 return 0; 4187 } 4188 4189 OSReturn os::set_native_priority(Thread* thread, int newpri) { 4190 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 4191 4192 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 4193 return (ret == 0) ? OS_OK : OS_ERR; 4194 } 4195 4196 OSReturn os::get_native_priority(const Thread* const thread, 4197 int *priority_ptr) { 4198 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 4199 *priority_ptr = java_to_os_priority[NormPriority]; 4200 return OS_OK; 4201 } 4202 4203 errno = 0; 4204 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 4205 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 4206 } 4207 4208 // Hint to the underlying OS that a task switch would not be good. 4209 // Void return because it's a hint and can fail. 4210 void os::hint_no_preempt() {} 4211 4212 //////////////////////////////////////////////////////////////////////////////// 4213 // suspend/resume support 4214 4215 // The low-level signal-based suspend/resume support is a remnant from the 4216 // old VM-suspension that used to be for java-suspension, safepoints etc, 4217 // within hotspot. Currently used by JFR's OSThreadSampler 4218 // 4219 // The remaining code is greatly simplified from the more general suspension 4220 // code that used to be used. 4221 // 4222 // The protocol is quite simple: 4223 // - suspend: 4224 // - sends a signal to the target thread 4225 // - polls the suspend state of the osthread using a yield loop 4226 // - target thread signal handler (SR_handler) sets suspend state 4227 // and blocks in sigsuspend until continued 4228 // - resume: 4229 // - sets target osthread state to continue 4230 // - sends signal to end the sigsuspend loop in the SR_handler 4231 // 4232 // Note that the SR_lock plays no role in this suspend/resume protocol, 4233 // but is checked for NULL in SR_handler as a thread termination indicator. 4234 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs. 4235 // 4236 // Note that resume_clear_context() and suspend_save_context() are needed 4237 // by SR_handler(), so that fetch_frame_from_ucontext() works, 4238 // which in part is used by: 4239 // - Forte Analyzer: AsyncGetCallTrace() 4240 // - StackBanging: get_frame_at_stack_banging_point() 4241 4242 static void resume_clear_context(OSThread *osthread) { 4243 osthread->set_ucontext(NULL); 4244 osthread->set_siginfo(NULL); 4245 } 4246 4247 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, 4248 ucontext_t* context) { 4249 osthread->set_ucontext(context); 4250 osthread->set_siginfo(siginfo); 4251 } 4252 4253 // Handler function invoked when a thread's execution is suspended or 4254 // resumed. We have to be careful that only async-safe functions are 4255 // called here (Note: most pthread functions are not async safe and 4256 // should be avoided.) 4257 // 4258 // Note: sigwait() is a more natural fit than sigsuspend() from an 4259 // interface point of view, but sigwait() prevents the signal hander 4260 // from being run. libpthread would get very confused by not having 4261 // its signal handlers run and prevents sigwait()'s use with the 4262 // mutex granting granting signal. 4263 // 4264 // Currently only ever called on the VMThread and JavaThreads (PC sampling) 4265 // 4266 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 4267 // Save and restore errno to avoid confusing native code with EINTR 4268 // after sigsuspend. 4269 int old_errno = errno; 4270 4271 Thread* thread = Thread::current_or_null_safe(); 4272 assert(thread != NULL, "Missing current thread in SR_handler"); 4273 4274 // On some systems we have seen signal delivery get "stuck" until the signal 4275 // mask is changed as part of thread termination. Check that the current thread 4276 // has not already terminated (via SR_lock()) - else the following assertion 4277 // will fail because the thread is no longer a JavaThread as the ~JavaThread 4278 // destructor has completed. 4279 4280 if (thread->SR_lock() == NULL) { 4281 return; 4282 } 4283 4284 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 4285 4286 OSThread* osthread = thread->osthread(); 4287 4288 os::SuspendResume::State current = osthread->sr.state(); 4289 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 4290 suspend_save_context(osthread, siginfo, context); 4291 4292 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 4293 os::SuspendResume::State state = osthread->sr.suspended(); 4294 if (state == os::SuspendResume::SR_SUSPENDED) { 4295 sigset_t suspend_set; // signals for sigsuspend() 4296 sigemptyset(&suspend_set); 4297 // get current set of blocked signals and unblock resume signal 4298 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 4299 sigdelset(&suspend_set, SR_signum); 4300 4301 sr_semaphore.signal(); 4302 // wait here until we are resumed 4303 while (1) { 4304 sigsuspend(&suspend_set); 4305 4306 os::SuspendResume::State result = osthread->sr.running(); 4307 if (result == os::SuspendResume::SR_RUNNING) { 4308 sr_semaphore.signal(); 4309 break; 4310 } 4311 } 4312 4313 } else if (state == os::SuspendResume::SR_RUNNING) { 4314 // request was cancelled, continue 4315 } else { 4316 ShouldNotReachHere(); 4317 } 4318 4319 resume_clear_context(osthread); 4320 } else if (current == os::SuspendResume::SR_RUNNING) { 4321 // request was cancelled, continue 4322 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 4323 // ignore 4324 } else { 4325 // ignore 4326 } 4327 4328 errno = old_errno; 4329 } 4330 4331 static int SR_initialize() { 4332 struct sigaction act; 4333 char *s; 4334 4335 // Get signal number to use for suspend/resume 4336 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 4337 int sig = ::strtol(s, 0, 10); 4338 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769. 4339 sig < NSIG) { // Must be legal signal and fit into sigflags[]. 4340 SR_signum = sig; 4341 } else { 4342 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.", 4343 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum); 4344 } 4345 } 4346 4347 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 4348 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 4349 4350 sigemptyset(&SR_sigset); 4351 sigaddset(&SR_sigset, SR_signum); 4352 4353 // Set up signal handler for suspend/resume 4354 act.sa_flags = SA_RESTART|SA_SIGINFO; 4355 act.sa_handler = (void (*)(int)) SR_handler; 4356 4357 // SR_signum is blocked by default. 4358 // 4528190 - We also need to block pthread restart signal (32 on all 4359 // supported Linux platforms). Note that LinuxThreads need to block 4360 // this signal for all threads to work properly. So we don't have 4361 // to use hard-coded signal number when setting up the mask. 4362 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 4363 4364 if (sigaction(SR_signum, &act, 0) == -1) { 4365 return -1; 4366 } 4367 4368 // Save signal flag 4369 os::Linux::set_our_sigflags(SR_signum, act.sa_flags); 4370 return 0; 4371 } 4372 4373 static int sr_notify(OSThread* osthread) { 4374 int status = pthread_kill(osthread->pthread_id(), SR_signum); 4375 assert_status(status == 0, status, "pthread_kill"); 4376 return status; 4377 } 4378 4379 // "Randomly" selected value for how long we want to spin 4380 // before bailing out on suspending a thread, also how often 4381 // we send a signal to a thread we want to resume 4382 static const int RANDOMLY_LARGE_INTEGER = 1000000; 4383 static const int RANDOMLY_LARGE_INTEGER2 = 100; 4384 4385 // returns true on success and false on error - really an error is fatal 4386 // but this seems the normal response to library errors 4387 static bool do_suspend(OSThread* osthread) { 4388 assert(osthread->sr.is_running(), "thread should be running"); 4389 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 4390 4391 // mark as suspended and send signal 4392 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 4393 // failed to switch, state wasn't running? 4394 ShouldNotReachHere(); 4395 return false; 4396 } 4397 4398 if (sr_notify(osthread) != 0) { 4399 ShouldNotReachHere(); 4400 } 4401 4402 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 4403 while (true) { 4404 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { 4405 break; 4406 } else { 4407 // timeout 4408 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 4409 if (cancelled == os::SuspendResume::SR_RUNNING) { 4410 return false; 4411 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 4412 // make sure that we consume the signal on the semaphore as well 4413 sr_semaphore.wait(); 4414 break; 4415 } else { 4416 ShouldNotReachHere(); 4417 return false; 4418 } 4419 } 4420 } 4421 4422 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 4423 return true; 4424 } 4425 4426 static void do_resume(OSThread* osthread) { 4427 assert(osthread->sr.is_suspended(), "thread should be suspended"); 4428 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 4429 4430 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 4431 // failed to switch to WAKEUP_REQUEST 4432 ShouldNotReachHere(); 4433 return; 4434 } 4435 4436 while (true) { 4437 if (sr_notify(osthread) == 0) { 4438 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { 4439 if (osthread->sr.is_running()) { 4440 return; 4441 } 4442 } 4443 } else { 4444 ShouldNotReachHere(); 4445 } 4446 } 4447 4448 guarantee(osthread->sr.is_running(), "Must be running!"); 4449 } 4450 4451 /////////////////////////////////////////////////////////////////////////////////// 4452 // signal handling (except suspend/resume) 4453 4454 // This routine may be used by user applications as a "hook" to catch signals. 4455 // The user-defined signal handler must pass unrecognized signals to this 4456 // routine, and if it returns true (non-zero), then the signal handler must 4457 // return immediately. If the flag "abort_if_unrecognized" is true, then this 4458 // routine will never retun false (zero), but instead will execute a VM panic 4459 // routine kill the process. 4460 // 4461 // If this routine returns false, it is OK to call it again. This allows 4462 // the user-defined signal handler to perform checks either before or after 4463 // the VM performs its own checks. Naturally, the user code would be making 4464 // a serious error if it tried to handle an exception (such as a null check 4465 // or breakpoint) that the VM was generating for its own correct operation. 4466 // 4467 // This routine may recognize any of the following kinds of signals: 4468 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 4469 // It should be consulted by handlers for any of those signals. 4470 // 4471 // The caller of this routine must pass in the three arguments supplied 4472 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 4473 // field of the structure passed to sigaction(). This routine assumes that 4474 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 4475 // 4476 // Note that the VM will print warnings if it detects conflicting signal 4477 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 4478 // 4479 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo, 4480 siginfo_t* siginfo, 4481 void* ucontext, 4482 int abort_if_unrecognized); 4483 4484 static void signalHandler(int sig, siginfo_t* info, void* uc) { 4485 assert(info != NULL && uc != NULL, "it must be old kernel"); 4486 int orig_errno = errno; // Preserve errno value over signal handler. 4487 JVM_handle_linux_signal(sig, info, uc, true); 4488 errno = orig_errno; 4489 } 4490 4491 4492 // This boolean allows users to forward their own non-matching signals 4493 // to JVM_handle_linux_signal, harmlessly. 4494 bool os::Linux::signal_handlers_are_installed = false; 4495 4496 // For signal-chaining 4497 struct sigaction sigact[NSIG]; 4498 uint64_t sigs = 0; 4499 #if (64 < NSIG-1) 4500 #error "Not all signals can be encoded in sigs. Adapt its type!" 4501 #endif 4502 bool os::Linux::libjsig_is_loaded = false; 4503 typedef struct sigaction *(*get_signal_t)(int); 4504 get_signal_t os::Linux::get_signal_action = NULL; 4505 4506 struct sigaction* os::Linux::get_chained_signal_action(int sig) { 4507 struct sigaction *actp = NULL; 4508 4509 if (libjsig_is_loaded) { 4510 // Retrieve the old signal handler from libjsig 4511 actp = (*get_signal_action)(sig); 4512 } 4513 if (actp == NULL) { 4514 // Retrieve the preinstalled signal handler from jvm 4515 actp = get_preinstalled_handler(sig); 4516 } 4517 4518 return actp; 4519 } 4520 4521 static bool call_chained_handler(struct sigaction *actp, int sig, 4522 siginfo_t *siginfo, void *context) { 4523 // Call the old signal handler 4524 if (actp->sa_handler == SIG_DFL) { 4525 // It's more reasonable to let jvm treat it as an unexpected exception 4526 // instead of taking the default action. 4527 return false; 4528 } else if (actp->sa_handler != SIG_IGN) { 4529 if ((actp->sa_flags & SA_NODEFER) == 0) { 4530 // automaticlly block the signal 4531 sigaddset(&(actp->sa_mask), sig); 4532 } 4533 4534 sa_handler_t hand = NULL; 4535 sa_sigaction_t sa = NULL; 4536 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 4537 // retrieve the chained handler 4538 if (siginfo_flag_set) { 4539 sa = actp->sa_sigaction; 4540 } else { 4541 hand = actp->sa_handler; 4542 } 4543 4544 if ((actp->sa_flags & SA_RESETHAND) != 0) { 4545 actp->sa_handler = SIG_DFL; 4546 } 4547 4548 // try to honor the signal mask 4549 sigset_t oset; 4550 sigemptyset(&oset); 4551 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 4552 4553 // call into the chained handler 4554 if (siginfo_flag_set) { 4555 (*sa)(sig, siginfo, context); 4556 } else { 4557 (*hand)(sig); 4558 } 4559 4560 // restore the signal mask 4561 pthread_sigmask(SIG_SETMASK, &oset, NULL); 4562 } 4563 // Tell jvm's signal handler the signal is taken care of. 4564 return true; 4565 } 4566 4567 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) { 4568 bool chained = false; 4569 // signal-chaining 4570 if (UseSignalChaining) { 4571 struct sigaction *actp = get_chained_signal_action(sig); 4572 if (actp != NULL) { 4573 chained = call_chained_handler(actp, sig, siginfo, context); 4574 } 4575 } 4576 return chained; 4577 } 4578 4579 struct sigaction* os::Linux::get_preinstalled_handler(int sig) { 4580 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) { 4581 return &sigact[sig]; 4582 } 4583 return NULL; 4584 } 4585 4586 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 4587 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4588 sigact[sig] = oldAct; 4589 sigs |= (uint64_t)1 << (sig-1); 4590 } 4591 4592 // for diagnostic 4593 int sigflags[NSIG]; 4594 4595 int os::Linux::get_our_sigflags(int sig) { 4596 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4597 return sigflags[sig]; 4598 } 4599 4600 void os::Linux::set_our_sigflags(int sig, int flags) { 4601 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4602 if (sig > 0 && sig < NSIG) { 4603 sigflags[sig] = flags; 4604 } 4605 } 4606 4607 void os::Linux::set_signal_handler(int sig, bool set_installed) { 4608 // Check for overwrite. 4609 struct sigaction oldAct; 4610 sigaction(sig, (struct sigaction*)NULL, &oldAct); 4611 4612 void* oldhand = oldAct.sa_sigaction 4613 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4614 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4615 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 4616 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 4617 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 4618 if (AllowUserSignalHandlers || !set_installed) { 4619 // Do not overwrite; user takes responsibility to forward to us. 4620 return; 4621 } else if (UseSignalChaining) { 4622 // save the old handler in jvm 4623 save_preinstalled_handler(sig, oldAct); 4624 // libjsig also interposes the sigaction() call below and saves the 4625 // old sigaction on it own. 4626 } else { 4627 fatal("Encountered unexpected pre-existing sigaction handler " 4628 "%#lx for signal %d.", (long)oldhand, sig); 4629 } 4630 } 4631 4632 struct sigaction sigAct; 4633 sigfillset(&(sigAct.sa_mask)); 4634 sigAct.sa_handler = SIG_DFL; 4635 if (!set_installed) { 4636 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4637 } else { 4638 sigAct.sa_sigaction = signalHandler; 4639 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4640 } 4641 // Save flags, which are set by ours 4642 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4643 sigflags[sig] = sigAct.sa_flags; 4644 4645 int ret = sigaction(sig, &sigAct, &oldAct); 4646 assert(ret == 0, "check"); 4647 4648 void* oldhand2 = oldAct.sa_sigaction 4649 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4650 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4651 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 4652 } 4653 4654 // install signal handlers for signals that HotSpot needs to 4655 // handle in order to support Java-level exception handling. 4656 4657 void os::Linux::install_signal_handlers() { 4658 if (!signal_handlers_are_installed) { 4659 signal_handlers_are_installed = true; 4660 4661 // signal-chaining 4662 typedef void (*signal_setting_t)(); 4663 signal_setting_t begin_signal_setting = NULL; 4664 signal_setting_t end_signal_setting = NULL; 4665 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4666 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 4667 if (begin_signal_setting != NULL) { 4668 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4669 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 4670 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 4671 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 4672 libjsig_is_loaded = true; 4673 assert(UseSignalChaining, "should enable signal-chaining"); 4674 } 4675 if (libjsig_is_loaded) { 4676 // Tell libjsig jvm is setting signal handlers 4677 (*begin_signal_setting)(); 4678 } 4679 4680 set_signal_handler(SIGSEGV, true); 4681 set_signal_handler(SIGPIPE, true); 4682 set_signal_handler(SIGBUS, true); 4683 set_signal_handler(SIGILL, true); 4684 set_signal_handler(SIGFPE, true); 4685 #if defined(PPC64) 4686 set_signal_handler(SIGTRAP, true); 4687 #endif 4688 set_signal_handler(SIGXFSZ, true); 4689 4690 if (libjsig_is_loaded) { 4691 // Tell libjsig jvm finishes setting signal handlers 4692 (*end_signal_setting)(); 4693 } 4694 4695 // We don't activate signal checker if libjsig is in place, we trust ourselves 4696 // and if UserSignalHandler is installed all bets are off. 4697 // Log that signal checking is off only if -verbose:jni is specified. 4698 if (CheckJNICalls) { 4699 if (libjsig_is_loaded) { 4700 if (PrintJNIResolving) { 4701 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 4702 } 4703 check_signals = false; 4704 } 4705 if (AllowUserSignalHandlers) { 4706 if (PrintJNIResolving) { 4707 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 4708 } 4709 check_signals = false; 4710 } 4711 } 4712 } 4713 } 4714 4715 // This is the fastest way to get thread cpu time on Linux. 4716 // Returns cpu time (user+sys) for any thread, not only for current. 4717 // POSIX compliant clocks are implemented in the kernels 2.6.16+. 4718 // It might work on 2.6.10+ with a special kernel/glibc patch. 4719 // For reference, please, see IEEE Std 1003.1-2004: 4720 // http://www.unix.org/single_unix_specification 4721 4722 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) { 4723 struct timespec tp; 4724 int rc = os::Linux::clock_gettime(clockid, &tp); 4725 assert(rc == 0, "clock_gettime is expected to return 0 code"); 4726 4727 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec; 4728 } 4729 4730 void os::Linux::initialize_os_info() { 4731 assert(_os_version == 0, "OS info already initialized"); 4732 4733 struct utsname _uname; 4734 4735 uint32_t major; 4736 uint32_t minor; 4737 uint32_t fix; 4738 4739 int rc; 4740 4741 // Kernel version is unknown if 4742 // verification below fails. 4743 _os_version = 0x01000000; 4744 4745 rc = uname(&_uname); 4746 if (rc != -1) { 4747 4748 rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix); 4749 if (rc == 3) { 4750 4751 if (major < 256 && minor < 256 && fix < 256) { 4752 // Kernel version format is as expected, 4753 // set it overriding unknown state. 4754 _os_version = (major << 16) | 4755 (minor << 8 ) | 4756 (fix << 0 ) ; 4757 } 4758 } 4759 } 4760 } 4761 4762 uint32_t os::Linux::os_version() { 4763 assert(_os_version != 0, "not initialized"); 4764 return _os_version & 0x00FFFFFF; 4765 } 4766 4767 bool os::Linux::os_version_is_known() { 4768 assert(_os_version != 0, "not initialized"); 4769 return _os_version & 0x01000000 ? false : true; 4770 } 4771 4772 ///// 4773 // glibc on Linux platform uses non-documented flag 4774 // to indicate, that some special sort of signal 4775 // trampoline is used. 4776 // We will never set this flag, and we should 4777 // ignore this flag in our diagnostic 4778 #ifdef SIGNIFICANT_SIGNAL_MASK 4779 #undef SIGNIFICANT_SIGNAL_MASK 4780 #endif 4781 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 4782 4783 static const char* get_signal_handler_name(address handler, 4784 char* buf, int buflen) { 4785 int offset = 0; 4786 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 4787 if (found) { 4788 // skip directory names 4789 const char *p1, *p2; 4790 p1 = buf; 4791 size_t len = strlen(os::file_separator()); 4792 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 4793 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 4794 } else { 4795 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 4796 } 4797 return buf; 4798 } 4799 4800 static void print_signal_handler(outputStream* st, int sig, 4801 char* buf, size_t buflen) { 4802 struct sigaction sa; 4803 4804 sigaction(sig, NULL, &sa); 4805 4806 // See comment for SIGNIFICANT_SIGNAL_MASK define 4807 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4808 4809 st->print("%s: ", os::exception_name(sig, buf, buflen)); 4810 4811 address handler = (sa.sa_flags & SA_SIGINFO) 4812 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 4813 : CAST_FROM_FN_PTR(address, sa.sa_handler); 4814 4815 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 4816 st->print("SIG_DFL"); 4817 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 4818 st->print("SIG_IGN"); 4819 } else { 4820 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 4821 } 4822 4823 st->print(", sa_mask[0]="); 4824 os::Posix::print_signal_set_short(st, &sa.sa_mask); 4825 4826 address rh = VMError::get_resetted_sighandler(sig); 4827 // May be, handler was resetted by VMError? 4828 if (rh != NULL) { 4829 handler = rh; 4830 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 4831 } 4832 4833 st->print(", sa_flags="); 4834 os::Posix::print_sa_flags(st, sa.sa_flags); 4835 4836 // Check: is it our handler? 4837 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 4838 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 4839 // It is our signal handler 4840 // check for flags, reset system-used one! 4841 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) { 4842 st->print( 4843 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 4844 os::Linux::get_our_sigflags(sig)); 4845 } 4846 } 4847 st->cr(); 4848 } 4849 4850 4851 #define DO_SIGNAL_CHECK(sig) \ 4852 do { \ 4853 if (!sigismember(&check_signal_done, sig)) { \ 4854 os::Linux::check_signal_handler(sig); \ 4855 } \ 4856 } while (0) 4857 4858 // This method is a periodic task to check for misbehaving JNI applications 4859 // under CheckJNI, we can add any periodic checks here 4860 4861 void os::run_periodic_checks() { 4862 if (check_signals == false) return; 4863 4864 // SEGV and BUS if overridden could potentially prevent 4865 // generation of hs*.log in the event of a crash, debugging 4866 // such a case can be very challenging, so we absolutely 4867 // check the following for a good measure: 4868 DO_SIGNAL_CHECK(SIGSEGV); 4869 DO_SIGNAL_CHECK(SIGILL); 4870 DO_SIGNAL_CHECK(SIGFPE); 4871 DO_SIGNAL_CHECK(SIGBUS); 4872 DO_SIGNAL_CHECK(SIGPIPE); 4873 DO_SIGNAL_CHECK(SIGXFSZ); 4874 #if defined(PPC64) 4875 DO_SIGNAL_CHECK(SIGTRAP); 4876 #endif 4877 4878 // ReduceSignalUsage allows the user to override these handlers 4879 // see comments at the very top and jvm_md.h 4880 if (!ReduceSignalUsage) { 4881 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 4882 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 4883 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 4884 DO_SIGNAL_CHECK(BREAK_SIGNAL); 4885 } 4886 4887 DO_SIGNAL_CHECK(SR_signum); 4888 } 4889 4890 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 4891 4892 static os_sigaction_t os_sigaction = NULL; 4893 4894 void os::Linux::check_signal_handler(int sig) { 4895 char buf[O_BUFLEN]; 4896 address jvmHandler = NULL; 4897 4898 4899 struct sigaction act; 4900 if (os_sigaction == NULL) { 4901 // only trust the default sigaction, in case it has been interposed 4902 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 4903 if (os_sigaction == NULL) return; 4904 } 4905 4906 os_sigaction(sig, (struct sigaction*)NULL, &act); 4907 4908 4909 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4910 4911 address thisHandler = (act.sa_flags & SA_SIGINFO) 4912 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 4913 : CAST_FROM_FN_PTR(address, act.sa_handler); 4914 4915 4916 switch (sig) { 4917 case SIGSEGV: 4918 case SIGBUS: 4919 case SIGFPE: 4920 case SIGPIPE: 4921 case SIGILL: 4922 case SIGXFSZ: 4923 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 4924 break; 4925 4926 case SHUTDOWN1_SIGNAL: 4927 case SHUTDOWN2_SIGNAL: 4928 case SHUTDOWN3_SIGNAL: 4929 case BREAK_SIGNAL: 4930 jvmHandler = (address)user_handler(); 4931 break; 4932 4933 default: 4934 if (sig == SR_signum) { 4935 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 4936 } else { 4937 return; 4938 } 4939 break; 4940 } 4941 4942 if (thisHandler != jvmHandler) { 4943 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 4944 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 4945 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 4946 // No need to check this sig any longer 4947 sigaddset(&check_signal_done, sig); 4948 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 4949 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 4950 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 4951 exception_name(sig, buf, O_BUFLEN)); 4952 } 4953 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) { 4954 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 4955 tty->print("expected:"); 4956 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig)); 4957 tty->cr(); 4958 tty->print(" found:"); 4959 os::Posix::print_sa_flags(tty, act.sa_flags); 4960 tty->cr(); 4961 // No need to check this sig any longer 4962 sigaddset(&check_signal_done, sig); 4963 } 4964 4965 // Dump all the signal 4966 if (sigismember(&check_signal_done, sig)) { 4967 print_signal_handlers(tty, buf, O_BUFLEN); 4968 } 4969 } 4970 4971 extern void report_error(char* file_name, int line_no, char* title, 4972 char* format, ...); 4973 4974 // this is called _before_ most of the global arguments have been parsed 4975 void os::init(void) { 4976 char dummy; // used to get a guess on initial stack address 4977 4978 clock_tics_per_sec = sysconf(_SC_CLK_TCK); 4979 4980 init_random(1234567); 4981 4982 Linux::set_page_size(sysconf(_SC_PAGESIZE)); 4983 if (Linux::page_size() == -1) { 4984 fatal("os_linux.cpp: os::init: sysconf failed (%s)", 4985 os::strerror(errno)); 4986 } 4987 init_page_sizes((size_t) Linux::page_size()); 4988 4989 Linux::initialize_system_info(); 4990 4991 Linux::initialize_os_info(); 4992 4993 // _main_thread points to the thread that created/loaded the JVM. 4994 Linux::_main_thread = pthread_self(); 4995 4996 Linux::clock_init(); 4997 initial_time_count = javaTimeNanos(); 4998 4999 // retrieve entry point for pthread_setname_np 5000 Linux::_pthread_setname_np = 5001 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np"); 5002 5003 os::Posix::init(); 5004 } 5005 5006 // To install functions for atexit system call 5007 extern "C" { 5008 static void perfMemory_exit_helper() { 5009 perfMemory_exit(); 5010 } 5011 } 5012 5013 void os::pd_init_container_support() { 5014 OSContainer::init(); 5015 } 5016 5017 // this is called _after_ the global arguments have been parsed 5018 jint os::init_2(void) { 5019 5020 os::Posix::init_2(); 5021 5022 Linux::fast_thread_clock_init(); 5023 5024 // initialize suspend/resume support - must do this before signal_sets_init() 5025 if (SR_initialize() != 0) { 5026 perror("SR_initialize failed"); 5027 return JNI_ERR; 5028 } 5029 5030 Linux::signal_sets_init(); 5031 Linux::install_signal_handlers(); 5032 // Initialize data for jdk.internal.misc.Signal 5033 if (!ReduceSignalUsage) { 5034 jdk_misc_signal_init(); 5035 } 5036 5037 // Check and sets minimum stack sizes against command line options 5038 if (Posix::set_minimum_stack_sizes() == JNI_ERR) { 5039 return JNI_ERR; 5040 } 5041 5042 suppress_primordial_thread_resolution = Arguments::created_by_java_launcher(); 5043 if (!suppress_primordial_thread_resolution) { 5044 Linux::capture_initial_stack(JavaThread::stack_size_at_create()); 5045 } 5046 5047 #if defined(IA32) 5048 workaround_expand_exec_shield_cs_limit(); 5049 #endif 5050 5051 Linux::libpthread_init(); 5052 Linux::sched_getcpu_init(); 5053 log_info(os)("HotSpot is running with %s, %s", 5054 Linux::glibc_version(), Linux::libpthread_version()); 5055 5056 if (UseNUMA) { 5057 if (!Linux::libnuma_init()) { 5058 UseNUMA = false; 5059 } else { 5060 if ((Linux::numa_max_node() < 1) || Linux::isbound_to_single_node()) { 5061 // If there's only one node (they start from 0) or if the process 5062 // is bound explicitly to a single node using membind, disable NUMA. 5063 UseNUMA = false; 5064 } 5065 } 5066 5067 if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) { 5068 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way 5069 // we can make the adaptive lgrp chunk resizing work. If the user specified both 5070 // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn 5071 // and disable adaptive resizing. 5072 if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) { 5073 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, " 5074 "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)"); 5075 UseAdaptiveSizePolicy = false; 5076 UseAdaptiveNUMAChunkSizing = false; 5077 } 5078 } 5079 5080 if (!UseNUMA && ForceNUMA) { 5081 UseNUMA = true; 5082 } 5083 } 5084 5085 if (MaxFDLimit) { 5086 // set the number of file descriptors to max. print out error 5087 // if getrlimit/setrlimit fails but continue regardless. 5088 struct rlimit nbr_files; 5089 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 5090 if (status != 0) { 5091 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno)); 5092 } else { 5093 nbr_files.rlim_cur = nbr_files.rlim_max; 5094 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 5095 if (status != 0) { 5096 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno)); 5097 } 5098 } 5099 } 5100 5101 // Initialize lock used to serialize thread creation (see os::create_thread) 5102 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); 5103 5104 // at-exit methods are called in the reverse order of their registration. 5105 // atexit functions are called on return from main or as a result of a 5106 // call to exit(3C). There can be only 32 of these functions registered 5107 // and atexit() does not set errno. 5108 5109 if (PerfAllowAtExitRegistration) { 5110 // only register atexit functions if PerfAllowAtExitRegistration is set. 5111 // atexit functions can be delayed until process exit time, which 5112 // can be problematic for embedded VM situations. Embedded VMs should 5113 // call DestroyJavaVM() to assure that VM resources are released. 5114 5115 // note: perfMemory_exit_helper atexit function may be removed in 5116 // the future if the appropriate cleanup code can be added to the 5117 // VM_Exit VMOperation's doit method. 5118 if (atexit(perfMemory_exit_helper) != 0) { 5119 warning("os::init_2 atexit(perfMemory_exit_helper) failed"); 5120 } 5121 } 5122 5123 // initialize thread priority policy 5124 prio_init(); 5125 5126 if (!FLAG_IS_DEFAULT(AllocateHeapAt)) { 5127 set_coredump_filter(false /*largepages*/, true /*dax_shared*/); 5128 } 5129 return JNI_OK; 5130 } 5131 5132 // Mark the polling page as unreadable 5133 void os::make_polling_page_unreadable(void) { 5134 if (!guard_memory((char*)_polling_page, Linux::page_size())) { 5135 fatal("Could not disable polling page"); 5136 } 5137 } 5138 5139 // Mark the polling page as readable 5140 void os::make_polling_page_readable(void) { 5141 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) { 5142 fatal("Could not enable polling page"); 5143 } 5144 } 5145 5146 // older glibc versions don't have this macro (which expands to 5147 // an optimized bit-counting function) so we have to roll our own 5148 #ifndef CPU_COUNT 5149 5150 static int _cpu_count(const cpu_set_t* cpus) { 5151 int count = 0; 5152 // only look up to the number of configured processors 5153 for (int i = 0; i < os::processor_count(); i++) { 5154 if (CPU_ISSET(i, cpus)) { 5155 count++; 5156 } 5157 } 5158 return count; 5159 } 5160 5161 #define CPU_COUNT(cpus) _cpu_count(cpus) 5162 5163 #endif // CPU_COUNT 5164 5165 // Get the current number of available processors for this process. 5166 // This value can change at any time during a process's lifetime. 5167 // sched_getaffinity gives an accurate answer as it accounts for cpusets. 5168 // If it appears there may be more than 1024 processors then we do a 5169 // dynamic check - see 6515172 for details. 5170 // If anything goes wrong we fallback to returning the number of online 5171 // processors - which can be greater than the number available to the process. 5172 int os::Linux::active_processor_count() { 5173 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors 5174 cpu_set_t* cpus_p = &cpus; 5175 int cpus_size = sizeof(cpu_set_t); 5176 5177 int configured_cpus = os::processor_count(); // upper bound on available cpus 5178 int cpu_count = 0; 5179 5180 // old build platforms may not support dynamic cpu sets 5181 #ifdef CPU_ALLOC 5182 5183 // To enable easy testing of the dynamic path on different platforms we 5184 // introduce a diagnostic flag: UseCpuAllocPath 5185 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) { 5186 // kernel may use a mask bigger than cpu_set_t 5187 log_trace(os)("active_processor_count: using dynamic path %s" 5188 "- configured processors: %d", 5189 UseCpuAllocPath ? "(forced) " : "", 5190 configured_cpus); 5191 cpus_p = CPU_ALLOC(configured_cpus); 5192 if (cpus_p != NULL) { 5193 cpus_size = CPU_ALLOC_SIZE(configured_cpus); 5194 // zero it just to be safe 5195 CPU_ZERO_S(cpus_size, cpus_p); 5196 } 5197 else { 5198 // failed to allocate so fallback to online cpus 5199 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); 5200 log_trace(os)("active_processor_count: " 5201 "CPU_ALLOC failed (%s) - using " 5202 "online processor count: %d", 5203 os::strerror(errno), online_cpus); 5204 return online_cpus; 5205 } 5206 } 5207 else { 5208 log_trace(os)("active_processor_count: using static path - configured processors: %d", 5209 configured_cpus); 5210 } 5211 #else // CPU_ALLOC 5212 // these stubs won't be executed 5213 #define CPU_COUNT_S(size, cpus) -1 5214 #define CPU_FREE(cpus) 5215 5216 log_trace(os)("active_processor_count: only static path available - configured processors: %d", 5217 configured_cpus); 5218 #endif // CPU_ALLOC 5219 5220 // pid 0 means the current thread - which we have to assume represents the process 5221 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) { 5222 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5223 cpu_count = CPU_COUNT_S(cpus_size, cpus_p); 5224 } 5225 else { 5226 cpu_count = CPU_COUNT(cpus_p); 5227 } 5228 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count); 5229 } 5230 else { 5231 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN); 5232 warning("sched_getaffinity failed (%s)- using online processor count (%d) " 5233 "which may exceed available processors", os::strerror(errno), cpu_count); 5234 } 5235 5236 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5237 CPU_FREE(cpus_p); 5238 } 5239 5240 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check"); 5241 return cpu_count; 5242 } 5243 5244 // Determine the active processor count from one of 5245 // three different sources: 5246 // 5247 // 1. User option -XX:ActiveProcessorCount 5248 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN) 5249 // 3. extracted from cgroup cpu subsystem (shares and quotas) 5250 // 5251 // Option 1, if specified, will always override. 5252 // If the cgroup subsystem is active and configured, we 5253 // will return the min of the cgroup and option 2 results. 5254 // This is required since tools, such as numactl, that 5255 // alter cpu affinity do not update cgroup subsystem 5256 // cpuset configuration files. 5257 int os::active_processor_count() { 5258 // User has overridden the number of active processors 5259 if (ActiveProcessorCount > 0) { 5260 log_trace(os)("active_processor_count: " 5261 "active processor count set by user : %d", 5262 ActiveProcessorCount); 5263 return ActiveProcessorCount; 5264 } 5265 5266 int active_cpus; 5267 if (OSContainer::is_containerized()) { 5268 active_cpus = OSContainer::active_processor_count(); 5269 log_trace(os)("active_processor_count: determined by OSContainer: %d", 5270 active_cpus); 5271 } else { 5272 active_cpus = os::Linux::active_processor_count(); 5273 } 5274 5275 return active_cpus; 5276 } 5277 5278 uint os::processor_id() { 5279 const int id = Linux::sched_getcpu(); 5280 assert(id >= 0 && id < _processor_count, "Invalid processor id"); 5281 return (uint)id; 5282 } 5283 5284 void os::set_native_thread_name(const char *name) { 5285 if (Linux::_pthread_setname_np) { 5286 char buf [16]; // according to glibc manpage, 16 chars incl. '/0' 5287 snprintf(buf, sizeof(buf), "%s", name); 5288 buf[sizeof(buf) - 1] = '\0'; 5289 const int rc = Linux::_pthread_setname_np(pthread_self(), buf); 5290 // ERANGE should not happen; all other errors should just be ignored. 5291 assert(rc != ERANGE, "pthread_setname_np failed"); 5292 } 5293 } 5294 5295 bool os::distribute_processes(uint length, uint* distribution) { 5296 // Not yet implemented. 5297 return false; 5298 } 5299 5300 bool os::bind_to_processor(uint processor_id) { 5301 // Not yet implemented. 5302 return false; 5303 } 5304 5305 /// 5306 5307 void os::SuspendedThreadTask::internal_do_task() { 5308 if (do_suspend(_thread->osthread())) { 5309 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 5310 do_task(context); 5311 do_resume(_thread->osthread()); 5312 } 5313 } 5314 5315 //////////////////////////////////////////////////////////////////////////////// 5316 // debug support 5317 5318 bool os::find(address addr, outputStream* st) { 5319 Dl_info dlinfo; 5320 memset(&dlinfo, 0, sizeof(dlinfo)); 5321 if (dladdr(addr, &dlinfo) != 0) { 5322 st->print(PTR_FORMAT ": ", p2i(addr)); 5323 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 5324 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname, 5325 p2i(addr) - p2i(dlinfo.dli_saddr)); 5326 } else if (dlinfo.dli_fbase != NULL) { 5327 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase)); 5328 } else { 5329 st->print("<absolute address>"); 5330 } 5331 if (dlinfo.dli_fname != NULL) { 5332 st->print(" in %s", dlinfo.dli_fname); 5333 } 5334 if (dlinfo.dli_fbase != NULL) { 5335 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase)); 5336 } 5337 st->cr(); 5338 5339 if (Verbose) { 5340 // decode some bytes around the PC 5341 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 5342 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 5343 address lowest = (address) dlinfo.dli_sname; 5344 if (!lowest) lowest = (address) dlinfo.dli_fbase; 5345 if (begin < lowest) begin = lowest; 5346 Dl_info dlinfo2; 5347 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 5348 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 5349 end = (address) dlinfo2.dli_saddr; 5350 } 5351 Disassembler::decode(begin, end, st); 5352 } 5353 return true; 5354 } 5355 return false; 5356 } 5357 5358 //////////////////////////////////////////////////////////////////////////////// 5359 // misc 5360 5361 // This does not do anything on Linux. This is basically a hook for being 5362 // able to use structured exception handling (thread-local exception filters) 5363 // on, e.g., Win32. 5364 void 5365 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, 5366 JavaCallArguments* args, Thread* thread) { 5367 f(value, method, args, thread); 5368 } 5369 5370 void os::print_statistics() { 5371 } 5372 5373 bool os::message_box(const char* title, const char* message) { 5374 int i; 5375 fdStream err(defaultStream::error_fd()); 5376 for (i = 0; i < 78; i++) err.print_raw("="); 5377 err.cr(); 5378 err.print_raw_cr(title); 5379 for (i = 0; i < 78; i++) err.print_raw("-"); 5380 err.cr(); 5381 err.print_raw_cr(message); 5382 for (i = 0; i < 78; i++) err.print_raw("="); 5383 err.cr(); 5384 5385 char buf[16]; 5386 // Prevent process from exiting upon "read error" without consuming all CPU 5387 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 5388 5389 return buf[0] == 'y' || buf[0] == 'Y'; 5390 } 5391 5392 // Is a (classpath) directory empty? 5393 bool os::dir_is_empty(const char* path) { 5394 DIR *dir = NULL; 5395 struct dirent *ptr; 5396 5397 dir = opendir(path); 5398 if (dir == NULL) return true; 5399 5400 // Scan the directory 5401 bool result = true; 5402 char buf[sizeof(struct dirent) + MAX_PATH]; 5403 while (result && (ptr = ::readdir(dir)) != NULL) { 5404 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 5405 result = false; 5406 } 5407 } 5408 closedir(dir); 5409 return result; 5410 } 5411 5412 // This code originates from JDK's sysOpen and open64_w 5413 // from src/solaris/hpi/src/system_md.c 5414 5415 int os::open(const char *path, int oflag, int mode) { 5416 if (strlen(path) > MAX_PATH - 1) { 5417 errno = ENAMETOOLONG; 5418 return -1; 5419 } 5420 5421 // All file descriptors that are opened in the Java process and not 5422 // specifically destined for a subprocess should have the close-on-exec 5423 // flag set. If we don't set it, then careless 3rd party native code 5424 // might fork and exec without closing all appropriate file descriptors 5425 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in 5426 // turn might: 5427 // 5428 // - cause end-of-file to fail to be detected on some file 5429 // descriptors, resulting in mysterious hangs, or 5430 // 5431 // - might cause an fopen in the subprocess to fail on a system 5432 // suffering from bug 1085341. 5433 // 5434 // (Yes, the default setting of the close-on-exec flag is a Unix 5435 // design flaw) 5436 // 5437 // See: 5438 // 1085341: 32-bit stdio routines should support file descriptors >255 5439 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 5440 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 5441 // 5442 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open(). 5443 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor 5444 // because it saves a system call and removes a small window where the flag 5445 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored 5446 // and we fall back to using FD_CLOEXEC (see below). 5447 #ifdef O_CLOEXEC 5448 oflag |= O_CLOEXEC; 5449 #endif 5450 5451 int fd = ::open64(path, oflag, mode); 5452 if (fd == -1) return -1; 5453 5454 //If the open succeeded, the file might still be a directory 5455 { 5456 struct stat64 buf64; 5457 int ret = ::fstat64(fd, &buf64); 5458 int st_mode = buf64.st_mode; 5459 5460 if (ret != -1) { 5461 if ((st_mode & S_IFMT) == S_IFDIR) { 5462 errno = EISDIR; 5463 ::close(fd); 5464 return -1; 5465 } 5466 } else { 5467 ::close(fd); 5468 return -1; 5469 } 5470 } 5471 5472 #ifdef FD_CLOEXEC 5473 // Validate that the use of the O_CLOEXEC flag on open above worked. 5474 // With recent kernels, we will perform this check exactly once. 5475 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0; 5476 if (!O_CLOEXEC_is_known_to_work) { 5477 int flags = ::fcntl(fd, F_GETFD); 5478 if (flags != -1) { 5479 if ((flags & FD_CLOEXEC) != 0) 5480 O_CLOEXEC_is_known_to_work = 1; 5481 else 5482 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 5483 } 5484 } 5485 #endif 5486 5487 return fd; 5488 } 5489 5490 5491 // create binary file, rewriting existing file if required 5492 int os::create_binary_file(const char* path, bool rewrite_existing) { 5493 int oflags = O_WRONLY | O_CREAT; 5494 if (!rewrite_existing) { 5495 oflags |= O_EXCL; 5496 } 5497 return ::open64(path, oflags, S_IREAD | S_IWRITE); 5498 } 5499 5500 // return current position of file pointer 5501 jlong os::current_file_offset(int fd) { 5502 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR); 5503 } 5504 5505 // move file pointer to the specified offset 5506 jlong os::seek_to_file_offset(int fd, jlong offset) { 5507 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET); 5508 } 5509 5510 // This code originates from JDK's sysAvailable 5511 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 5512 5513 int os::available(int fd, jlong *bytes) { 5514 jlong cur, end; 5515 int mode; 5516 struct stat64 buf64; 5517 5518 if (::fstat64(fd, &buf64) >= 0) { 5519 mode = buf64.st_mode; 5520 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 5521 int n; 5522 if (::ioctl(fd, FIONREAD, &n) >= 0) { 5523 *bytes = n; 5524 return 1; 5525 } 5526 } 5527 } 5528 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) { 5529 return 0; 5530 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) { 5531 return 0; 5532 } else if (::lseek64(fd, cur, SEEK_SET) == -1) { 5533 return 0; 5534 } 5535 *bytes = end - cur; 5536 return 1; 5537 } 5538 5539 // Map a block of memory. 5540 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 5541 char *addr, size_t bytes, bool read_only, 5542 bool allow_exec) { 5543 int prot; 5544 int flags = MAP_PRIVATE; 5545 5546 if (read_only) { 5547 prot = PROT_READ; 5548 } else { 5549 prot = PROT_READ | PROT_WRITE; 5550 } 5551 5552 if (allow_exec) { 5553 prot |= PROT_EXEC; 5554 } 5555 5556 if (addr != NULL) { 5557 flags |= MAP_FIXED; 5558 } 5559 5560 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 5561 fd, file_offset); 5562 if (mapped_address == MAP_FAILED) { 5563 return NULL; 5564 } 5565 return mapped_address; 5566 } 5567 5568 5569 // Remap a block of memory. 5570 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 5571 char *addr, size_t bytes, bool read_only, 5572 bool allow_exec) { 5573 // same as map_memory() on this OS 5574 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 5575 allow_exec); 5576 } 5577 5578 5579 // Unmap a block of memory. 5580 bool os::pd_unmap_memory(char* addr, size_t bytes) { 5581 return munmap(addr, bytes) == 0; 5582 } 5583 5584 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); 5585 5586 static clockid_t thread_cpu_clockid(Thread* thread) { 5587 pthread_t tid = thread->osthread()->pthread_id(); 5588 clockid_t clockid; 5589 5590 // Get thread clockid 5591 int rc = os::Linux::pthread_getcpuclockid(tid, &clockid); 5592 assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code"); 5593 return clockid; 5594 } 5595 5596 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 5597 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 5598 // of a thread. 5599 // 5600 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 5601 // the fast estimate available on the platform. 5602 5603 jlong os::current_thread_cpu_time() { 5604 if (os::Linux::supports_fast_thread_cpu_time()) { 5605 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5606 } else { 5607 // return user + sys since the cost is the same 5608 return slow_thread_cpu_time(Thread::current(), true /* user + sys */); 5609 } 5610 } 5611 5612 jlong os::thread_cpu_time(Thread* thread) { 5613 // consistent with what current_thread_cpu_time() returns 5614 if (os::Linux::supports_fast_thread_cpu_time()) { 5615 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5616 } else { 5617 return slow_thread_cpu_time(thread, true /* user + sys */); 5618 } 5619 } 5620 5621 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 5622 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5623 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5624 } else { 5625 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); 5626 } 5627 } 5628 5629 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5630 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5631 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5632 } else { 5633 return slow_thread_cpu_time(thread, user_sys_cpu_time); 5634 } 5635 } 5636 5637 // -1 on error. 5638 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5639 pid_t tid = thread->osthread()->thread_id(); 5640 char *s; 5641 char stat[2048]; 5642 int statlen; 5643 char proc_name[64]; 5644 int count; 5645 long sys_time, user_time; 5646 char cdummy; 5647 int idummy; 5648 long ldummy; 5649 FILE *fp; 5650 5651 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid); 5652 fp = fopen(proc_name, "r"); 5653 if (fp == NULL) return -1; 5654 statlen = fread(stat, 1, 2047, fp); 5655 stat[statlen] = '\0'; 5656 fclose(fp); 5657 5658 // Skip pid and the command string. Note that we could be dealing with 5659 // weird command names, e.g. user could decide to rename java launcher 5660 // to "java 1.4.2 :)", then the stat file would look like 5661 // 1234 (java 1.4.2 :)) R ... ... 5662 // We don't really need to know the command string, just find the last 5663 // occurrence of ")" and then start parsing from there. See bug 4726580. 5664 s = strrchr(stat, ')'); 5665 if (s == NULL) return -1; 5666 5667 // Skip blank chars 5668 do { s++; } while (s && isspace(*s)); 5669 5670 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", 5671 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy, 5672 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, 5673 &user_time, &sys_time); 5674 if (count != 13) return -1; 5675 if (user_sys_cpu_time) { 5676 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); 5677 } else { 5678 return (jlong)user_time * (1000000000 / clock_tics_per_sec); 5679 } 5680 } 5681 5682 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5683 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5684 info_ptr->may_skip_backward = false; // elapsed time not wall time 5685 info_ptr->may_skip_forward = false; // elapsed time not wall time 5686 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5687 } 5688 5689 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5690 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5691 info_ptr->may_skip_backward = false; // elapsed time not wall time 5692 info_ptr->may_skip_forward = false; // elapsed time not wall time 5693 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5694 } 5695 5696 bool os::is_thread_cpu_time_supported() { 5697 return true; 5698 } 5699 5700 // System loadavg support. Returns -1 if load average cannot be obtained. 5701 // Linux doesn't yet have a (official) notion of processor sets, 5702 // so just return the system wide load average. 5703 int os::loadavg(double loadavg[], int nelem) { 5704 return ::getloadavg(loadavg, nelem); 5705 } 5706 5707 void os::pause() { 5708 char filename[MAX_PATH]; 5709 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 5710 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile); 5711 } else { 5712 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 5713 } 5714 5715 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 5716 if (fd != -1) { 5717 struct stat buf; 5718 ::close(fd); 5719 while (::stat(filename, &buf) == 0) { 5720 (void)::poll(NULL, 0, 100); 5721 } 5722 } else { 5723 jio_fprintf(stderr, 5724 "Could not open pause file '%s', continuing immediately.\n", filename); 5725 } 5726 } 5727 5728 extern char** environ; 5729 5730 // Run the specified command in a separate process. Return its exit value, 5731 // or -1 on failure (e.g. can't fork a new process). 5732 // Unlike system(), this function can be called from signal handler. It 5733 // doesn't block SIGINT et al. 5734 int os::fork_and_exec(char* cmd) { 5735 const char * argv[4] = {"sh", "-c", cmd, NULL}; 5736 5737 pid_t pid = fork(); 5738 5739 if (pid < 0) { 5740 // fork failed 5741 return -1; 5742 5743 } else if (pid == 0) { 5744 // child process 5745 5746 execve("/bin/sh", (char* const*)argv, environ); 5747 5748 // execve failed 5749 _exit(-1); 5750 5751 } else { 5752 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 5753 // care about the actual exit code, for now. 5754 5755 int status; 5756 5757 // Wait for the child process to exit. This returns immediately if 5758 // the child has already exited. */ 5759 while (waitpid(pid, &status, 0) < 0) { 5760 switch (errno) { 5761 case ECHILD: return 0; 5762 case EINTR: break; 5763 default: return -1; 5764 } 5765 } 5766 5767 if (WIFEXITED(status)) { 5768 // The child exited normally; get its exit code. 5769 return WEXITSTATUS(status); 5770 } else if (WIFSIGNALED(status)) { 5771 // The child exited because of a signal 5772 // The best value to return is 0x80 + signal number, 5773 // because that is what all Unix shells do, and because 5774 // it allows callers to distinguish between process exit and 5775 // process death by signal. 5776 return 0x80 + WTERMSIG(status); 5777 } else { 5778 // Unknown exit code; pass it through 5779 return status; 5780 } 5781 } 5782 } 5783 5784 // Get the default path to the core file 5785 // Returns the length of the string 5786 int os::get_core_path(char* buffer, size_t bufferSize) { 5787 /* 5788 * Max length of /proc/sys/kernel/core_pattern is 128 characters. 5789 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt 5790 */ 5791 const int core_pattern_len = 129; 5792 char core_pattern[core_pattern_len] = {0}; 5793 5794 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY); 5795 if (core_pattern_file == -1) { 5796 return -1; 5797 } 5798 5799 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len); 5800 ::close(core_pattern_file); 5801 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') { 5802 return -1; 5803 } 5804 if (core_pattern[ret-1] == '\n') { 5805 core_pattern[ret-1] = '\0'; 5806 } else { 5807 core_pattern[ret] = '\0'; 5808 } 5809 5810 char *pid_pos = strstr(core_pattern, "%p"); 5811 int written; 5812 5813 if (core_pattern[0] == '/') { 5814 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern); 5815 } else { 5816 char cwd[PATH_MAX]; 5817 5818 const char* p = get_current_directory(cwd, PATH_MAX); 5819 if (p == NULL) { 5820 return -1; 5821 } 5822 5823 if (core_pattern[0] == '|') { 5824 written = jio_snprintf(buffer, bufferSize, 5825 "\"%s\" (or dumping to %s/core.%d)", 5826 &core_pattern[1], p, current_process_id()); 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