1 /* 2 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // no precompiled headers 26 #include "jvm.h" 27 #include "classfile/classLoader.hpp" 28 #include "classfile/systemDictionary.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "code/icBuffer.hpp" 31 #include "code/vtableStubs.hpp" 32 #include "compiler/compileBroker.hpp" 33 #include "compiler/disassembler.hpp" 34 #include "interpreter/interpreter.hpp" 35 #include "logging/log.hpp" 36 #include "memory/allocation.inline.hpp" 37 #include "memory/filemap.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "os_linux.inline.hpp" 40 #include "os_share_linux.hpp" 41 #include "osContainer_linux.hpp" 42 #include "prims/jniFastGetField.hpp" 43 #include "prims/jvm_misc.hpp" 44 #include "runtime/arguments.hpp" 45 #include "runtime/atomic.hpp" 46 #include "runtime/extendedPC.hpp" 47 #include "runtime/globals.hpp" 48 #include "runtime/interfaceSupport.inline.hpp" 49 #include "runtime/init.hpp" 50 #include "runtime/java.hpp" 51 #include "runtime/javaCalls.hpp" 52 #include "runtime/mutexLocker.hpp" 53 #include "runtime/objectMonitor.hpp" 54 #include "runtime/orderAccess.inline.hpp" 55 #include "runtime/osThread.hpp" 56 #include "runtime/perfMemory.hpp" 57 #include "runtime/sharedRuntime.hpp" 58 #include "runtime/statSampler.hpp" 59 #include "runtime/stubRoutines.hpp" 60 #include "runtime/thread.inline.hpp" 61 #include "runtime/threadCritical.hpp" 62 #include "runtime/threadSMR.hpp" 63 #include "runtime/timer.hpp" 64 #include "semaphore_posix.hpp" 65 #include "services/attachListener.hpp" 66 #include "services/memTracker.hpp" 67 #include "services/runtimeService.hpp" 68 #include "utilities/align.hpp" 69 #include "utilities/decoder.hpp" 70 #include "utilities/defaultStream.hpp" 71 #include "utilities/events.hpp" 72 #include "utilities/elfFile.hpp" 73 #include "utilities/growableArray.hpp" 74 #include "utilities/macros.hpp" 75 #include "utilities/vmError.hpp" 76 77 // put OS-includes here 78 # include <sys/types.h> 79 # include <sys/mman.h> 80 # include <sys/stat.h> 81 # include <sys/select.h> 82 # include <pthread.h> 83 # include <signal.h> 84 # include <errno.h> 85 # include <dlfcn.h> 86 # include <stdio.h> 87 # include <unistd.h> 88 # include <sys/resource.h> 89 # include <pthread.h> 90 # include <sys/stat.h> 91 # include <sys/time.h> 92 # include <sys/times.h> 93 # include <sys/utsname.h> 94 # include <sys/socket.h> 95 # include <sys/wait.h> 96 # include <pwd.h> 97 # include <poll.h> 98 # include <fcntl.h> 99 # include <string.h> 100 # include <syscall.h> 101 # include <sys/sysinfo.h> 102 # include <gnu/libc-version.h> 103 # include <sys/ipc.h> 104 # include <sys/shm.h> 105 # include <link.h> 106 # include <stdint.h> 107 # include <inttypes.h> 108 # include <sys/ioctl.h> 109 110 #ifndef _GNU_SOURCE 111 #define _GNU_SOURCE 112 #include <sched.h> 113 #undef _GNU_SOURCE 114 #else 115 #include <sched.h> 116 #endif 117 118 // if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling 119 // getrusage() is prepared to handle the associated failure. 120 #ifndef RUSAGE_THREAD 121 #define RUSAGE_THREAD (1) /* only the calling thread */ 122 #endif 123 124 #define MAX_PATH (2 * K) 125 126 #define MAX_SECS 100000000 127 128 // for timer info max values which include all bits 129 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 130 131 #define LARGEPAGES_BIT (1 << 6) 132 #define DAX_SHARED_BIT (1 << 8) 133 //////////////////////////////////////////////////////////////////////////////// 134 // global variables 135 julong os::Linux::_physical_memory = 0; 136 137 address os::Linux::_initial_thread_stack_bottom = NULL; 138 uintptr_t os::Linux::_initial_thread_stack_size = 0; 139 140 int (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL; 141 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL; 142 int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL; 143 Mutex* os::Linux::_createThread_lock = NULL; 144 pthread_t os::Linux::_main_thread; 145 int os::Linux::_page_size = -1; 146 bool os::Linux::_supports_fast_thread_cpu_time = false; 147 uint32_t os::Linux::_os_version = 0; 148 const char * os::Linux::_glibc_version = NULL; 149 const char * os::Linux::_libpthread_version = NULL; 150 151 static jlong initial_time_count=0; 152 153 static int clock_tics_per_sec = 100; 154 155 // For diagnostics to print a message once. see run_periodic_checks 156 static sigset_t check_signal_done; 157 static bool check_signals = true; 158 159 // Signal number used to suspend/resume a thread 160 161 // do not use any signal number less than SIGSEGV, see 4355769 162 static int SR_signum = SIGUSR2; 163 sigset_t SR_sigset; 164 165 // utility functions 166 167 static int SR_initialize(); 168 169 julong os::available_memory() { 170 return Linux::available_memory(); 171 } 172 173 julong os::Linux::available_memory() { 174 // values in struct sysinfo are "unsigned long" 175 struct sysinfo si; 176 julong avail_mem; 177 178 if (OSContainer::is_containerized()) { 179 jlong mem_limit, mem_usage; 180 if ((mem_limit = OSContainer::memory_limit_in_bytes()) < 1) { 181 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value", 182 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit); 183 } 184 if (mem_limit > 0 && (mem_usage = OSContainer::memory_usage_in_bytes()) < 1) { 185 log_debug(os, container)("container memory usage failed: " JLONG_FORMAT ", using host value", mem_usage); 186 } 187 if (mem_limit > 0 && mem_usage > 0 ) { 188 avail_mem = mem_limit > mem_usage ? (julong)mem_limit - (julong)mem_usage : 0; 189 log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem); 190 return avail_mem; 191 } 192 } 193 194 sysinfo(&si); 195 avail_mem = (julong)si.freeram * si.mem_unit; 196 log_trace(os)("available memory: " JULONG_FORMAT, avail_mem); 197 return avail_mem; 198 } 199 200 julong os::physical_memory() { 201 jlong phys_mem = 0; 202 if (OSContainer::is_containerized()) { 203 jlong mem_limit; 204 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) { 205 log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit); 206 return mem_limit; 207 } 208 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value", 209 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit); 210 } 211 212 phys_mem = Linux::physical_memory(); 213 log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem); 214 return phys_mem; 215 } 216 217 // Return true if user is running as root. 218 219 bool os::have_special_privileges() { 220 static bool init = false; 221 static bool privileges = false; 222 if (!init) { 223 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 224 init = true; 225 } 226 return privileges; 227 } 228 229 230 #ifndef SYS_gettid 231 // i386: 224, ia64: 1105, amd64: 186, sparc 143 232 #ifdef __ia64__ 233 #define SYS_gettid 1105 234 #else 235 #ifdef __i386__ 236 #define SYS_gettid 224 237 #else 238 #ifdef __amd64__ 239 #define SYS_gettid 186 240 #else 241 #ifdef __sparc__ 242 #define SYS_gettid 143 243 #else 244 #error define gettid for the arch 245 #endif 246 #endif 247 #endif 248 #endif 249 #endif 250 251 252 // pid_t gettid() 253 // 254 // Returns the kernel thread id of the currently running thread. Kernel 255 // thread id is used to access /proc. 256 pid_t os::Linux::gettid() { 257 int rslt = syscall(SYS_gettid); 258 assert(rslt != -1, "must be."); // old linuxthreads implementation? 259 return (pid_t)rslt; 260 } 261 262 // Most versions of linux have a bug where the number of processors are 263 // determined by looking at the /proc file system. In a chroot environment, 264 // the system call returns 1. This causes the VM to act as if it is 265 // a single processor and elide locking (see is_MP() call). 266 static bool unsafe_chroot_detected = false; 267 static const char *unstable_chroot_error = "/proc file system not found.\n" 268 "Java may be unstable running multithreaded in a chroot " 269 "environment on Linux when /proc filesystem is not mounted."; 270 271 void os::Linux::initialize_system_info() { 272 set_processor_count(sysconf(_SC_NPROCESSORS_CONF)); 273 if (processor_count() == 1) { 274 pid_t pid = os::Linux::gettid(); 275 char fname[32]; 276 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid); 277 FILE *fp = fopen(fname, "r"); 278 if (fp == NULL) { 279 unsafe_chroot_detected = true; 280 } else { 281 fclose(fp); 282 } 283 } 284 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE); 285 assert(processor_count() > 0, "linux error"); 286 } 287 288 void os::init_system_properties_values() { 289 // The next steps are taken in the product version: 290 // 291 // Obtain the JAVA_HOME value from the location of libjvm.so. 292 // This library should be located at: 293 // <JAVA_HOME>/lib/{client|server}/libjvm.so. 294 // 295 // If "/jre/lib/" appears at the right place in the path, then we 296 // assume libjvm.so is installed in a JDK and we use this path. 297 // 298 // Otherwise exit with message: "Could not create the Java virtual machine." 299 // 300 // The following extra steps are taken in the debugging version: 301 // 302 // If "/jre/lib/" does NOT appear at the right place in the path 303 // instead of exit check for $JAVA_HOME environment variable. 304 // 305 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 306 // then we append a fake suffix "hotspot/libjvm.so" to this path so 307 // it looks like libjvm.so is installed there 308 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 309 // 310 // Otherwise exit. 311 // 312 // Important note: if the location of libjvm.so changes this 313 // code needs to be changed accordingly. 314 315 // See ld(1): 316 // The linker uses the following search paths to locate required 317 // shared libraries: 318 // 1: ... 319 // ... 320 // 7: The default directories, normally /lib and /usr/lib. 321 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390) 322 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib" 323 #else 324 #define DEFAULT_LIBPATH "/lib:/usr/lib" 325 #endif 326 327 // Base path of extensions installed on the system. 328 #define SYS_EXT_DIR "/usr/java/packages" 329 #define EXTENSIONS_DIR "/lib/ext" 330 331 // Buffer that fits several sprintfs. 332 // Note that the space for the colon and the trailing null are provided 333 // by the nulls included by the sizeof operator. 334 const size_t bufsize = 335 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 336 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 337 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 338 339 // sysclasspath, java_home, dll_dir 340 { 341 char *pslash; 342 os::jvm_path(buf, bufsize); 343 344 // Found the full path to libjvm.so. 345 // Now cut the path to <java_home>/jre if we can. 346 pslash = strrchr(buf, '/'); 347 if (pslash != NULL) { 348 *pslash = '\0'; // Get rid of /libjvm.so. 349 } 350 pslash = strrchr(buf, '/'); 351 if (pslash != NULL) { 352 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 353 } 354 Arguments::set_dll_dir(buf); 355 356 if (pslash != NULL) { 357 pslash = strrchr(buf, '/'); 358 if (pslash != NULL) { 359 *pslash = '\0'; // Get rid of /lib. 360 } 361 } 362 Arguments::set_java_home(buf); 363 set_boot_path('/', ':'); 364 } 365 366 // Where to look for native libraries. 367 // 368 // Note: Due to a legacy implementation, most of the library path 369 // is set in the launcher. This was to accomodate linking restrictions 370 // on legacy Linux implementations (which are no longer supported). 371 // Eventually, all the library path setting will be done here. 372 // 373 // However, to prevent the proliferation of improperly built native 374 // libraries, the new path component /usr/java/packages is added here. 375 // Eventually, all the library path setting will be done here. 376 { 377 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 378 // should always exist (until the legacy problem cited above is 379 // addressed). 380 const char *v = ::getenv("LD_LIBRARY_PATH"); 381 const char *v_colon = ":"; 382 if (v == NULL) { v = ""; v_colon = ""; } 383 // That's +1 for the colon and +1 for the trailing '\0'. 384 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 385 strlen(v) + 1 + 386 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1, 387 mtInternal); 388 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon); 389 Arguments::set_library_path(ld_library_path); 390 FREE_C_HEAP_ARRAY(char, ld_library_path); 391 } 392 393 // Extensions directories. 394 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 395 Arguments::set_ext_dirs(buf); 396 397 FREE_C_HEAP_ARRAY(char, buf); 398 399 #undef DEFAULT_LIBPATH 400 #undef SYS_EXT_DIR 401 #undef EXTENSIONS_DIR 402 } 403 404 //////////////////////////////////////////////////////////////////////////////// 405 // breakpoint support 406 407 void os::breakpoint() { 408 BREAKPOINT; 409 } 410 411 extern "C" void breakpoint() { 412 // use debugger to set breakpoint here 413 } 414 415 //////////////////////////////////////////////////////////////////////////////// 416 // signal support 417 418 debug_only(static bool signal_sets_initialized = false); 419 static sigset_t unblocked_sigs, vm_sigs; 420 421 bool os::Linux::is_sig_ignored(int sig) { 422 struct sigaction oact; 423 sigaction(sig, (struct sigaction*)NULL, &oact); 424 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 425 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 426 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 427 return true; 428 } else { 429 return false; 430 } 431 } 432 433 void os::Linux::signal_sets_init() { 434 // Should also have an assertion stating we are still single-threaded. 435 assert(!signal_sets_initialized, "Already initialized"); 436 // Fill in signals that are necessarily unblocked for all threads in 437 // the VM. Currently, we unblock the following signals: 438 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 439 // by -Xrs (=ReduceSignalUsage)); 440 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 441 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 442 // the dispositions or masks wrt these signals. 443 // Programs embedding the VM that want to use the above signals for their 444 // own purposes must, at this time, use the "-Xrs" option to prevent 445 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 446 // (See bug 4345157, and other related bugs). 447 // In reality, though, unblocking these signals is really a nop, since 448 // these signals are not blocked by default. 449 sigemptyset(&unblocked_sigs); 450 sigaddset(&unblocked_sigs, SIGILL); 451 sigaddset(&unblocked_sigs, SIGSEGV); 452 sigaddset(&unblocked_sigs, SIGBUS); 453 sigaddset(&unblocked_sigs, SIGFPE); 454 #if defined(PPC64) 455 sigaddset(&unblocked_sigs, SIGTRAP); 456 #endif 457 sigaddset(&unblocked_sigs, SR_signum); 458 459 if (!ReduceSignalUsage) { 460 if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 461 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 462 } 463 if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 464 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 465 } 466 if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 467 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 468 } 469 } 470 // Fill in signals that are blocked by all but the VM thread. 471 sigemptyset(&vm_sigs); 472 if (!ReduceSignalUsage) { 473 sigaddset(&vm_sigs, BREAK_SIGNAL); 474 } 475 debug_only(signal_sets_initialized = true); 476 477 } 478 479 // These are signals that are unblocked while a thread is running Java. 480 // (For some reason, they get blocked by default.) 481 sigset_t* os::Linux::unblocked_signals() { 482 assert(signal_sets_initialized, "Not initialized"); 483 return &unblocked_sigs; 484 } 485 486 // These are the signals that are blocked while a (non-VM) thread is 487 // running Java. Only the VM thread handles these signals. 488 sigset_t* os::Linux::vm_signals() { 489 assert(signal_sets_initialized, "Not initialized"); 490 return &vm_sigs; 491 } 492 493 void os::Linux::hotspot_sigmask(Thread* thread) { 494 495 //Save caller's signal mask before setting VM signal mask 496 sigset_t caller_sigmask; 497 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 498 499 OSThread* osthread = thread->osthread(); 500 osthread->set_caller_sigmask(caller_sigmask); 501 502 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL); 503 504 if (!ReduceSignalUsage) { 505 if (thread->is_VM_thread()) { 506 // Only the VM thread handles BREAK_SIGNAL ... 507 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 508 } else { 509 // ... all other threads block BREAK_SIGNAL 510 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 511 } 512 } 513 } 514 515 ////////////////////////////////////////////////////////////////////////////// 516 // detecting pthread library 517 518 void os::Linux::libpthread_init() { 519 // Save glibc and pthread version strings. 520 #if !defined(_CS_GNU_LIBC_VERSION) || \ 521 !defined(_CS_GNU_LIBPTHREAD_VERSION) 522 #error "glibc too old (< 2.3.2)" 523 #endif 524 525 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); 526 assert(n > 0, "cannot retrieve glibc version"); 527 char *str = (char *)malloc(n, mtInternal); 528 confstr(_CS_GNU_LIBC_VERSION, str, n); 529 os::Linux::set_glibc_version(str); 530 531 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); 532 assert(n > 0, "cannot retrieve pthread version"); 533 str = (char *)malloc(n, mtInternal); 534 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); 535 os::Linux::set_libpthread_version(str); 536 } 537 538 ///////////////////////////////////////////////////////////////////////////// 539 // thread stack expansion 540 541 // os::Linux::manually_expand_stack() takes care of expanding the thread 542 // stack. Note that this is normally not needed: pthread stacks allocate 543 // thread stack using mmap() without MAP_NORESERVE, so the stack is already 544 // committed. Therefore it is not necessary to expand the stack manually. 545 // 546 // Manually expanding the stack was historically needed on LinuxThreads 547 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays 548 // it is kept to deal with very rare corner cases: 549 // 550 // For one, user may run the VM on an own implementation of threads 551 // whose stacks are - like the old LinuxThreads - implemented using 552 // mmap(MAP_GROWSDOWN). 553 // 554 // Also, this coding may be needed if the VM is running on the primordial 555 // thread. Normally we avoid running on the primordial thread; however, 556 // user may still invoke the VM on the primordial thread. 557 // 558 // The following historical comment describes the details about running 559 // on a thread stack allocated with mmap(MAP_GROWSDOWN): 560 561 562 // Force Linux kernel to expand current thread stack. If "bottom" is close 563 // to the stack guard, caller should block all signals. 564 // 565 // MAP_GROWSDOWN: 566 // A special mmap() flag that is used to implement thread stacks. It tells 567 // kernel that the memory region should extend downwards when needed. This 568 // allows early versions of LinuxThreads to only mmap the first few pages 569 // when creating a new thread. Linux kernel will automatically expand thread 570 // stack as needed (on page faults). 571 // 572 // However, because the memory region of a MAP_GROWSDOWN stack can grow on 573 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN 574 // region, it's hard to tell if the fault is due to a legitimate stack 575 // access or because of reading/writing non-exist memory (e.g. buffer 576 // overrun). As a rule, if the fault happens below current stack pointer, 577 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the 578 // application (see Linux kernel fault.c). 579 // 580 // This Linux feature can cause SIGSEGV when VM bangs thread stack for 581 // stack overflow detection. 582 // 583 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do 584 // not use MAP_GROWSDOWN. 585 // 586 // To get around the problem and allow stack banging on Linux, we need to 587 // manually expand thread stack after receiving the SIGSEGV. 588 // 589 // There are two ways to expand thread stack to address "bottom", we used 590 // both of them in JVM before 1.5: 591 // 1. adjust stack pointer first so that it is below "bottom", and then 592 // touch "bottom" 593 // 2. mmap() the page in question 594 // 595 // Now alternate signal stack is gone, it's harder to use 2. For instance, 596 // if current sp is already near the lower end of page 101, and we need to 597 // call mmap() to map page 100, it is possible that part of the mmap() frame 598 // will be placed in page 100. When page 100 is mapped, it is zero-filled. 599 // That will destroy the mmap() frame and cause VM to crash. 600 // 601 // The following code works by adjusting sp first, then accessing the "bottom" 602 // page to force a page fault. Linux kernel will then automatically expand the 603 // stack mapping. 604 // 605 // _expand_stack_to() assumes its frame size is less than page size, which 606 // should always be true if the function is not inlined. 607 608 static void NOINLINE _expand_stack_to(address bottom) { 609 address sp; 610 size_t size; 611 volatile char *p; 612 613 // Adjust bottom to point to the largest address within the same page, it 614 // gives us a one-page buffer if alloca() allocates slightly more memory. 615 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size()); 616 bottom += os::Linux::page_size() - 1; 617 618 // sp might be slightly above current stack pointer; if that's the case, we 619 // will alloca() a little more space than necessary, which is OK. Don't use 620 // os::current_stack_pointer(), as its result can be slightly below current 621 // stack pointer, causing us to not alloca enough to reach "bottom". 622 sp = (address)&sp; 623 624 if (sp > bottom) { 625 size = sp - bottom; 626 p = (volatile char *)alloca(size); 627 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); 628 p[0] = '\0'; 629 } 630 } 631 632 void os::Linux::expand_stack_to(address bottom) { 633 _expand_stack_to(bottom); 634 } 635 636 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) { 637 assert(t!=NULL, "just checking"); 638 assert(t->osthread()->expanding_stack(), "expand should be set"); 639 assert(t->stack_base() != NULL, "stack_base was not initialized"); 640 641 if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) { 642 sigset_t mask_all, old_sigset; 643 sigfillset(&mask_all); 644 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); 645 _expand_stack_to(addr); 646 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); 647 return true; 648 } 649 return false; 650 } 651 652 ////////////////////////////////////////////////////////////////////////////// 653 // create new thread 654 655 // Thread start routine for all newly created threads 656 static void *thread_native_entry(Thread *thread) { 657 // Try to randomize the cache line index of hot stack frames. 658 // This helps when threads of the same stack traces evict each other's 659 // cache lines. The threads can be either from the same JVM instance, or 660 // from different JVM instances. The benefit is especially true for 661 // processors with hyperthreading technology. 662 static int counter = 0; 663 int pid = os::current_process_id(); 664 alloca(((pid ^ counter++) & 7) * 128); 665 666 thread->initialize_thread_current(); 667 668 OSThread* osthread = thread->osthread(); 669 Monitor* sync = osthread->startThread_lock(); 670 671 osthread->set_thread_id(os::current_thread_id()); 672 673 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 674 os::current_thread_id(), (uintx) pthread_self()); 675 676 if (UseNUMA) { 677 int lgrp_id = os::numa_get_group_id(); 678 if (lgrp_id != -1) { 679 thread->set_lgrp_id(lgrp_id); 680 } 681 } 682 // initialize signal mask for this thread 683 os::Linux::hotspot_sigmask(thread); 684 685 // initialize floating point control register 686 os::Linux::init_thread_fpu_state(); 687 688 // handshaking with parent thread 689 { 690 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 691 692 // notify parent thread 693 osthread->set_state(INITIALIZED); 694 sync->notify_all(); 695 696 // wait until os::start_thread() 697 while (osthread->get_state() == INITIALIZED) { 698 sync->wait(Mutex::_no_safepoint_check_flag); 699 } 700 } 701 702 // call one more level start routine 703 thread->run(); 704 705 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 706 os::current_thread_id(), (uintx) pthread_self()); 707 708 // If a thread has not deleted itself ("delete this") as part of its 709 // termination sequence, we have to ensure thread-local-storage is 710 // cleared before we actually terminate. No threads should ever be 711 // deleted asynchronously with respect to their termination. 712 if (Thread::current_or_null_safe() != NULL) { 713 assert(Thread::current_or_null_safe() == thread, "current thread is wrong"); 714 thread->clear_thread_current(); 715 } 716 717 return 0; 718 } 719 720 bool os::create_thread(Thread* thread, ThreadType thr_type, 721 size_t req_stack_size) { 722 assert(thread->osthread() == NULL, "caller responsible"); 723 724 // Allocate the OSThread object 725 OSThread* osthread = new OSThread(NULL, NULL); 726 if (osthread == NULL) { 727 return false; 728 } 729 730 // set the correct thread state 731 osthread->set_thread_type(thr_type); 732 733 // Initial state is ALLOCATED but not INITIALIZED 734 osthread->set_state(ALLOCATED); 735 736 thread->set_osthread(osthread); 737 738 // init thread attributes 739 pthread_attr_t attr; 740 pthread_attr_init(&attr); 741 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 742 743 // Calculate stack size if it's not specified by caller. 744 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size); 745 // In the Linux NPTL pthread implementation the guard size mechanism 746 // is not implemented properly. The posix standard requires adding 747 // the size of the guard pages to the stack size, instead Linux 748 // takes the space out of 'stacksize'. Thus we adapt the requested 749 // stack_size by the size of the guard pages to mimick proper 750 // behaviour. However, be careful not to end up with a size 751 // of zero due to overflow. Don't add the guard page in that case. 752 size_t guard_size = os::Linux::default_guard_size(thr_type); 753 if (stack_size <= SIZE_MAX - guard_size) { 754 stack_size += guard_size; 755 } 756 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned"); 757 758 int status = pthread_attr_setstacksize(&attr, stack_size); 759 assert_status(status == 0, status, "pthread_attr_setstacksize"); 760 761 // Configure glibc guard page. 762 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); 763 764 ThreadState state; 765 766 { 767 pthread_t tid; 768 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread); 769 770 char buf[64]; 771 if (ret == 0) { 772 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ", 773 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 774 } else { 775 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.", 776 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 777 } 778 779 pthread_attr_destroy(&attr); 780 781 if (ret != 0) { 782 // Need to clean up stuff we've allocated so far 783 thread->set_osthread(NULL); 784 delete osthread; 785 return false; 786 } 787 788 // Store pthread info into the OSThread 789 osthread->set_pthread_id(tid); 790 791 // Wait until child thread is either initialized or aborted 792 { 793 Monitor* sync_with_child = osthread->startThread_lock(); 794 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 795 while ((state = osthread->get_state()) == ALLOCATED) { 796 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 797 } 798 } 799 } 800 801 // Aborted due to thread limit being reached 802 if (state == ZOMBIE) { 803 thread->set_osthread(NULL); 804 delete osthread; 805 return false; 806 } 807 808 // The thread is returned suspended (in state INITIALIZED), 809 // and is started higher up in the call chain 810 assert(state == INITIALIZED, "race condition"); 811 return true; 812 } 813 814 ///////////////////////////////////////////////////////////////////////////// 815 // attach existing thread 816 817 // bootstrap the main thread 818 bool os::create_main_thread(JavaThread* thread) { 819 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread"); 820 return create_attached_thread(thread); 821 } 822 823 bool os::create_attached_thread(JavaThread* thread) { 824 #ifdef ASSERT 825 thread->verify_not_published(); 826 #endif 827 828 // Allocate the OSThread object 829 OSThread* osthread = new OSThread(NULL, NULL); 830 831 if (osthread == NULL) { 832 return false; 833 } 834 835 // Store pthread info into the OSThread 836 osthread->set_thread_id(os::Linux::gettid()); 837 osthread->set_pthread_id(::pthread_self()); 838 839 // initialize floating point control register 840 os::Linux::init_thread_fpu_state(); 841 842 // Initial thread state is RUNNABLE 843 osthread->set_state(RUNNABLE); 844 845 thread->set_osthread(osthread); 846 847 if (UseNUMA) { 848 int lgrp_id = os::numa_get_group_id(); 849 if (lgrp_id != -1) { 850 thread->set_lgrp_id(lgrp_id); 851 } 852 } 853 854 if (os::is_primordial_thread()) { 855 // If current thread is primordial thread, its stack is mapped on demand, 856 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map 857 // the entire stack region to avoid SEGV in stack banging. 858 // It is also useful to get around the heap-stack-gap problem on SuSE 859 // kernel (see 4821821 for details). We first expand stack to the top 860 // of yellow zone, then enable stack yellow zone (order is significant, 861 // enabling yellow zone first will crash JVM on SuSE Linux), so there 862 // is no gap between the last two virtual memory regions. 863 864 JavaThread *jt = (JavaThread *)thread; 865 address addr = jt->stack_reserved_zone_base(); 866 assert(addr != NULL, "initialization problem?"); 867 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); 868 869 osthread->set_expanding_stack(); 870 os::Linux::manually_expand_stack(jt, addr); 871 osthread->clear_expanding_stack(); 872 } 873 874 // initialize signal mask for this thread 875 // and save the caller's signal mask 876 os::Linux::hotspot_sigmask(thread); 877 878 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 879 os::current_thread_id(), (uintx) pthread_self()); 880 881 return true; 882 } 883 884 void os::pd_start_thread(Thread* thread) { 885 OSThread * osthread = thread->osthread(); 886 assert(osthread->get_state() != INITIALIZED, "just checking"); 887 Monitor* sync_with_child = osthread->startThread_lock(); 888 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 889 sync_with_child->notify(); 890 } 891 892 // Free Linux resources related to the OSThread 893 void os::free_thread(OSThread* osthread) { 894 assert(osthread != NULL, "osthread not set"); 895 896 // We are told to free resources of the argument thread, 897 // but we can only really operate on the current thread. 898 assert(Thread::current()->osthread() == osthread, 899 "os::free_thread but not current thread"); 900 901 #ifdef ASSERT 902 sigset_t current; 903 sigemptyset(¤t); 904 pthread_sigmask(SIG_SETMASK, NULL, ¤t); 905 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!"); 906 #endif 907 908 // Restore caller's signal mask 909 sigset_t sigmask = osthread->caller_sigmask(); 910 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 911 912 delete osthread; 913 } 914 915 ////////////////////////////////////////////////////////////////////////////// 916 // primordial thread 917 918 // Check if current thread is the primordial thread, similar to Solaris thr_main. 919 bool os::is_primordial_thread(void) { 920 char dummy; 921 // If called before init complete, thread stack bottom will be null. 922 // Can be called if fatal error occurs before initialization. 923 if (os::Linux::initial_thread_stack_bottom() == NULL) return false; 924 assert(os::Linux::initial_thread_stack_bottom() != NULL && 925 os::Linux::initial_thread_stack_size() != 0, 926 "os::init did not locate primordial thread's stack region"); 927 if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() && 928 (address)&dummy < os::Linux::initial_thread_stack_bottom() + 929 os::Linux::initial_thread_stack_size()) { 930 return true; 931 } else { 932 return false; 933 } 934 } 935 936 // Find the virtual memory area that contains addr 937 static bool find_vma(address addr, address* vma_low, address* vma_high) { 938 FILE *fp = fopen("/proc/self/maps", "r"); 939 if (fp) { 940 address low, high; 941 while (!feof(fp)) { 942 if (fscanf(fp, "%p-%p", &low, &high) == 2) { 943 if (low <= addr && addr < high) { 944 if (vma_low) *vma_low = low; 945 if (vma_high) *vma_high = high; 946 fclose(fp); 947 return true; 948 } 949 } 950 for (;;) { 951 int ch = fgetc(fp); 952 if (ch == EOF || ch == (int)'\n') break; 953 } 954 } 955 fclose(fp); 956 } 957 return false; 958 } 959 960 // Locate primordial thread stack. This special handling of primordial thread stack 961 // is needed because pthread_getattr_np() on most (all?) Linux distros returns 962 // bogus value for the primordial process thread. While the launcher has created 963 // the VM in a new thread since JDK 6, we still have to allow for the use of the 964 // JNI invocation API from a primordial thread. 965 void os::Linux::capture_initial_stack(size_t max_size) { 966 967 // max_size is either 0 (which means accept OS default for thread stacks) or 968 // a user-specified value known to be at least the minimum needed. If we 969 // are actually on the primordial thread we can make it appear that we have a 970 // smaller max_size stack by inserting the guard pages at that location. But we 971 // cannot do anything to emulate a larger stack than what has been provided by 972 // the OS or threading library. In fact if we try to use a stack greater than 973 // what is set by rlimit then we will crash the hosting process. 974 975 // Maximum stack size is the easy part, get it from RLIMIT_STACK. 976 // If this is "unlimited" then it will be a huge value. 977 struct rlimit rlim; 978 getrlimit(RLIMIT_STACK, &rlim); 979 size_t stack_size = rlim.rlim_cur; 980 981 // 6308388: a bug in ld.so will relocate its own .data section to the 982 // lower end of primordial stack; reduce ulimit -s value a little bit 983 // so we won't install guard page on ld.so's data section. 984 // But ensure we don't underflow the stack size - allow 1 page spare 985 if (stack_size >= (size_t)(3 * page_size())) { 986 stack_size -= 2 * page_size(); 987 } 988 989 // Try to figure out where the stack base (top) is. This is harder. 990 // 991 // When an application is started, glibc saves the initial stack pointer in 992 // a global variable "__libc_stack_end", which is then used by system 993 // libraries. __libc_stack_end should be pretty close to stack top. The 994 // variable is available since the very early days. However, because it is 995 // a private interface, it could disappear in the future. 996 // 997 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar 998 // to __libc_stack_end, it is very close to stack top, but isn't the real 999 // stack top. Note that /proc may not exist if VM is running as a chroot 1000 // program, so reading /proc/<pid>/stat could fail. Also the contents of 1001 // /proc/<pid>/stat could change in the future (though unlikely). 1002 // 1003 // We try __libc_stack_end first. If that doesn't work, look for 1004 // /proc/<pid>/stat. If neither of them works, we use current stack pointer 1005 // as a hint, which should work well in most cases. 1006 1007 uintptr_t stack_start; 1008 1009 // try __libc_stack_end first 1010 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end"); 1011 if (p && *p) { 1012 stack_start = *p; 1013 } else { 1014 // see if we can get the start_stack field from /proc/self/stat 1015 FILE *fp; 1016 int pid; 1017 char state; 1018 int ppid; 1019 int pgrp; 1020 int session; 1021 int nr; 1022 int tpgrp; 1023 unsigned long flags; 1024 unsigned long minflt; 1025 unsigned long cminflt; 1026 unsigned long majflt; 1027 unsigned long cmajflt; 1028 unsigned long utime; 1029 unsigned long stime; 1030 long cutime; 1031 long cstime; 1032 long prio; 1033 long nice; 1034 long junk; 1035 long it_real; 1036 uintptr_t start; 1037 uintptr_t vsize; 1038 intptr_t rss; 1039 uintptr_t rsslim; 1040 uintptr_t scodes; 1041 uintptr_t ecode; 1042 int i; 1043 1044 // Figure what the primordial thread stack base is. Code is inspired 1045 // by email from Hans Boehm. /proc/self/stat begins with current pid, 1046 // followed by command name surrounded by parentheses, state, etc. 1047 char stat[2048]; 1048 int statlen; 1049 1050 fp = fopen("/proc/self/stat", "r"); 1051 if (fp) { 1052 statlen = fread(stat, 1, 2047, fp); 1053 stat[statlen] = '\0'; 1054 fclose(fp); 1055 1056 // Skip pid and the command string. Note that we could be dealing with 1057 // weird command names, e.g. user could decide to rename java launcher 1058 // to "java 1.4.2 :)", then the stat file would look like 1059 // 1234 (java 1.4.2 :)) R ... ... 1060 // We don't really need to know the command string, just find the last 1061 // occurrence of ")" and then start parsing from there. See bug 4726580. 1062 char * s = strrchr(stat, ')'); 1063 1064 i = 0; 1065 if (s) { 1066 // Skip blank chars 1067 do { s++; } while (s && isspace(*s)); 1068 1069 #define _UFM UINTX_FORMAT 1070 #define _DFM INTX_FORMAT 1071 1072 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 1073 // 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 1074 i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM, 1075 &state, // 3 %c 1076 &ppid, // 4 %d 1077 &pgrp, // 5 %d 1078 &session, // 6 %d 1079 &nr, // 7 %d 1080 &tpgrp, // 8 %d 1081 &flags, // 9 %lu 1082 &minflt, // 10 %lu 1083 &cminflt, // 11 %lu 1084 &majflt, // 12 %lu 1085 &cmajflt, // 13 %lu 1086 &utime, // 14 %lu 1087 &stime, // 15 %lu 1088 &cutime, // 16 %ld 1089 &cstime, // 17 %ld 1090 &prio, // 18 %ld 1091 &nice, // 19 %ld 1092 &junk, // 20 %ld 1093 &it_real, // 21 %ld 1094 &start, // 22 UINTX_FORMAT 1095 &vsize, // 23 UINTX_FORMAT 1096 &rss, // 24 INTX_FORMAT 1097 &rsslim, // 25 UINTX_FORMAT 1098 &scodes, // 26 UINTX_FORMAT 1099 &ecode, // 27 UINTX_FORMAT 1100 &stack_start); // 28 UINTX_FORMAT 1101 } 1102 1103 #undef _UFM 1104 #undef _DFM 1105 1106 if (i != 28 - 2) { 1107 assert(false, "Bad conversion from /proc/self/stat"); 1108 // product mode - assume we are the primordial thread, good luck in the 1109 // embedded case. 1110 warning("Can't detect primordial thread stack location - bad conversion"); 1111 stack_start = (uintptr_t) &rlim; 1112 } 1113 } else { 1114 // For some reason we can't open /proc/self/stat (for example, running on 1115 // FreeBSD with a Linux emulator, or inside chroot), this should work for 1116 // most cases, so don't abort: 1117 warning("Can't detect primordial thread stack location - no /proc/self/stat"); 1118 stack_start = (uintptr_t) &rlim; 1119 } 1120 } 1121 1122 // Now we have a pointer (stack_start) very close to the stack top, the 1123 // next thing to do is to figure out the exact location of stack top. We 1124 // can find out the virtual memory area that contains stack_start by 1125 // reading /proc/self/maps, it should be the last vma in /proc/self/maps, 1126 // and its upper limit is the real stack top. (again, this would fail if 1127 // running inside chroot, because /proc may not exist.) 1128 1129 uintptr_t stack_top; 1130 address low, high; 1131 if (find_vma((address)stack_start, &low, &high)) { 1132 // success, "high" is the true stack top. (ignore "low", because initial 1133 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.) 1134 stack_top = (uintptr_t)high; 1135 } else { 1136 // failed, likely because /proc/self/maps does not exist 1137 warning("Can't detect primordial thread stack location - find_vma failed"); 1138 // best effort: stack_start is normally within a few pages below the real 1139 // stack top, use it as stack top, and reduce stack size so we won't put 1140 // guard page outside stack. 1141 stack_top = stack_start; 1142 stack_size -= 16 * page_size(); 1143 } 1144 1145 // stack_top could be partially down the page so align it 1146 stack_top = align_up(stack_top, page_size()); 1147 1148 // Allowed stack value is minimum of max_size and what we derived from rlimit 1149 if (max_size > 0) { 1150 _initial_thread_stack_size = MIN2(max_size, stack_size); 1151 } else { 1152 // Accept the rlimit max, but if stack is unlimited then it will be huge, so 1153 // clamp it at 8MB as we do on Solaris 1154 _initial_thread_stack_size = MIN2(stack_size, 8*M); 1155 } 1156 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size()); 1157 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; 1158 1159 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!"); 1160 1161 if (log_is_enabled(Info, os, thread)) { 1162 // See if we seem to be on primordial process thread 1163 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) && 1164 uintptr_t(&rlim) < stack_top; 1165 1166 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: " 1167 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT, 1168 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K, 1169 stack_top, intptr_t(_initial_thread_stack_bottom)); 1170 } 1171 } 1172 1173 //////////////////////////////////////////////////////////////////////////////// 1174 // time support 1175 1176 // Time since start-up in seconds to a fine granularity. 1177 // Used by VMSelfDestructTimer and the MemProfiler. 1178 double os::elapsedTime() { 1179 1180 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution 1181 } 1182 1183 jlong os::elapsed_counter() { 1184 return javaTimeNanos() - initial_time_count; 1185 } 1186 1187 jlong os::elapsed_frequency() { 1188 return NANOSECS_PER_SEC; // nanosecond resolution 1189 } 1190 1191 bool os::supports_vtime() { return true; } 1192 bool os::enable_vtime() { return false; } 1193 bool os::vtime_enabled() { return false; } 1194 1195 double os::elapsedVTime() { 1196 struct rusage usage; 1197 int retval = getrusage(RUSAGE_THREAD, &usage); 1198 if (retval == 0) { 1199 return (double) (usage.ru_utime.tv_sec + usage.ru_stime.tv_sec) + (double) (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000 * 1000); 1200 } else { 1201 // better than nothing, but not much 1202 return elapsedTime(); 1203 } 1204 } 1205 1206 jlong os::javaTimeMillis() { 1207 timeval time; 1208 int status = gettimeofday(&time, NULL); 1209 assert(status != -1, "linux error"); 1210 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 1211 } 1212 1213 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { 1214 timeval time; 1215 int status = gettimeofday(&time, NULL); 1216 assert(status != -1, "linux error"); 1217 seconds = jlong(time.tv_sec); 1218 nanos = jlong(time.tv_usec) * 1000; 1219 } 1220 1221 1222 #ifndef CLOCK_MONOTONIC 1223 #define CLOCK_MONOTONIC (1) 1224 #endif 1225 1226 void os::Linux::clock_init() { 1227 // we do dlopen's in this particular order due to bug in linux 1228 // dynamical loader (see 6348968) leading to crash on exit 1229 void* handle = dlopen("librt.so.1", RTLD_LAZY); 1230 if (handle == NULL) { 1231 handle = dlopen("librt.so", RTLD_LAZY); 1232 } 1233 1234 if (handle) { 1235 int (*clock_getres_func)(clockid_t, struct timespec*) = 1236 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres"); 1237 int (*clock_gettime_func)(clockid_t, struct timespec*) = 1238 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime"); 1239 if (clock_getres_func && clock_gettime_func) { 1240 // See if monotonic clock is supported by the kernel. Note that some 1241 // early implementations simply return kernel jiffies (updated every 1242 // 1/100 or 1/1000 second). It would be bad to use such a low res clock 1243 // for nano time (though the monotonic property is still nice to have). 1244 // It's fixed in newer kernels, however clock_getres() still returns 1245 // 1/HZ. We check if clock_getres() works, but will ignore its reported 1246 // resolution for now. Hopefully as people move to new kernels, this 1247 // won't be a problem. 1248 struct timespec res; 1249 struct timespec tp; 1250 if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 && 1251 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) { 1252 // yes, monotonic clock is supported 1253 _clock_gettime = clock_gettime_func; 1254 return; 1255 } else { 1256 // close librt if there is no monotonic clock 1257 dlclose(handle); 1258 } 1259 } 1260 } 1261 warning("No monotonic clock was available - timed services may " \ 1262 "be adversely affected if the time-of-day clock changes"); 1263 } 1264 1265 #ifndef SYS_clock_getres 1266 #if defined(X86) || defined(PPC64) || defined(S390) 1267 #define SYS_clock_getres AMD64_ONLY(229) IA32_ONLY(266) PPC64_ONLY(247) S390_ONLY(261) 1268 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1269 #else 1270 #warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time" 1271 #define sys_clock_getres(x,y) -1 1272 #endif 1273 #else 1274 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1275 #endif 1276 1277 void os::Linux::fast_thread_clock_init() { 1278 if (!UseLinuxPosixThreadCPUClocks) { 1279 return; 1280 } 1281 clockid_t clockid; 1282 struct timespec tp; 1283 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) = 1284 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid"); 1285 1286 // Switch to using fast clocks for thread cpu time if 1287 // the sys_clock_getres() returns 0 error code. 1288 // Note, that some kernels may support the current thread 1289 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks 1290 // returned by the pthread_getcpuclockid(). 1291 // If the fast Posix clocks are supported then the sys_clock_getres() 1292 // must return at least tp.tv_sec == 0 which means a resolution 1293 // better than 1 sec. This is extra check for reliability. 1294 1295 if (pthread_getcpuclockid_func && 1296 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 && 1297 sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) { 1298 _supports_fast_thread_cpu_time = true; 1299 _pthread_getcpuclockid = pthread_getcpuclockid_func; 1300 } 1301 } 1302 1303 jlong os::javaTimeNanos() { 1304 if (os::supports_monotonic_clock()) { 1305 struct timespec tp; 1306 int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp); 1307 assert(status == 0, "gettime error"); 1308 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1309 return result; 1310 } else { 1311 timeval time; 1312 int status = gettimeofday(&time, NULL); 1313 assert(status != -1, "linux error"); 1314 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1315 return 1000 * usecs; 1316 } 1317 } 1318 1319 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1320 if (os::supports_monotonic_clock()) { 1321 info_ptr->max_value = ALL_64_BITS; 1322 1323 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1324 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1325 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1326 } else { 1327 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1328 info_ptr->max_value = ALL_64_BITS; 1329 1330 // gettimeofday is a real time clock so it skips 1331 info_ptr->may_skip_backward = true; 1332 info_ptr->may_skip_forward = true; 1333 } 1334 1335 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1336 } 1337 1338 // Return the real, user, and system times in seconds from an 1339 // arbitrary fixed point in the past. 1340 bool os::getTimesSecs(double* process_real_time, 1341 double* process_user_time, 1342 double* process_system_time) { 1343 struct tms ticks; 1344 clock_t real_ticks = times(&ticks); 1345 1346 if (real_ticks == (clock_t) (-1)) { 1347 return false; 1348 } else { 1349 double ticks_per_second = (double) clock_tics_per_sec; 1350 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1351 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1352 *process_real_time = ((double) real_ticks) / ticks_per_second; 1353 1354 return true; 1355 } 1356 } 1357 1358 1359 char * os::local_time_string(char *buf, size_t buflen) { 1360 struct tm t; 1361 time_t long_time; 1362 time(&long_time); 1363 localtime_r(&long_time, &t); 1364 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1365 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1366 t.tm_hour, t.tm_min, t.tm_sec); 1367 return buf; 1368 } 1369 1370 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1371 return localtime_r(clock, res); 1372 } 1373 1374 //////////////////////////////////////////////////////////////////////////////// 1375 // runtime exit support 1376 1377 // Note: os::shutdown() might be called very early during initialization, or 1378 // called from signal handler. Before adding something to os::shutdown(), make 1379 // sure it is async-safe and can handle partially initialized VM. 1380 void os::shutdown() { 1381 1382 // allow PerfMemory to attempt cleanup of any persistent resources 1383 perfMemory_exit(); 1384 1385 // needs to remove object in file system 1386 AttachListener::abort(); 1387 1388 // flush buffered output, finish log files 1389 ostream_abort(); 1390 1391 // Check for abort hook 1392 abort_hook_t abort_hook = Arguments::abort_hook(); 1393 if (abort_hook != NULL) { 1394 abort_hook(); 1395 } 1396 1397 } 1398 1399 // Note: os::abort() might be called very early during initialization, or 1400 // called from signal handler. Before adding something to os::abort(), make 1401 // sure it is async-safe and can handle partially initialized VM. 1402 void os::abort(bool dump_core, void* siginfo, const void* context) { 1403 os::shutdown(); 1404 if (dump_core) { 1405 #ifndef PRODUCT 1406 fdStream out(defaultStream::output_fd()); 1407 out.print_raw("Current thread is "); 1408 char buf[16]; 1409 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1410 out.print_raw_cr(buf); 1411 out.print_raw_cr("Dumping core ..."); 1412 #endif 1413 ::abort(); // dump core 1414 } 1415 1416 ::exit(1); 1417 } 1418 1419 // Die immediately, no exit hook, no abort hook, no cleanup. 1420 void os::die() { 1421 ::abort(); 1422 } 1423 1424 1425 // This method is a copy of JDK's sysGetLastErrorString 1426 // from src/solaris/hpi/src/system_md.c 1427 1428 size_t os::lasterror(char *buf, size_t len) { 1429 if (errno == 0) return 0; 1430 1431 const char *s = os::strerror(errno); 1432 size_t n = ::strlen(s); 1433 if (n >= len) { 1434 n = len - 1; 1435 } 1436 ::strncpy(buf, s, n); 1437 buf[n] = '\0'; 1438 return n; 1439 } 1440 1441 // thread_id is kernel thread id (similar to Solaris LWP id) 1442 intx os::current_thread_id() { return os::Linux::gettid(); } 1443 int os::current_process_id() { 1444 return ::getpid(); 1445 } 1446 1447 // DLL functions 1448 1449 const char* os::dll_file_extension() { return ".so"; } 1450 1451 // This must be hard coded because it's the system's temporary 1452 // directory not the java application's temp directory, ala java.io.tmpdir. 1453 const char* os::get_temp_directory() { return "/tmp"; } 1454 1455 static bool file_exists(const char* filename) { 1456 struct stat statbuf; 1457 if (filename == NULL || strlen(filename) == 0) { 1458 return false; 1459 } 1460 return os::stat(filename, &statbuf) == 0; 1461 } 1462 1463 // check if addr is inside libjvm.so 1464 bool os::address_is_in_vm(address addr) { 1465 static address libjvm_base_addr; 1466 Dl_info dlinfo; 1467 1468 if (libjvm_base_addr == NULL) { 1469 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1470 libjvm_base_addr = (address)dlinfo.dli_fbase; 1471 } 1472 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1473 } 1474 1475 if (dladdr((void *)addr, &dlinfo) != 0) { 1476 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1477 } 1478 1479 return false; 1480 } 1481 1482 bool os::dll_address_to_function_name(address addr, char *buf, 1483 int buflen, int *offset, 1484 bool demangle) { 1485 // buf is not optional, but offset is optional 1486 assert(buf != NULL, "sanity check"); 1487 1488 Dl_info dlinfo; 1489 1490 if (dladdr((void*)addr, &dlinfo) != 0) { 1491 // see if we have a matching symbol 1492 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1493 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) { 1494 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1495 } 1496 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1497 return true; 1498 } 1499 // no matching symbol so try for just file info 1500 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1501 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1502 buf, buflen, offset, dlinfo.dli_fname, demangle)) { 1503 return true; 1504 } 1505 } 1506 } 1507 1508 buf[0] = '\0'; 1509 if (offset != NULL) *offset = -1; 1510 return false; 1511 } 1512 1513 struct _address_to_library_name { 1514 address addr; // input : memory address 1515 size_t buflen; // size of fname 1516 char* fname; // output: library name 1517 address base; // library base addr 1518 }; 1519 1520 static int address_to_library_name_callback(struct dl_phdr_info *info, 1521 size_t size, void *data) { 1522 int i; 1523 bool found = false; 1524 address libbase = NULL; 1525 struct _address_to_library_name * d = (struct _address_to_library_name *)data; 1526 1527 // iterate through all loadable segments 1528 for (i = 0; i < info->dlpi_phnum; i++) { 1529 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); 1530 if (info->dlpi_phdr[i].p_type == PT_LOAD) { 1531 // base address of a library is the lowest address of its loaded 1532 // segments. 1533 if (libbase == NULL || libbase > segbase) { 1534 libbase = segbase; 1535 } 1536 // see if 'addr' is within current segment 1537 if (segbase <= d->addr && 1538 d->addr < segbase + info->dlpi_phdr[i].p_memsz) { 1539 found = true; 1540 } 1541 } 1542 } 1543 1544 // dlpi_name is NULL or empty if the ELF file is executable, return 0 1545 // so dll_address_to_library_name() can fall through to use dladdr() which 1546 // can figure out executable name from argv[0]. 1547 if (found && info->dlpi_name && info->dlpi_name[0]) { 1548 d->base = libbase; 1549 if (d->fname) { 1550 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); 1551 } 1552 return 1; 1553 } 1554 return 0; 1555 } 1556 1557 bool os::dll_address_to_library_name(address addr, char* buf, 1558 int buflen, int* offset) { 1559 // buf is not optional, but offset is optional 1560 assert(buf != NULL, "sanity check"); 1561 1562 Dl_info dlinfo; 1563 struct _address_to_library_name data; 1564 1565 // There is a bug in old glibc dladdr() implementation that it could resolve 1566 // to wrong library name if the .so file has a base address != NULL. Here 1567 // we iterate through the program headers of all loaded libraries to find 1568 // out which library 'addr' really belongs to. This workaround can be 1569 // removed once the minimum requirement for glibc is moved to 2.3.x. 1570 data.addr = addr; 1571 data.fname = buf; 1572 data.buflen = buflen; 1573 data.base = NULL; 1574 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); 1575 1576 if (rslt) { 1577 // buf already contains library name 1578 if (offset) *offset = addr - data.base; 1579 return true; 1580 } 1581 if (dladdr((void*)addr, &dlinfo) != 0) { 1582 if (dlinfo.dli_fname != NULL) { 1583 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1584 } 1585 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1586 *offset = addr - (address)dlinfo.dli_fbase; 1587 } 1588 return true; 1589 } 1590 1591 buf[0] = '\0'; 1592 if (offset) *offset = -1; 1593 return false; 1594 } 1595 1596 // Loads .dll/.so and 1597 // in case of error it checks if .dll/.so was built for the 1598 // same architecture as Hotspot is running on 1599 1600 1601 // Remember the stack's state. The Linux dynamic linker will change 1602 // the stack to 'executable' at most once, so we must safepoint only once. 1603 bool os::Linux::_stack_is_executable = false; 1604 1605 // VM operation that loads a library. This is necessary if stack protection 1606 // of the Java stacks can be lost during loading the library. If we 1607 // do not stop the Java threads, they can stack overflow before the stacks 1608 // are protected again. 1609 class VM_LinuxDllLoad: public VM_Operation { 1610 private: 1611 const char *_filename; 1612 char *_ebuf; 1613 int _ebuflen; 1614 void *_lib; 1615 public: 1616 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) : 1617 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {} 1618 VMOp_Type type() const { return VMOp_LinuxDllLoad; } 1619 void doit() { 1620 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen); 1621 os::Linux::_stack_is_executable = true; 1622 } 1623 void* loaded_library() { return _lib; } 1624 }; 1625 1626 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1627 void * result = NULL; 1628 bool load_attempted = false; 1629 1630 // Check whether the library to load might change execution rights 1631 // of the stack. If they are changed, the protection of the stack 1632 // guard pages will be lost. We need a safepoint to fix this. 1633 // 1634 // See Linux man page execstack(8) for more info. 1635 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) { 1636 if (!ElfFile::specifies_noexecstack(filename)) { 1637 if (!is_init_completed()) { 1638 os::Linux::_stack_is_executable = true; 1639 // This is OK - No Java threads have been created yet, and hence no 1640 // stack guard pages to fix. 1641 // 1642 // This should happen only when you are building JDK7 using a very 1643 // old version of JDK6 (e.g., with JPRT) and running test_gamma. 1644 // 1645 // Dynamic loader will make all stacks executable after 1646 // this function returns, and will not do that again. 1647 #ifdef ASSERT 1648 ThreadsListHandle tlh; 1649 assert(tlh.length() == 0, "no Java threads should exist yet."); 1650 #endif 1651 } else { 1652 warning("You have loaded library %s which might have disabled stack guard. " 1653 "The VM will try to fix the stack guard now.\n" 1654 "It's highly recommended that you fix the library with " 1655 "'execstack -c <libfile>', or link it with '-z noexecstack'.", 1656 filename); 1657 1658 assert(Thread::current()->is_Java_thread(), "must be Java thread"); 1659 JavaThread *jt = JavaThread::current(); 1660 if (jt->thread_state() != _thread_in_native) { 1661 // This happens when a compiler thread tries to load a hsdis-<arch>.so file 1662 // that requires ExecStack. Cannot enter safe point. Let's give up. 1663 warning("Unable to fix stack guard. Giving up."); 1664 } else { 1665 if (!LoadExecStackDllInVMThread) { 1666 // This is for the case where the DLL has an static 1667 // constructor function that executes JNI code. We cannot 1668 // load such DLLs in the VMThread. 1669 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1670 } 1671 1672 ThreadInVMfromNative tiv(jt); 1673 debug_only(VMNativeEntryWrapper vew;) 1674 1675 VM_LinuxDllLoad op(filename, ebuf, ebuflen); 1676 VMThread::execute(&op); 1677 if (LoadExecStackDllInVMThread) { 1678 result = op.loaded_library(); 1679 } 1680 load_attempted = true; 1681 } 1682 } 1683 } 1684 } 1685 1686 if (!load_attempted) { 1687 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1688 } 1689 1690 if (result != NULL) { 1691 // Successful loading 1692 return result; 1693 } 1694 1695 Elf32_Ehdr elf_head; 1696 int diag_msg_max_length=ebuflen-strlen(ebuf); 1697 char* diag_msg_buf=ebuf+strlen(ebuf); 1698 1699 if (diag_msg_max_length==0) { 1700 // No more space in ebuf for additional diagnostics message 1701 return NULL; 1702 } 1703 1704 1705 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1706 1707 if (file_descriptor < 0) { 1708 // Can't open library, report dlerror() message 1709 return NULL; 1710 } 1711 1712 bool failed_to_read_elf_head= 1713 (sizeof(elf_head)!= 1714 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1715 1716 ::close(file_descriptor); 1717 if (failed_to_read_elf_head) { 1718 // file i/o error - report dlerror() msg 1719 return NULL; 1720 } 1721 1722 typedef struct { 1723 Elf32_Half code; // Actual value as defined in elf.h 1724 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1725 unsigned char elf_class; // 32 or 64 bit 1726 unsigned char endianess; // MSB or LSB 1727 char* name; // String representation 1728 } arch_t; 1729 1730 #ifndef EM_486 1731 #define EM_486 6 /* Intel 80486 */ 1732 #endif 1733 #ifndef EM_AARCH64 1734 #define EM_AARCH64 183 /* ARM AARCH64 */ 1735 #endif 1736 #ifndef EM_RISCV 1737 #define EM_RISCV 243 1738 #endif 1739 1740 static const arch_t arch_array[]={ 1741 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1742 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1743 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1744 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1745 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1746 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1747 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1748 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1749 #if defined(VM_LITTLE_ENDIAN) 1750 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"}, 1751 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"}, 1752 #else 1753 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1754 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"}, 1755 #endif 1756 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1757 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1758 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1759 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1760 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1761 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1762 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}, 1763 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"}, 1764 {EM_RISCV, EM_RISCV, ELFCLASS64, ELFDATA2LSB, (char*)"RISCV"}, 1765 }; 1766 1767 #if (defined IA32) 1768 static Elf32_Half running_arch_code=EM_386; 1769 #elif (defined AMD64) 1770 static Elf32_Half running_arch_code=EM_X86_64; 1771 #elif (defined IA64) 1772 static Elf32_Half running_arch_code=EM_IA_64; 1773 #elif (defined __sparc) && (defined _LP64) 1774 static Elf32_Half running_arch_code=EM_SPARCV9; 1775 #elif (defined __sparc) && (!defined _LP64) 1776 static Elf32_Half running_arch_code=EM_SPARC; 1777 #elif (defined __powerpc64__) 1778 static Elf32_Half running_arch_code=EM_PPC64; 1779 #elif (defined __powerpc__) 1780 static Elf32_Half running_arch_code=EM_PPC; 1781 #elif (defined RISCV) 1782 static Elf32_Half running_arch_code=EM_RISCV; 1783 #elif (defined AARCH64) 1784 static Elf32_Half running_arch_code=EM_AARCH64; 1785 #elif (defined ARM) 1786 static Elf32_Half running_arch_code=EM_ARM; 1787 #elif (defined S390) 1788 static Elf32_Half running_arch_code=EM_S390; 1789 #elif (defined ALPHA) 1790 static Elf32_Half running_arch_code=EM_ALPHA; 1791 #elif (defined MIPSEL) 1792 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1793 #elif (defined PARISC) 1794 static Elf32_Half running_arch_code=EM_PARISC; 1795 #elif (defined MIPS) 1796 static Elf32_Half running_arch_code=EM_MIPS; 1797 #elif (defined M68K) 1798 static Elf32_Half running_arch_code=EM_68K; 1799 #elif (defined SH) 1800 static Elf32_Half running_arch_code=EM_SH; 1801 #else 1802 #error Method os::dll_load requires that one of following is defined:\ 1803 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc 1804 #endif 1805 1806 // Identify compatability class for VM's architecture and library's architecture 1807 // Obtain string descriptions for architectures 1808 1809 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1810 int running_arch_index=-1; 1811 1812 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1813 if (running_arch_code == arch_array[i].code) { 1814 running_arch_index = i; 1815 } 1816 if (lib_arch.code == arch_array[i].code) { 1817 lib_arch.compat_class = arch_array[i].compat_class; 1818 lib_arch.name = arch_array[i].name; 1819 } 1820 } 1821 1822 assert(running_arch_index != -1, 1823 "Didn't find running architecture code (running_arch_code) in arch_array"); 1824 if (running_arch_index == -1) { 1825 // Even though running architecture detection failed 1826 // we may still continue with reporting dlerror() message 1827 return NULL; 1828 } 1829 1830 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1831 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1832 return NULL; 1833 } 1834 1835 #ifndef S390 1836 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1837 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1838 return NULL; 1839 } 1840 #endif // !S390 1841 1842 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1843 if (lib_arch.name!=NULL) { 1844 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1845 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1846 lib_arch.name, arch_array[running_arch_index].name); 1847 } else { 1848 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1849 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1850 lib_arch.code, 1851 arch_array[running_arch_index].name); 1852 } 1853 } 1854 1855 return NULL; 1856 } 1857 1858 void * os::Linux::dlopen_helper(const char *filename, char *ebuf, 1859 int ebuflen) { 1860 void * result = ::dlopen(filename, RTLD_LAZY); 1861 if (result == NULL) { 1862 ::strncpy(ebuf, ::dlerror(), ebuflen - 1); 1863 ebuf[ebuflen-1] = '\0'; 1864 } 1865 return result; 1866 } 1867 1868 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf, 1869 int ebuflen) { 1870 void * result = NULL; 1871 if (LoadExecStackDllInVMThread) { 1872 result = dlopen_helper(filename, ebuf, ebuflen); 1873 } 1874 1875 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a 1876 // library that requires an executable stack, or which does not have this 1877 // stack attribute set, dlopen changes the stack attribute to executable. The 1878 // read protection of the guard pages gets lost. 1879 // 1880 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad 1881 // may have been queued at the same time. 1882 1883 if (!_stack_is_executable) { 1884 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) { 1885 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized 1886 jt->stack_guards_enabled()) { // No pending stack overflow exceptions 1887 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) { 1888 warning("Attempt to reguard stack yellow zone failed."); 1889 } 1890 } 1891 } 1892 } 1893 1894 return result; 1895 } 1896 1897 void* os::dll_lookup(void* handle, const char* name) { 1898 void* res = dlsym(handle, name); 1899 return res; 1900 } 1901 1902 void* os::get_default_process_handle() { 1903 return (void*)::dlopen(NULL, RTLD_LAZY); 1904 } 1905 1906 static bool _print_ascii_file(const char* filename, outputStream* st) { 1907 int fd = ::open(filename, O_RDONLY); 1908 if (fd == -1) { 1909 return false; 1910 } 1911 1912 char buf[33]; 1913 int bytes; 1914 buf[32] = '\0'; 1915 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) { 1916 st->print_raw(buf, bytes); 1917 } 1918 1919 ::close(fd); 1920 1921 return true; 1922 } 1923 1924 void os::print_dll_info(outputStream *st) { 1925 st->print_cr("Dynamic libraries:"); 1926 1927 char fname[32]; 1928 pid_t pid = os::Linux::gettid(); 1929 1930 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); 1931 1932 if (!_print_ascii_file(fname, st)) { 1933 st->print("Can not get library information for pid = %d\n", pid); 1934 } 1935 } 1936 1937 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1938 FILE *procmapsFile = NULL; 1939 1940 // Open the procfs maps file for the current process 1941 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) { 1942 // Allocate PATH_MAX for file name plus a reasonable size for other fields. 1943 char line[PATH_MAX + 100]; 1944 1945 // Read line by line from 'file' 1946 while (fgets(line, sizeof(line), procmapsFile) != NULL) { 1947 u8 base, top, offset, inode; 1948 char permissions[5]; 1949 char device[6]; 1950 char name[PATH_MAX + 1]; 1951 1952 // Parse fields from line 1953 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s", 1954 &base, &top, permissions, &offset, device, &inode, name); 1955 1956 // Filter by device id '00:00' so that we only get file system mapped files. 1957 if (strcmp(device, "00:00") != 0) { 1958 1959 // Call callback with the fields of interest 1960 if(callback(name, (address)base, (address)top, param)) { 1961 // Oops abort, callback aborted 1962 fclose(procmapsFile); 1963 return 1; 1964 } 1965 } 1966 } 1967 fclose(procmapsFile); 1968 } 1969 return 0; 1970 } 1971 1972 void os::print_os_info_brief(outputStream* st) { 1973 os::Linux::print_distro_info(st); 1974 1975 os::Posix::print_uname_info(st); 1976 1977 os::Linux::print_libversion_info(st); 1978 1979 } 1980 1981 void os::print_os_info(outputStream* st) { 1982 st->print("OS:"); 1983 1984 os::Linux::print_distro_info(st); 1985 1986 os::Posix::print_uname_info(st); 1987 1988 // Print warning if unsafe chroot environment detected 1989 if (unsafe_chroot_detected) { 1990 st->print("WARNING!! "); 1991 st->print_cr("%s", unstable_chroot_error); 1992 } 1993 1994 os::Linux::print_libversion_info(st); 1995 1996 os::Posix::print_rlimit_info(st); 1997 1998 os::Posix::print_load_average(st); 1999 2000 os::Linux::print_full_memory_info(st); 2001 2002 os::Linux::print_container_info(st); 2003 } 2004 2005 // Try to identify popular distros. 2006 // Most Linux distributions have a /etc/XXX-release file, which contains 2007 // the OS version string. Newer Linux distributions have a /etc/lsb-release 2008 // file that also contains the OS version string. Some have more than one 2009 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and 2010 // /etc/redhat-release.), so the order is important. 2011 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have 2012 // their own specific XXX-release file as well as a redhat-release file. 2013 // Because of this the XXX-release file needs to be searched for before the 2014 // redhat-release file. 2015 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the 2016 // search for redhat-release / SuSE-release needs to be before lsb-release. 2017 // Since the lsb-release file is the new standard it needs to be searched 2018 // before the older style release files. 2019 // Searching system-release (Red Hat) and os-release (other Linuxes) are a 2020 // next to last resort. The os-release file is a new standard that contains 2021 // distribution information and the system-release file seems to be an old 2022 // standard that has been replaced by the lsb-release and os-release files. 2023 // Searching for the debian_version file is the last resort. It contains 2024 // an informative string like "6.0.6" or "wheezy/sid". Because of this 2025 // "Debian " is printed before the contents of the debian_version file. 2026 2027 const char* distro_files[] = { 2028 "/etc/oracle-release", 2029 "/etc/mandriva-release", 2030 "/etc/mandrake-release", 2031 "/etc/sun-release", 2032 "/etc/redhat-release", 2033 "/etc/SuSE-release", 2034 "/etc/lsb-release", 2035 "/etc/turbolinux-release", 2036 "/etc/gentoo-release", 2037 "/etc/ltib-release", 2038 "/etc/angstrom-version", 2039 "/etc/system-release", 2040 "/etc/os-release", 2041 NULL }; 2042 2043 void os::Linux::print_distro_info(outputStream* st) { 2044 for (int i = 0;; i++) { 2045 const char* file = distro_files[i]; 2046 if (file == NULL) { 2047 break; // done 2048 } 2049 // If file prints, we found it. 2050 if (_print_ascii_file(file, st)) { 2051 return; 2052 } 2053 } 2054 2055 if (file_exists("/etc/debian_version")) { 2056 st->print("Debian "); 2057 _print_ascii_file("/etc/debian_version", st); 2058 } else { 2059 st->print("Linux"); 2060 } 2061 st->cr(); 2062 } 2063 2064 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) { 2065 char buf[256]; 2066 while (fgets(buf, sizeof(buf), fp)) { 2067 // Edit out extra stuff in expected format 2068 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) { 2069 char* ptr = strstr(buf, "\""); // the name is in quotes 2070 if (ptr != NULL) { 2071 ptr++; // go beyond first quote 2072 char* nl = strchr(ptr, '\"'); 2073 if (nl != NULL) *nl = '\0'; 2074 strncpy(distro, ptr, length); 2075 } else { 2076 ptr = strstr(buf, "="); 2077 ptr++; // go beyond equals then 2078 char* nl = strchr(ptr, '\n'); 2079 if (nl != NULL) *nl = '\0'; 2080 strncpy(distro, ptr, length); 2081 } 2082 return; 2083 } else if (get_first_line) { 2084 char* nl = strchr(buf, '\n'); 2085 if (nl != NULL) *nl = '\0'; 2086 strncpy(distro, buf, length); 2087 return; 2088 } 2089 } 2090 // print last line and close 2091 char* nl = strchr(buf, '\n'); 2092 if (nl != NULL) *nl = '\0'; 2093 strncpy(distro, buf, length); 2094 } 2095 2096 static void parse_os_info(char* distro, size_t length, const char* file) { 2097 FILE* fp = fopen(file, "r"); 2098 if (fp != NULL) { 2099 // if suse format, print out first line 2100 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0); 2101 parse_os_info_helper(fp, distro, length, get_first_line); 2102 fclose(fp); 2103 } 2104 } 2105 2106 void os::get_summary_os_info(char* buf, size_t buflen) { 2107 for (int i = 0;; i++) { 2108 const char* file = distro_files[i]; 2109 if (file == NULL) { 2110 break; // ran out of distro_files 2111 } 2112 if (file_exists(file)) { 2113 parse_os_info(buf, buflen, file); 2114 return; 2115 } 2116 } 2117 // special case for debian 2118 if (file_exists("/etc/debian_version")) { 2119 strncpy(buf, "Debian ", buflen); 2120 parse_os_info(&buf[7], buflen-7, "/etc/debian_version"); 2121 } else { 2122 strncpy(buf, "Linux", buflen); 2123 } 2124 } 2125 2126 void os::Linux::print_libversion_info(outputStream* st) { 2127 // libc, pthread 2128 st->print("libc:"); 2129 st->print("%s ", os::Linux::glibc_version()); 2130 st->print("%s ", os::Linux::libpthread_version()); 2131 st->cr(); 2132 } 2133 2134 void os::Linux::print_full_memory_info(outputStream* st) { 2135 st->print("\n/proc/meminfo:\n"); 2136 _print_ascii_file("/proc/meminfo", st); 2137 st->cr(); 2138 } 2139 2140 void os::Linux::print_container_info(outputStream* st) { 2141 if (!OSContainer::is_containerized()) { 2142 return; 2143 } 2144 2145 st->print("container (cgroup) information:\n"); 2146 2147 const char *p_ct = OSContainer::container_type(); 2148 st->print("container_type: %s\n", p_ct != NULL ? p_ct : "failed"); 2149 2150 char *p = OSContainer::cpu_cpuset_cpus(); 2151 st->print("cpu_cpuset_cpus: %s\n", p != NULL ? p : "failed"); 2152 free(p); 2153 2154 p = OSContainer::cpu_cpuset_memory_nodes(); 2155 st->print("cpu_memory_nodes: %s\n", p != NULL ? p : "failed"); 2156 free(p); 2157 2158 int i = OSContainer::active_processor_count(); 2159 if (i > 0) { 2160 st->print("active_processor_count: %d\n", i); 2161 } else { 2162 st->print("active_processor_count: failed\n"); 2163 } 2164 2165 i = OSContainer::cpu_quota(); 2166 st->print("cpu_quota: %d\n", i); 2167 2168 i = OSContainer::cpu_period(); 2169 st->print("cpu_period: %d\n", i); 2170 2171 i = OSContainer::cpu_shares(); 2172 st->print("cpu_shares: %d\n", i); 2173 2174 jlong j = OSContainer::memory_limit_in_bytes(); 2175 st->print("memory_limit_in_bytes: " JLONG_FORMAT "\n", j); 2176 2177 j = OSContainer::memory_and_swap_limit_in_bytes(); 2178 st->print("memory_and_swap_limit_in_bytes: " JLONG_FORMAT "\n", j); 2179 2180 j = OSContainer::memory_soft_limit_in_bytes(); 2181 st->print("memory_soft_limit_in_bytes: " JLONG_FORMAT "\n", j); 2182 2183 j = OSContainer::OSContainer::memory_usage_in_bytes(); 2184 st->print("memory_usage_in_bytes: " JLONG_FORMAT "\n", j); 2185 2186 j = OSContainer::OSContainer::memory_max_usage_in_bytes(); 2187 st->print("memory_max_usage_in_bytes: " JLONG_FORMAT "\n", j); 2188 st->cr(); 2189 } 2190 2191 void os::print_memory_info(outputStream* st) { 2192 2193 st->print("Memory:"); 2194 st->print(" %dk page", os::vm_page_size()>>10); 2195 2196 // values in struct sysinfo are "unsigned long" 2197 struct sysinfo si; 2198 sysinfo(&si); 2199 2200 st->print(", physical " UINT64_FORMAT "k", 2201 os::physical_memory() >> 10); 2202 st->print("(" UINT64_FORMAT "k free)", 2203 os::available_memory() >> 10); 2204 st->print(", swap " UINT64_FORMAT "k", 2205 ((jlong)si.totalswap * si.mem_unit) >> 10); 2206 st->print("(" UINT64_FORMAT "k free)", 2207 ((jlong)si.freeswap * si.mem_unit) >> 10); 2208 st->cr(); 2209 } 2210 2211 // Print the first "model name" line and the first "flags" line 2212 // that we find and nothing more. We assume "model name" comes 2213 // before "flags" so if we find a second "model name", then the 2214 // "flags" field is considered missing. 2215 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) { 2216 #if defined(IA32) || defined(AMD64) 2217 // Other platforms have less repetitive cpuinfo files 2218 FILE *fp = fopen("/proc/cpuinfo", "r"); 2219 if (fp) { 2220 while (!feof(fp)) { 2221 if (fgets(buf, buflen, fp)) { 2222 // Assume model name comes before flags 2223 bool model_name_printed = false; 2224 if (strstr(buf, "model name") != NULL) { 2225 if (!model_name_printed) { 2226 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n"); 2227 st->print_raw(buf); 2228 model_name_printed = true; 2229 } else { 2230 // model name printed but not flags? Odd, just return 2231 fclose(fp); 2232 return true; 2233 } 2234 } 2235 // print the flags line too 2236 if (strstr(buf, "flags") != NULL) { 2237 st->print_raw(buf); 2238 fclose(fp); 2239 return true; 2240 } 2241 } 2242 } 2243 fclose(fp); 2244 } 2245 #endif // x86 platforms 2246 return false; 2247 } 2248 2249 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) { 2250 // Only print the model name if the platform provides this as a summary 2251 if (!print_model_name_and_flags(st, buf, buflen)) { 2252 st->print("\n/proc/cpuinfo:\n"); 2253 if (!_print_ascii_file("/proc/cpuinfo", st)) { 2254 st->print_cr(" <Not Available>"); 2255 } 2256 } 2257 } 2258 2259 #if defined(AMD64) || defined(IA32) || defined(X32) 2260 const char* search_string = "model name"; 2261 #elif defined(M68K) 2262 const char* search_string = "CPU"; 2263 #elif defined(PPC64) 2264 const char* search_string = "cpu"; 2265 #elif defined(S390) 2266 const char* search_string = "processor"; 2267 #elif defined(SPARC) 2268 const char* search_string = "cpu"; 2269 #else 2270 const char* search_string = "Processor"; 2271 #endif 2272 2273 // Parses the cpuinfo file for string representing the model name. 2274 void os::get_summary_cpu_info(char* cpuinfo, size_t length) { 2275 FILE* fp = fopen("/proc/cpuinfo", "r"); 2276 if (fp != NULL) { 2277 while (!feof(fp)) { 2278 char buf[256]; 2279 if (fgets(buf, sizeof(buf), fp)) { 2280 char* start = strstr(buf, search_string); 2281 if (start != NULL) { 2282 char *ptr = start + strlen(search_string); 2283 char *end = buf + strlen(buf); 2284 while (ptr != end) { 2285 // skip whitespace and colon for the rest of the name. 2286 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') { 2287 break; 2288 } 2289 ptr++; 2290 } 2291 if (ptr != end) { 2292 // reasonable string, get rid of newline and keep the rest 2293 char* nl = strchr(buf, '\n'); 2294 if (nl != NULL) *nl = '\0'; 2295 strncpy(cpuinfo, ptr, length); 2296 fclose(fp); 2297 return; 2298 } 2299 } 2300 } 2301 } 2302 fclose(fp); 2303 } 2304 // cpuinfo not found or parsing failed, just print generic string. The entire 2305 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86) 2306 #if defined(AARCH64) 2307 strncpy(cpuinfo, "AArch64", length); 2308 #elif defined(AMD64) 2309 strncpy(cpuinfo, "x86_64", length); 2310 #elif defined(ARM) // Order wrt. AARCH64 is relevant! 2311 strncpy(cpuinfo, "ARM", length); 2312 #elif defined(IA32) 2313 strncpy(cpuinfo, "x86_32", length); 2314 #elif defined(IA64) 2315 strncpy(cpuinfo, "IA64", length); 2316 #elif defined(PPC) 2317 strncpy(cpuinfo, "PPC64", length); 2318 #elif defined(RISCV) 2319 strncpy(cpuinfo, "RISCV", length); 2320 #elif defined(S390) 2321 strncpy(cpuinfo, "S390", length); 2322 #elif defined(SPARC) 2323 strncpy(cpuinfo, "sparcv9", length); 2324 #elif defined(ZERO_LIBARCH) 2325 strncpy(cpuinfo, ZERO_LIBARCH, length); 2326 #else 2327 strncpy(cpuinfo, "unknown", length); 2328 #endif 2329 } 2330 2331 static void print_signal_handler(outputStream* st, int sig, 2332 char* buf, size_t buflen); 2333 2334 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 2335 st->print_cr("Signal Handlers:"); 2336 print_signal_handler(st, SIGSEGV, buf, buflen); 2337 print_signal_handler(st, SIGBUS , buf, buflen); 2338 print_signal_handler(st, SIGFPE , buf, buflen); 2339 print_signal_handler(st, SIGPIPE, buf, buflen); 2340 print_signal_handler(st, SIGXFSZ, buf, buflen); 2341 print_signal_handler(st, SIGILL , buf, buflen); 2342 print_signal_handler(st, SR_signum, buf, buflen); 2343 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 2344 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 2345 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 2346 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 2347 #if defined(PPC64) 2348 print_signal_handler(st, SIGTRAP, buf, buflen); 2349 #endif 2350 } 2351 2352 static char saved_jvm_path[MAXPATHLEN] = {0}; 2353 2354 // Find the full path to the current module, libjvm.so 2355 void os::jvm_path(char *buf, jint buflen) { 2356 // Error checking. 2357 if (buflen < MAXPATHLEN) { 2358 assert(false, "must use a large-enough buffer"); 2359 buf[0] = '\0'; 2360 return; 2361 } 2362 // Lazy resolve the path to current module. 2363 if (saved_jvm_path[0] != 0) { 2364 strcpy(buf, saved_jvm_path); 2365 return; 2366 } 2367 2368 char dli_fname[MAXPATHLEN]; 2369 bool ret = dll_address_to_library_name( 2370 CAST_FROM_FN_PTR(address, os::jvm_path), 2371 dli_fname, sizeof(dli_fname), NULL); 2372 assert(ret, "cannot locate libjvm"); 2373 char *rp = NULL; 2374 if (ret && dli_fname[0] != '\0') { 2375 rp = os::Posix::realpath(dli_fname, buf, buflen); 2376 } 2377 if (rp == NULL) { 2378 return; 2379 } 2380 2381 if (Arguments::sun_java_launcher_is_altjvm()) { 2382 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 2383 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so". 2384 // If "/jre/lib/" appears at the right place in the string, then 2385 // assume we are installed in a JDK and we're done. Otherwise, check 2386 // for a JAVA_HOME environment variable and fix up the path so it 2387 // looks like libjvm.so is installed there (append a fake suffix 2388 // hotspot/libjvm.so). 2389 const char *p = buf + strlen(buf) - 1; 2390 for (int count = 0; p > buf && count < 5; ++count) { 2391 for (--p; p > buf && *p != '/'; --p) 2392 /* empty */ ; 2393 } 2394 2395 if (strncmp(p, "/jre/lib/", 9) != 0) { 2396 // Look for JAVA_HOME in the environment. 2397 char* java_home_var = ::getenv("JAVA_HOME"); 2398 if (java_home_var != NULL && java_home_var[0] != 0) { 2399 char* jrelib_p; 2400 int len; 2401 2402 // Check the current module name "libjvm.so". 2403 p = strrchr(buf, '/'); 2404 if (p == NULL) { 2405 return; 2406 } 2407 assert(strstr(p, "/libjvm") == p, "invalid library name"); 2408 2409 rp = os::Posix::realpath(java_home_var, buf, buflen); 2410 if (rp == NULL) { 2411 return; 2412 } 2413 2414 // determine if this is a legacy image or modules image 2415 // modules image doesn't have "jre" subdirectory 2416 len = strlen(buf); 2417 assert(len < buflen, "Ran out of buffer room"); 2418 jrelib_p = buf + len; 2419 snprintf(jrelib_p, buflen-len, "/jre/lib"); 2420 if (0 != access(buf, F_OK)) { 2421 snprintf(jrelib_p, buflen-len, "/lib"); 2422 } 2423 2424 if (0 == access(buf, F_OK)) { 2425 // Use current module name "libjvm.so" 2426 len = strlen(buf); 2427 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so"); 2428 } else { 2429 // Go back to path of .so 2430 rp = os::Posix::realpath(dli_fname, buf, buflen); 2431 if (rp == NULL) { 2432 return; 2433 } 2434 } 2435 } 2436 } 2437 } 2438 2439 strncpy(saved_jvm_path, buf, MAXPATHLEN); 2440 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 2441 } 2442 2443 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 2444 // no prefix required, not even "_" 2445 } 2446 2447 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 2448 // no suffix required 2449 } 2450 2451 //////////////////////////////////////////////////////////////////////////////// 2452 // sun.misc.Signal support 2453 2454 static volatile jint sigint_count = 0; 2455 2456 static void UserHandler(int sig, void *siginfo, void *context) { 2457 // 4511530 - sem_post is serialized and handled by the manager thread. When 2458 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 2459 // don't want to flood the manager thread with sem_post requests. 2460 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 2461 return; 2462 } 2463 2464 // Ctrl-C is pressed during error reporting, likely because the error 2465 // handler fails to abort. Let VM die immediately. 2466 if (sig == SIGINT && VMError::is_error_reported()) { 2467 os::die(); 2468 } 2469 2470 os::signal_notify(sig); 2471 } 2472 2473 void* os::user_handler() { 2474 return CAST_FROM_FN_PTR(void*, UserHandler); 2475 } 2476 2477 static struct timespec create_semaphore_timespec(unsigned int sec, int nsec) { 2478 struct timespec ts; 2479 // Semaphore's are always associated with CLOCK_REALTIME 2480 os::Linux::clock_gettime(CLOCK_REALTIME, &ts); 2481 // see os_posix.cpp for discussion on overflow checking 2482 if (sec >= MAX_SECS) { 2483 ts.tv_sec += MAX_SECS; 2484 ts.tv_nsec = 0; 2485 } else { 2486 ts.tv_sec += sec; 2487 ts.tv_nsec += nsec; 2488 if (ts.tv_nsec >= NANOSECS_PER_SEC) { 2489 ts.tv_nsec -= NANOSECS_PER_SEC; 2490 ++ts.tv_sec; // note: this must be <= max_secs 2491 } 2492 } 2493 2494 return ts; 2495 } 2496 2497 extern "C" { 2498 typedef void (*sa_handler_t)(int); 2499 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 2500 } 2501 2502 void* os::signal(int signal_number, void* handler) { 2503 struct sigaction sigAct, oldSigAct; 2504 2505 sigfillset(&(sigAct.sa_mask)); 2506 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 2507 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 2508 2509 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 2510 // -1 means registration failed 2511 return (void *)-1; 2512 } 2513 2514 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 2515 } 2516 2517 void os::signal_raise(int signal_number) { 2518 ::raise(signal_number); 2519 } 2520 2521 // The following code is moved from os.cpp for making this 2522 // code platform specific, which it is by its very nature. 2523 2524 // Will be modified when max signal is changed to be dynamic 2525 int os::sigexitnum_pd() { 2526 return NSIG; 2527 } 2528 2529 // a counter for each possible signal value 2530 static volatile jint pending_signals[NSIG+1] = { 0 }; 2531 2532 // Linux(POSIX) specific hand shaking semaphore. 2533 static Semaphore* sig_sem = NULL; 2534 static PosixSemaphore sr_semaphore; 2535 2536 void os::signal_init_pd() { 2537 // Initialize signal structures 2538 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2539 2540 // Initialize signal semaphore 2541 sig_sem = new Semaphore(); 2542 } 2543 2544 void os::signal_notify(int sig) { 2545 if (sig_sem != NULL) { 2546 Atomic::inc(&pending_signals[sig]); 2547 sig_sem->signal(); 2548 } else { 2549 // Signal thread is not created with ReduceSignalUsage and signal_init_pd 2550 // initialization isn't called. 2551 assert(ReduceSignalUsage, "signal semaphore should be created"); 2552 } 2553 } 2554 2555 static int check_pending_signals() { 2556 Atomic::store(0, &sigint_count); 2557 for (;;) { 2558 for (int i = 0; i < NSIG + 1; i++) { 2559 jint n = pending_signals[i]; 2560 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2561 return i; 2562 } 2563 } 2564 JavaThread *thread = JavaThread::current(); 2565 ThreadBlockInVM tbivm(thread); 2566 2567 bool threadIsSuspended; 2568 do { 2569 thread->set_suspend_equivalent(); 2570 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2571 sig_sem->wait(); 2572 2573 // were we externally suspended while we were waiting? 2574 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2575 if (threadIsSuspended) { 2576 // The semaphore has been incremented, but while we were waiting 2577 // another thread suspended us. We don't want to continue running 2578 // while suspended because that would surprise the thread that 2579 // suspended us. 2580 sig_sem->signal(); 2581 2582 thread->java_suspend_self(); 2583 } 2584 } while (threadIsSuspended); 2585 } 2586 } 2587 2588 int os::signal_wait() { 2589 return check_pending_signals(); 2590 } 2591 2592 //////////////////////////////////////////////////////////////////////////////// 2593 // Virtual Memory 2594 2595 int os::vm_page_size() { 2596 // Seems redundant as all get out 2597 assert(os::Linux::page_size() != -1, "must call os::init"); 2598 return os::Linux::page_size(); 2599 } 2600 2601 // Solaris allocates memory by pages. 2602 int os::vm_allocation_granularity() { 2603 assert(os::Linux::page_size() != -1, "must call os::init"); 2604 return os::Linux::page_size(); 2605 } 2606 2607 // Rationale behind this function: 2608 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2609 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2610 // samples for JITted code. Here we create private executable mapping over the code cache 2611 // and then we can use standard (well, almost, as mapping can change) way to provide 2612 // info for the reporting script by storing timestamp and location of symbol 2613 void linux_wrap_code(char* base, size_t size) { 2614 static volatile jint cnt = 0; 2615 2616 if (!UseOprofile) { 2617 return; 2618 } 2619 2620 char buf[PATH_MAX+1]; 2621 int num = Atomic::add(1, &cnt); 2622 2623 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d", 2624 os::get_temp_directory(), os::current_process_id(), num); 2625 unlink(buf); 2626 2627 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2628 2629 if (fd != -1) { 2630 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2631 if (rv != (off_t)-1) { 2632 if (::write(fd, "", 1) == 1) { 2633 mmap(base, size, 2634 PROT_READ|PROT_WRITE|PROT_EXEC, 2635 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2636 } 2637 } 2638 ::close(fd); 2639 unlink(buf); 2640 } 2641 } 2642 2643 static bool recoverable_mmap_error(int err) { 2644 // See if the error is one we can let the caller handle. This 2645 // list of errno values comes from JBS-6843484. I can't find a 2646 // Linux man page that documents this specific set of errno 2647 // values so while this list currently matches Solaris, it may 2648 // change as we gain experience with this failure mode. 2649 switch (err) { 2650 case EBADF: 2651 case EINVAL: 2652 case ENOTSUP: 2653 // let the caller deal with these errors 2654 return true; 2655 2656 default: 2657 // Any remaining errors on this OS can cause our reserved mapping 2658 // to be lost. That can cause confusion where different data 2659 // structures think they have the same memory mapped. The worst 2660 // scenario is if both the VM and a library think they have the 2661 // same memory mapped. 2662 return false; 2663 } 2664 } 2665 2666 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2667 int err) { 2668 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2669 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec, 2670 os::strerror(err), err); 2671 } 2672 2673 static void warn_fail_commit_memory(char* addr, size_t size, 2674 size_t alignment_hint, bool exec, 2675 int err) { 2676 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2677 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, 2678 alignment_hint, exec, os::strerror(err), err); 2679 } 2680 2681 // NOTE: Linux kernel does not really reserve the pages for us. 2682 // All it does is to check if there are enough free pages 2683 // left at the time of mmap(). This could be a potential 2684 // problem. 2685 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) { 2686 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2687 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2688 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2689 if (res != (uintptr_t) MAP_FAILED) { 2690 if (UseNUMAInterleaving) { 2691 numa_make_global(addr, size); 2692 } 2693 return 0; 2694 } 2695 2696 int err = errno; // save errno from mmap() call above 2697 2698 if (!recoverable_mmap_error(err)) { 2699 warn_fail_commit_memory(addr, size, exec, err); 2700 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory."); 2701 } 2702 2703 return err; 2704 } 2705 2706 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2707 return os::Linux::commit_memory_impl(addr, size, exec) == 0; 2708 } 2709 2710 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2711 const char* mesg) { 2712 assert(mesg != NULL, "mesg must be specified"); 2713 int err = os::Linux::commit_memory_impl(addr, size, exec); 2714 if (err != 0) { 2715 // the caller wants all commit errors to exit with the specified mesg: 2716 warn_fail_commit_memory(addr, size, exec, err); 2717 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2718 } 2719 } 2720 2721 // Define MAP_HUGETLB here so we can build HotSpot on old systems. 2722 #ifndef MAP_HUGETLB 2723 #define MAP_HUGETLB 0x40000 2724 #endif 2725 2726 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems. 2727 #ifndef MADV_HUGEPAGE 2728 #define MADV_HUGEPAGE 14 2729 #endif 2730 2731 int os::Linux::commit_memory_impl(char* addr, size_t size, 2732 size_t alignment_hint, bool exec) { 2733 int err = os::Linux::commit_memory_impl(addr, size, exec); 2734 if (err == 0) { 2735 realign_memory(addr, size, alignment_hint); 2736 } 2737 return err; 2738 } 2739 2740 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2741 bool exec) { 2742 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0; 2743 } 2744 2745 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2746 size_t alignment_hint, bool exec, 2747 const char* mesg) { 2748 assert(mesg != NULL, "mesg must be specified"); 2749 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec); 2750 if (err != 0) { 2751 // the caller wants all commit errors to exit with the specified mesg: 2752 warn_fail_commit_memory(addr, size, alignment_hint, exec, err); 2753 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2754 } 2755 } 2756 2757 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2758 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) { 2759 // We don't check the return value: madvise(MADV_HUGEPAGE) may not 2760 // be supported or the memory may already be backed by huge pages. 2761 ::madvise(addr, bytes, MADV_HUGEPAGE); 2762 } 2763 } 2764 2765 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2766 // This method works by doing an mmap over an existing mmaping and effectively discarding 2767 // the existing pages. However it won't work for SHM-based large pages that cannot be 2768 // uncommitted at all. We don't do anything in this case to avoid creating a segment with 2769 // small pages on top of the SHM segment. This method always works for small pages, so we 2770 // allow that in any case. 2771 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) { 2772 commit_memory(addr, bytes, alignment_hint, !ExecMem); 2773 } 2774 } 2775 2776 void os::numa_make_global(char *addr, size_t bytes) { 2777 Linux::numa_interleave_memory(addr, bytes); 2778 } 2779 2780 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the 2781 // bind policy to MPOL_PREFERRED for the current thread. 2782 #define USE_MPOL_PREFERRED 0 2783 2784 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2785 // To make NUMA and large pages more robust when both enabled, we need to ease 2786 // the requirements on where the memory should be allocated. MPOL_BIND is the 2787 // default policy and it will force memory to be allocated on the specified 2788 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on 2789 // the specified node, but will not force it. Using this policy will prevent 2790 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no 2791 // free large pages. 2792 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED); 2793 Linux::numa_tonode_memory(addr, bytes, lgrp_hint); 2794 } 2795 2796 bool os::numa_topology_changed() { return false; } 2797 2798 size_t os::numa_get_groups_num() { 2799 // Return just the number of nodes in which it's possible to allocate memory 2800 // (in numa terminology, configured nodes). 2801 return Linux::numa_num_configured_nodes(); 2802 } 2803 2804 int os::numa_get_group_id() { 2805 int cpu_id = Linux::sched_getcpu(); 2806 if (cpu_id != -1) { 2807 int lgrp_id = Linux::get_node_by_cpu(cpu_id); 2808 if (lgrp_id != -1) { 2809 return lgrp_id; 2810 } 2811 } 2812 return 0; 2813 } 2814 2815 int os::Linux::get_existing_num_nodes() { 2816 size_t node; 2817 size_t highest_node_number = Linux::numa_max_node(); 2818 int num_nodes = 0; 2819 2820 // Get the total number of nodes in the system including nodes without memory. 2821 for (node = 0; node <= highest_node_number; node++) { 2822 if (isnode_in_existing_nodes(node)) { 2823 num_nodes++; 2824 } 2825 } 2826 return num_nodes; 2827 } 2828 2829 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2830 size_t highest_node_number = Linux::numa_max_node(); 2831 size_t i = 0; 2832 2833 // Map all node ids in which is possible to allocate memory. Also nodes are 2834 // not always consecutively available, i.e. available from 0 to the highest 2835 // node number. 2836 for (size_t node = 0; node <= highest_node_number; node++) { 2837 if (Linux::isnode_in_configured_nodes(node)) { 2838 ids[i++] = node; 2839 } 2840 } 2841 return i; 2842 } 2843 2844 bool os::get_page_info(char *start, page_info* info) { 2845 return false; 2846 } 2847 2848 char *os::scan_pages(char *start, char* end, page_info* page_expected, 2849 page_info* page_found) { 2850 return end; 2851 } 2852 2853 2854 int os::Linux::sched_getcpu_syscall(void) { 2855 unsigned int cpu = 0; 2856 int retval = -1; 2857 2858 #if defined(IA32) 2859 #ifndef SYS_getcpu 2860 #define SYS_getcpu 318 2861 #endif 2862 retval = syscall(SYS_getcpu, &cpu, NULL, NULL); 2863 #elif defined(AMD64) 2864 // Unfortunately we have to bring all these macros here from vsyscall.h 2865 // to be able to compile on old linuxes. 2866 #define __NR_vgetcpu 2 2867 #define VSYSCALL_START (-10UL << 20) 2868 #define VSYSCALL_SIZE 1024 2869 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr)) 2870 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache); 2871 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu); 2872 retval = vgetcpu(&cpu, NULL, NULL); 2873 #endif 2874 2875 return (retval == -1) ? retval : cpu; 2876 } 2877 2878 void os::Linux::sched_getcpu_init() { 2879 // sched_getcpu() should be in libc. 2880 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2881 dlsym(RTLD_DEFAULT, "sched_getcpu"))); 2882 2883 // If it's not, try a direct syscall. 2884 if (sched_getcpu() == -1) { 2885 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2886 (void*)&sched_getcpu_syscall)); 2887 } 2888 } 2889 2890 // Something to do with the numa-aware allocator needs these symbols 2891 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { } 2892 extern "C" JNIEXPORT void numa_error(char *where) { } 2893 2894 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails 2895 // load symbol from base version instead. 2896 void* os::Linux::libnuma_dlsym(void* handle, const char *name) { 2897 void *f = dlvsym(handle, name, "libnuma_1.1"); 2898 if (f == NULL) { 2899 f = dlsym(handle, name); 2900 } 2901 return f; 2902 } 2903 2904 // Handle request to load libnuma symbol version 1.2 (API v2) only. 2905 // Return NULL if the symbol is not defined in this particular version. 2906 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) { 2907 return dlvsym(handle, name, "libnuma_1.2"); 2908 } 2909 2910 bool os::Linux::libnuma_init() { 2911 if (sched_getcpu() != -1) { // Requires sched_getcpu() support 2912 void *handle = dlopen("libnuma.so.1", RTLD_LAZY); 2913 if (handle != NULL) { 2914 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, 2915 libnuma_dlsym(handle, "numa_node_to_cpus"))); 2916 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, 2917 libnuma_dlsym(handle, "numa_max_node"))); 2918 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t, 2919 libnuma_dlsym(handle, "numa_num_configured_nodes"))); 2920 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, 2921 libnuma_dlsym(handle, "numa_available"))); 2922 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, 2923 libnuma_dlsym(handle, "numa_tonode_memory"))); 2924 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t, 2925 libnuma_dlsym(handle, "numa_interleave_memory"))); 2926 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t, 2927 libnuma_v2_dlsym(handle, "numa_interleave_memory"))); 2928 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t, 2929 libnuma_dlsym(handle, "numa_set_bind_policy"))); 2930 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t, 2931 libnuma_dlsym(handle, "numa_bitmask_isbitset"))); 2932 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t, 2933 libnuma_dlsym(handle, "numa_distance"))); 2934 2935 if (numa_available() != -1) { 2936 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); 2937 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr")); 2938 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr")); 2939 // Create an index -> node mapping, since nodes are not always consecutive 2940 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2941 rebuild_nindex_to_node_map(); 2942 // Create a cpu -> node mapping 2943 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2944 rebuild_cpu_to_node_map(); 2945 return true; 2946 } 2947 } 2948 } 2949 return false; 2950 } 2951 2952 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 2953 // Creating guard page is very expensive. Java thread has HotSpot 2954 // guard pages, only enable glibc guard page for non-Java threads. 2955 // (Remember: compiler thread is a Java thread, too!) 2956 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size()); 2957 } 2958 2959 void os::Linux::rebuild_nindex_to_node_map() { 2960 int highest_node_number = Linux::numa_max_node(); 2961 2962 nindex_to_node()->clear(); 2963 for (int node = 0; node <= highest_node_number; node++) { 2964 if (Linux::isnode_in_existing_nodes(node)) { 2965 nindex_to_node()->append(node); 2966 } 2967 } 2968 } 2969 2970 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. 2971 // The table is later used in get_node_by_cpu(). 2972 void os::Linux::rebuild_cpu_to_node_map() { 2973 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure 2974 // in libnuma (possible values are starting from 16, 2975 // and continuing up with every other power of 2, but less 2976 // than the maximum number of CPUs supported by kernel), and 2977 // is a subject to change (in libnuma version 2 the requirements 2978 // are more reasonable) we'll just hardcode the number they use 2979 // in the library. 2980 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT; 2981 2982 size_t cpu_num = processor_count(); 2983 size_t cpu_map_size = NCPUS / BitsPerCLong; 2984 size_t cpu_map_valid_size = 2985 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size); 2986 2987 cpu_to_node()->clear(); 2988 cpu_to_node()->at_grow(cpu_num - 1); 2989 2990 size_t node_num = get_existing_num_nodes(); 2991 2992 int distance = 0; 2993 int closest_distance = INT_MAX; 2994 int closest_node = 0; 2995 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal); 2996 for (size_t i = 0; i < node_num; i++) { 2997 // Check if node is configured (not a memory-less node). If it is not, find 2998 // the closest configured node. 2999 if (!isnode_in_configured_nodes(nindex_to_node()->at(i))) { 3000 closest_distance = INT_MAX; 3001 // Check distance from all remaining nodes in the system. Ignore distance 3002 // from itself and from another non-configured node. 3003 for (size_t m = 0; m < node_num; m++) { 3004 if (m != i && isnode_in_configured_nodes(nindex_to_node()->at(m))) { 3005 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m)); 3006 // If a closest node is found, update. There is always at least one 3007 // configured node in the system so there is always at least one node 3008 // close. 3009 if (distance != 0 && distance < closest_distance) { 3010 closest_distance = distance; 3011 closest_node = nindex_to_node()->at(m); 3012 } 3013 } 3014 } 3015 } else { 3016 // Current node is already a configured node. 3017 closest_node = nindex_to_node()->at(i); 3018 } 3019 3020 // Get cpus from the original node and map them to the closest node. If node 3021 // is a configured node (not a memory-less node), then original node and 3022 // closest node are the same. 3023 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { 3024 for (size_t j = 0; j < cpu_map_valid_size; j++) { 3025 if (cpu_map[j] != 0) { 3026 for (size_t k = 0; k < BitsPerCLong; k++) { 3027 if (cpu_map[j] & (1UL << k)) { 3028 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node); 3029 } 3030 } 3031 } 3032 } 3033 } 3034 } 3035 FREE_C_HEAP_ARRAY(unsigned long, cpu_map); 3036 } 3037 3038 int os::Linux::get_node_by_cpu(int cpu_id) { 3039 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { 3040 return cpu_to_node()->at(cpu_id); 3041 } 3042 return -1; 3043 } 3044 3045 GrowableArray<int>* os::Linux::_cpu_to_node; 3046 GrowableArray<int>* os::Linux::_nindex_to_node; 3047 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu; 3048 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus; 3049 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node; 3050 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes; 3051 os::Linux::numa_available_func_t os::Linux::_numa_available; 3052 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory; 3053 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory; 3054 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2; 3055 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy; 3056 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset; 3057 os::Linux::numa_distance_func_t os::Linux::_numa_distance; 3058 unsigned long* os::Linux::_numa_all_nodes; 3059 struct bitmask* os::Linux::_numa_all_nodes_ptr; 3060 struct bitmask* os::Linux::_numa_nodes_ptr; 3061 3062 bool os::pd_uncommit_memory(char* addr, size_t size) { 3063 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 3064 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 3065 return res != (uintptr_t) MAP_FAILED; 3066 } 3067 3068 static address get_stack_commited_bottom(address bottom, size_t size) { 3069 address nbot = bottom; 3070 address ntop = bottom + size; 3071 3072 size_t page_sz = os::vm_page_size(); 3073 unsigned pages = size / page_sz; 3074 3075 unsigned char vec[1]; 3076 unsigned imin = 1, imax = pages + 1, imid; 3077 int mincore_return_value = 0; 3078 3079 assert(imin <= imax, "Unexpected page size"); 3080 3081 while (imin < imax) { 3082 imid = (imax + imin) / 2; 3083 nbot = ntop - (imid * page_sz); 3084 3085 // Use a trick with mincore to check whether the page is mapped or not. 3086 // mincore sets vec to 1 if page resides in memory and to 0 if page 3087 // is swapped output but if page we are asking for is unmapped 3088 // it returns -1,ENOMEM 3089 mincore_return_value = mincore(nbot, page_sz, vec); 3090 3091 if (mincore_return_value == -1) { 3092 // Page is not mapped go up 3093 // to find first mapped page 3094 if (errno != EAGAIN) { 3095 assert(errno == ENOMEM, "Unexpected mincore errno"); 3096 imax = imid; 3097 } 3098 } else { 3099 // Page is mapped go down 3100 // to find first not mapped page 3101 imin = imid + 1; 3102 } 3103 } 3104 3105 nbot = nbot + page_sz; 3106 3107 // Adjust stack bottom one page up if last checked page is not mapped 3108 if (mincore_return_value == -1) { 3109 nbot = nbot + page_sz; 3110 } 3111 3112 return nbot; 3113 } 3114 3115 3116 // Linux uses a growable mapping for the stack, and if the mapping for 3117 // the stack guard pages is not removed when we detach a thread the 3118 // stack cannot grow beyond the pages where the stack guard was 3119 // mapped. If at some point later in the process the stack expands to 3120 // that point, the Linux kernel cannot expand the stack any further 3121 // because the guard pages are in the way, and a segfault occurs. 3122 // 3123 // However, it's essential not to split the stack region by unmapping 3124 // a region (leaving a hole) that's already part of the stack mapping, 3125 // so if the stack mapping has already grown beyond the guard pages at 3126 // the time we create them, we have to truncate the stack mapping. 3127 // So, we need to know the extent of the stack mapping when 3128 // create_stack_guard_pages() is called. 3129 3130 // We only need this for stacks that are growable: at the time of 3131 // writing thread stacks don't use growable mappings (i.e. those 3132 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this 3133 // only applies to the main thread. 3134 3135 // If the (growable) stack mapping already extends beyond the point 3136 // where we're going to put our guard pages, truncate the mapping at 3137 // that point by munmap()ping it. This ensures that when we later 3138 // munmap() the guard pages we don't leave a hole in the stack 3139 // mapping. This only affects the main/primordial thread 3140 3141 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 3142 if (os::is_primordial_thread()) { 3143 // As we manually grow stack up to bottom inside create_attached_thread(), 3144 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and 3145 // we don't need to do anything special. 3146 // Check it first, before calling heavy function. 3147 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom(); 3148 unsigned char vec[1]; 3149 3150 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) { 3151 // Fallback to slow path on all errors, including EAGAIN 3152 stack_extent = (uintptr_t) get_stack_commited_bottom( 3153 os::Linux::initial_thread_stack_bottom(), 3154 (size_t)addr - stack_extent); 3155 } 3156 3157 if (stack_extent < (uintptr_t)addr) { 3158 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent)); 3159 } 3160 } 3161 3162 return os::commit_memory(addr, size, !ExecMem); 3163 } 3164 3165 // If this is a growable mapping, remove the guard pages entirely by 3166 // munmap()ping them. If not, just call uncommit_memory(). This only 3167 // affects the main/primordial thread, but guard against future OS changes. 3168 // It's safe to always unmap guard pages for primordial thread because we 3169 // always place it right after end of the mapped region. 3170 3171 bool os::remove_stack_guard_pages(char* addr, size_t size) { 3172 uintptr_t stack_extent, stack_base; 3173 3174 if (os::is_primordial_thread()) { 3175 return ::munmap(addr, size) == 0; 3176 } 3177 3178 return os::uncommit_memory(addr, size); 3179 } 3180 3181 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 3182 // at 'requested_addr'. If there are existing memory mappings at the same 3183 // location, however, they will be overwritten. If 'fixed' is false, 3184 // 'requested_addr' is only treated as a hint, the return value may or 3185 // may not start from the requested address. Unlike Linux mmap(), this 3186 // function returns NULL to indicate failure. 3187 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 3188 char * addr; 3189 int flags; 3190 3191 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 3192 if (fixed) { 3193 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address"); 3194 flags |= MAP_FIXED; 3195 } 3196 3197 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 3198 // touch an uncommitted page. Otherwise, the read/write might 3199 // succeed if we have enough swap space to back the physical page. 3200 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 3201 flags, -1, 0); 3202 3203 return addr == MAP_FAILED ? NULL : addr; 3204 } 3205 3206 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address 3207 // (req_addr != NULL) or with a given alignment. 3208 // - bytes shall be a multiple of alignment. 3209 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3210 // - alignment sets the alignment at which memory shall be allocated. 3211 // It must be a multiple of allocation granularity. 3212 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3213 // req_addr or NULL. 3214 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) { 3215 3216 size_t extra_size = bytes; 3217 if (req_addr == NULL && alignment > 0) { 3218 extra_size += alignment; 3219 } 3220 3221 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE, 3222 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 3223 -1, 0); 3224 if (start == MAP_FAILED) { 3225 start = NULL; 3226 } else { 3227 if (req_addr != NULL) { 3228 if (start != req_addr) { 3229 ::munmap(start, extra_size); 3230 start = NULL; 3231 } 3232 } else { 3233 char* const start_aligned = align_up(start, alignment); 3234 char* const end_aligned = start_aligned + bytes; 3235 char* const end = start + extra_size; 3236 if (start_aligned > start) { 3237 ::munmap(start, start_aligned - start); 3238 } 3239 if (end_aligned < end) { 3240 ::munmap(end_aligned, end - end_aligned); 3241 } 3242 start = start_aligned; 3243 } 3244 } 3245 return start; 3246 } 3247 3248 static int anon_munmap(char * addr, size_t size) { 3249 return ::munmap(addr, size) == 0; 3250 } 3251 3252 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 3253 size_t alignment_hint) { 3254 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 3255 } 3256 3257 bool os::pd_release_memory(char* addr, size_t size) { 3258 return anon_munmap(addr, size); 3259 } 3260 3261 static bool linux_mprotect(char* addr, size_t size, int prot) { 3262 // Linux wants the mprotect address argument to be page aligned. 3263 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size()); 3264 3265 // According to SUSv3, mprotect() should only be used with mappings 3266 // established by mmap(), and mmap() always maps whole pages. Unaligned 3267 // 'addr' likely indicates problem in the VM (e.g. trying to change 3268 // protection of malloc'ed or statically allocated memory). Check the 3269 // caller if you hit this assert. 3270 assert(addr == bottom, "sanity check"); 3271 3272 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size()); 3273 return ::mprotect(bottom, size, prot) == 0; 3274 } 3275 3276 // Set protections specified 3277 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 3278 bool is_committed) { 3279 unsigned int p = 0; 3280 switch (prot) { 3281 case MEM_PROT_NONE: p = PROT_NONE; break; 3282 case MEM_PROT_READ: p = PROT_READ; break; 3283 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 3284 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 3285 default: 3286 ShouldNotReachHere(); 3287 } 3288 // is_committed is unused. 3289 return linux_mprotect(addr, bytes, p); 3290 } 3291 3292 bool os::guard_memory(char* addr, size_t size) { 3293 return linux_mprotect(addr, size, PROT_NONE); 3294 } 3295 3296 bool os::unguard_memory(char* addr, size_t size) { 3297 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE); 3298 } 3299 3300 bool os::Linux::transparent_huge_pages_sanity_check(bool warn, 3301 size_t page_size) { 3302 bool result = false; 3303 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE, 3304 MAP_ANONYMOUS|MAP_PRIVATE, 3305 -1, 0); 3306 if (p != MAP_FAILED) { 3307 void *aligned_p = align_up(p, page_size); 3308 3309 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0; 3310 3311 munmap(p, page_size * 2); 3312 } 3313 3314 if (warn && !result) { 3315 warning("TransparentHugePages is not supported by the operating system."); 3316 } 3317 3318 return result; 3319 } 3320 3321 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) { 3322 bool result = false; 3323 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE, 3324 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, 3325 -1, 0); 3326 3327 if (p != MAP_FAILED) { 3328 // We don't know if this really is a huge page or not. 3329 FILE *fp = fopen("/proc/self/maps", "r"); 3330 if (fp) { 3331 while (!feof(fp)) { 3332 char chars[257]; 3333 long x = 0; 3334 if (fgets(chars, sizeof(chars), fp)) { 3335 if (sscanf(chars, "%lx-%*x", &x) == 1 3336 && x == (long)p) { 3337 if (strstr (chars, "hugepage")) { 3338 result = true; 3339 break; 3340 } 3341 } 3342 } 3343 } 3344 fclose(fp); 3345 } 3346 munmap(p, page_size); 3347 } 3348 3349 if (warn && !result) { 3350 warning("HugeTLBFS is not supported by the operating system."); 3351 } 3352 3353 return result; 3354 } 3355 3356 // Set the coredump_filter bits to include largepages in core dump (bit 6) 3357 // 3358 // From the coredump_filter documentation: 3359 // 3360 // - (bit 0) anonymous private memory 3361 // - (bit 1) anonymous shared memory 3362 // - (bit 2) file-backed private memory 3363 // - (bit 3) file-backed shared memory 3364 // - (bit 4) ELF header pages in file-backed private memory areas (it is 3365 // effective only if the bit 2 is cleared) 3366 // - (bit 5) hugetlb private memory 3367 // - (bit 6) hugetlb shared memory 3368 // - (bit 7) dax private memory 3369 // - (bit 8) dax shared memory 3370 // 3371 static void set_coredump_filter(bool largepages, bool dax_shared) { 3372 FILE *f; 3373 long cdm; 3374 bool filter_changed = false; 3375 3376 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { 3377 return; 3378 } 3379 3380 if (fscanf(f, "%lx", &cdm) != 1) { 3381 fclose(f); 3382 return; 3383 } 3384 3385 rewind(f); 3386 3387 if (largepages && (cdm & LARGEPAGES_BIT) == 0) { 3388 cdm |= LARGEPAGES_BIT; 3389 filter_changed = true; 3390 } 3391 if (dax_shared && (cdm & DAX_SHARED_BIT) == 0) { 3392 cdm |= DAX_SHARED_BIT; 3393 filter_changed = true; 3394 } 3395 if (filter_changed) { 3396 fprintf(f, "%#lx", cdm); 3397 } 3398 3399 fclose(f); 3400 } 3401 3402 // Large page support 3403 3404 static size_t _large_page_size = 0; 3405 3406 size_t os::Linux::find_large_page_size() { 3407 size_t large_page_size = 0; 3408 3409 // large_page_size on Linux is used to round up heap size. x86 uses either 3410 // 2M or 4M page, depending on whether PAE (Physical Address Extensions) 3411 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use 3412 // page as large as 256M. 3413 // 3414 // Here we try to figure out page size by parsing /proc/meminfo and looking 3415 // for a line with the following format: 3416 // Hugepagesize: 2048 kB 3417 // 3418 // If we can't determine the value (e.g. /proc is not mounted, or the text 3419 // format has been changed), we'll use the largest page size supported by 3420 // the processor. 3421 3422 #ifndef ZERO 3423 large_page_size = 3424 AARCH64_ONLY(2 * M) 3425 AMD64_ONLY(2 * M) 3426 ARM32_ONLY(2 * M) 3427 IA32_ONLY(4 * M) 3428 IA64_ONLY(256 * M) 3429 PPC_ONLY(4 * M) 3430 S390_ONLY(1 * M) 3431 SPARC_ONLY(4 * M); 3432 #endif // ZERO 3433 3434 FILE *fp = fopen("/proc/meminfo", "r"); 3435 if (fp) { 3436 while (!feof(fp)) { 3437 int x = 0; 3438 char buf[16]; 3439 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { 3440 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { 3441 large_page_size = x * K; 3442 break; 3443 } 3444 } else { 3445 // skip to next line 3446 for (;;) { 3447 int ch = fgetc(fp); 3448 if (ch == EOF || ch == (int)'\n') break; 3449 } 3450 } 3451 } 3452 fclose(fp); 3453 } 3454 3455 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) { 3456 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is " 3457 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size), 3458 proper_unit_for_byte_size(large_page_size)); 3459 } 3460 3461 return large_page_size; 3462 } 3463 3464 size_t os::Linux::setup_large_page_size() { 3465 _large_page_size = Linux::find_large_page_size(); 3466 const size_t default_page_size = (size_t)Linux::page_size(); 3467 if (_large_page_size > default_page_size) { 3468 _page_sizes[0] = _large_page_size; 3469 _page_sizes[1] = default_page_size; 3470 _page_sizes[2] = 0; 3471 } 3472 3473 return _large_page_size; 3474 } 3475 3476 bool os::Linux::setup_large_page_type(size_t page_size) { 3477 if (FLAG_IS_DEFAULT(UseHugeTLBFS) && 3478 FLAG_IS_DEFAULT(UseSHM) && 3479 FLAG_IS_DEFAULT(UseTransparentHugePages)) { 3480 3481 // The type of large pages has not been specified by the user. 3482 3483 // Try UseHugeTLBFS and then UseSHM. 3484 UseHugeTLBFS = UseSHM = true; 3485 3486 // Don't try UseTransparentHugePages since there are known 3487 // performance issues with it turned on. This might change in the future. 3488 UseTransparentHugePages = false; 3489 } 3490 3491 if (UseTransparentHugePages) { 3492 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages); 3493 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) { 3494 UseHugeTLBFS = false; 3495 UseSHM = false; 3496 return true; 3497 } 3498 UseTransparentHugePages = false; 3499 } 3500 3501 if (UseHugeTLBFS) { 3502 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); 3503 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) { 3504 UseSHM = false; 3505 return true; 3506 } 3507 UseHugeTLBFS = false; 3508 } 3509 3510 return UseSHM; 3511 } 3512 3513 void os::large_page_init() { 3514 if (!UseLargePages && 3515 !UseTransparentHugePages && 3516 !UseHugeTLBFS && 3517 !UseSHM) { 3518 // Not using large pages. 3519 return; 3520 } 3521 3522 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) { 3523 // The user explicitly turned off large pages. 3524 // Ignore the rest of the large pages flags. 3525 UseTransparentHugePages = false; 3526 UseHugeTLBFS = false; 3527 UseSHM = false; 3528 return; 3529 } 3530 3531 size_t large_page_size = Linux::setup_large_page_size(); 3532 UseLargePages = Linux::setup_large_page_type(large_page_size); 3533 3534 set_coredump_filter(true /*largepages*/, false /*dax_shared*/); 3535 } 3536 3537 #ifndef SHM_HUGETLB 3538 #define SHM_HUGETLB 04000 3539 #endif 3540 3541 #define shm_warning_format(format, ...) \ 3542 do { \ 3543 if (UseLargePages && \ 3544 (!FLAG_IS_DEFAULT(UseLargePages) || \ 3545 !FLAG_IS_DEFAULT(UseSHM) || \ 3546 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \ 3547 warning(format, __VA_ARGS__); \ 3548 } \ 3549 } while (0) 3550 3551 #define shm_warning(str) shm_warning_format("%s", str) 3552 3553 #define shm_warning_with_errno(str) \ 3554 do { \ 3555 int err = errno; \ 3556 shm_warning_format(str " (error = %d)", err); \ 3557 } while (0) 3558 3559 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) { 3560 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment"); 3561 3562 if (!is_aligned(alignment, SHMLBA)) { 3563 assert(false, "Code below assumes that alignment is at least SHMLBA aligned"); 3564 return NULL; 3565 } 3566 3567 // To ensure that we get 'alignment' aligned memory from shmat, 3568 // we pre-reserve aligned virtual memory and then attach to that. 3569 3570 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL); 3571 if (pre_reserved_addr == NULL) { 3572 // Couldn't pre-reserve aligned memory. 3573 shm_warning("Failed to pre-reserve aligned memory for shmat."); 3574 return NULL; 3575 } 3576 3577 // SHM_REMAP is needed to allow shmat to map over an existing mapping. 3578 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP); 3579 3580 if ((intptr_t)addr == -1) { 3581 int err = errno; 3582 shm_warning_with_errno("Failed to attach shared memory."); 3583 3584 assert(err != EACCES, "Unexpected error"); 3585 assert(err != EIDRM, "Unexpected error"); 3586 assert(err != EINVAL, "Unexpected error"); 3587 3588 // Since we don't know if the kernel unmapped the pre-reserved memory area 3589 // we can't unmap it, since that would potentially unmap memory that was 3590 // mapped from other threads. 3591 return NULL; 3592 } 3593 3594 return addr; 3595 } 3596 3597 static char* shmat_at_address(int shmid, char* req_addr) { 3598 if (!is_aligned(req_addr, SHMLBA)) { 3599 assert(false, "Requested address needs to be SHMLBA aligned"); 3600 return NULL; 3601 } 3602 3603 char* addr = (char*)shmat(shmid, req_addr, 0); 3604 3605 if ((intptr_t)addr == -1) { 3606 shm_warning_with_errno("Failed to attach shared memory."); 3607 return NULL; 3608 } 3609 3610 return addr; 3611 } 3612 3613 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) { 3614 // If a req_addr has been provided, we assume that the caller has already aligned the address. 3615 if (req_addr != NULL) { 3616 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size"); 3617 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment"); 3618 return shmat_at_address(shmid, req_addr); 3619 } 3620 3621 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically 3622 // return large page size aligned memory addresses when req_addr == NULL. 3623 // However, if the alignment is larger than the large page size, we have 3624 // to manually ensure that the memory returned is 'alignment' aligned. 3625 if (alignment > os::large_page_size()) { 3626 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size"); 3627 return shmat_with_alignment(shmid, bytes, alignment); 3628 } else { 3629 return shmat_at_address(shmid, NULL); 3630 } 3631 } 3632 3633 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment, 3634 char* req_addr, bool exec) { 3635 // "exec" is passed in but not used. Creating the shared image for 3636 // the code cache doesn't have an SHM_X executable permission to check. 3637 assert(UseLargePages && UseSHM, "only for SHM large pages"); 3638 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3639 assert(is_aligned(req_addr, alignment), "Unaligned address"); 3640 3641 if (!is_aligned(bytes, os::large_page_size())) { 3642 return NULL; // Fallback to small pages. 3643 } 3644 3645 // Create a large shared memory region to attach to based on size. 3646 // Currently, size is the total size of the heap. 3647 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); 3648 if (shmid == -1) { 3649 // Possible reasons for shmget failure: 3650 // 1. shmmax is too small for Java heap. 3651 // > check shmmax value: cat /proc/sys/kernel/shmmax 3652 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 3653 // 2. not enough large page memory. 3654 // > check available large pages: cat /proc/meminfo 3655 // > increase amount of large pages: 3656 // echo new_value > /proc/sys/vm/nr_hugepages 3657 // Note 1: different Linux may use different name for this property, 3658 // e.g. on Redhat AS-3 it is "hugetlb_pool". 3659 // Note 2: it's possible there's enough physical memory available but 3660 // they are so fragmented after a long run that they can't 3661 // coalesce into large pages. Try to reserve large pages when 3662 // the system is still "fresh". 3663 shm_warning_with_errno("Failed to reserve shared memory."); 3664 return NULL; 3665 } 3666 3667 // Attach to the region. 3668 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr); 3669 3670 // Remove shmid. If shmat() is successful, the actual shared memory segment 3671 // will be deleted when it's detached by shmdt() or when the process 3672 // terminates. If shmat() is not successful this will remove the shared 3673 // segment immediately. 3674 shmctl(shmid, IPC_RMID, NULL); 3675 3676 return addr; 3677 } 3678 3679 static void warn_on_large_pages_failure(char* req_addr, size_t bytes, 3680 int error) { 3681 assert(error == ENOMEM, "Only expect to fail if no memory is available"); 3682 3683 bool warn_on_failure = UseLargePages && 3684 (!FLAG_IS_DEFAULT(UseLargePages) || 3685 !FLAG_IS_DEFAULT(UseHugeTLBFS) || 3686 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 3687 3688 if (warn_on_failure) { 3689 char msg[128]; 3690 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: " 3691 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error); 3692 warning("%s", msg); 3693 } 3694 } 3695 3696 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes, 3697 char* req_addr, 3698 bool exec) { 3699 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3700 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size"); 3701 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3702 3703 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3704 char* addr = (char*)::mmap(req_addr, bytes, prot, 3705 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, 3706 -1, 0); 3707 3708 if (addr == MAP_FAILED) { 3709 warn_on_large_pages_failure(req_addr, bytes, errno); 3710 return NULL; 3711 } 3712 3713 assert(is_aligned(addr, os::large_page_size()), "Must be"); 3714 3715 return addr; 3716 } 3717 3718 // Reserve memory using mmap(MAP_HUGETLB). 3719 // - bytes shall be a multiple of alignment. 3720 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3721 // - alignment sets the alignment at which memory shall be allocated. 3722 // It must be a multiple of allocation granularity. 3723 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3724 // req_addr or NULL. 3725 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes, 3726 size_t alignment, 3727 char* req_addr, 3728 bool exec) { 3729 size_t large_page_size = os::large_page_size(); 3730 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes"); 3731 3732 assert(is_aligned(req_addr, alignment), "Must be"); 3733 assert(is_aligned(bytes, alignment), "Must be"); 3734 3735 // First reserve - but not commit - the address range in small pages. 3736 char* const start = anon_mmap_aligned(bytes, alignment, req_addr); 3737 3738 if (start == NULL) { 3739 return NULL; 3740 } 3741 3742 assert(is_aligned(start, alignment), "Must be"); 3743 3744 char* end = start + bytes; 3745 3746 // Find the regions of the allocated chunk that can be promoted to large pages. 3747 char* lp_start = align_up(start, large_page_size); 3748 char* lp_end = align_down(end, large_page_size); 3749 3750 size_t lp_bytes = lp_end - lp_start; 3751 3752 assert(is_aligned(lp_bytes, large_page_size), "Must be"); 3753 3754 if (lp_bytes == 0) { 3755 // The mapped region doesn't even span the start and the end of a large page. 3756 // Fall back to allocate a non-special area. 3757 ::munmap(start, end - start); 3758 return NULL; 3759 } 3760 3761 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3762 3763 void* result; 3764 3765 // Commit small-paged leading area. 3766 if (start != lp_start) { 3767 result = ::mmap(start, lp_start - start, prot, 3768 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3769 -1, 0); 3770 if (result == MAP_FAILED) { 3771 ::munmap(lp_start, end - lp_start); 3772 return NULL; 3773 } 3774 } 3775 3776 // Commit large-paged area. 3777 result = ::mmap(lp_start, lp_bytes, prot, 3778 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB, 3779 -1, 0); 3780 if (result == MAP_FAILED) { 3781 warn_on_large_pages_failure(lp_start, lp_bytes, errno); 3782 // If the mmap above fails, the large pages region will be unmapped and we 3783 // have regions before and after with small pages. Release these regions. 3784 // 3785 // | mapped | unmapped | mapped | 3786 // ^ ^ ^ ^ 3787 // start lp_start lp_end end 3788 // 3789 ::munmap(start, lp_start - start); 3790 ::munmap(lp_end, end - lp_end); 3791 return NULL; 3792 } 3793 3794 // Commit small-paged trailing area. 3795 if (lp_end != end) { 3796 result = ::mmap(lp_end, end - lp_end, prot, 3797 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3798 -1, 0); 3799 if (result == MAP_FAILED) { 3800 ::munmap(start, lp_end - start); 3801 return NULL; 3802 } 3803 } 3804 3805 return start; 3806 } 3807 3808 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes, 3809 size_t alignment, 3810 char* req_addr, 3811 bool exec) { 3812 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3813 assert(is_aligned(req_addr, alignment), "Must be"); 3814 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be"); 3815 assert(is_power_of_2(os::large_page_size()), "Must be"); 3816 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes"); 3817 3818 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) { 3819 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec); 3820 } else { 3821 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec); 3822 } 3823 } 3824 3825 char* os::reserve_memory_special(size_t bytes, size_t alignment, 3826 char* req_addr, bool exec) { 3827 assert(UseLargePages, "only for large pages"); 3828 3829 char* addr; 3830 if (UseSHM) { 3831 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec); 3832 } else { 3833 assert(UseHugeTLBFS, "must be"); 3834 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec); 3835 } 3836 3837 if (addr != NULL) { 3838 if (UseNUMAInterleaving) { 3839 numa_make_global(addr, bytes); 3840 } 3841 3842 // The memory is committed 3843 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 3844 } 3845 3846 return addr; 3847 } 3848 3849 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) { 3850 // detaching the SHM segment will also delete it, see reserve_memory_special_shm() 3851 return shmdt(base) == 0; 3852 } 3853 3854 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) { 3855 return pd_release_memory(base, bytes); 3856 } 3857 3858 bool os::release_memory_special(char* base, size_t bytes) { 3859 bool res; 3860 if (MemTracker::tracking_level() > NMT_minimal) { 3861 Tracker tkr(Tracker::release); 3862 res = os::Linux::release_memory_special_impl(base, bytes); 3863 if (res) { 3864 tkr.record((address)base, bytes); 3865 } 3866 3867 } else { 3868 res = os::Linux::release_memory_special_impl(base, bytes); 3869 } 3870 return res; 3871 } 3872 3873 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) { 3874 assert(UseLargePages, "only for large pages"); 3875 bool res; 3876 3877 if (UseSHM) { 3878 res = os::Linux::release_memory_special_shm(base, bytes); 3879 } else { 3880 assert(UseHugeTLBFS, "must be"); 3881 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes); 3882 } 3883 return res; 3884 } 3885 3886 size_t os::large_page_size() { 3887 return _large_page_size; 3888 } 3889 3890 // With SysV SHM the entire memory region must be allocated as shared 3891 // memory. 3892 // HugeTLBFS allows application to commit large page memory on demand. 3893 // However, when committing memory with HugeTLBFS fails, the region 3894 // that was supposed to be committed will lose the old reservation 3895 // and allow other threads to steal that memory region. Because of this 3896 // behavior we can't commit HugeTLBFS memory. 3897 bool os::can_commit_large_page_memory() { 3898 return UseTransparentHugePages; 3899 } 3900 3901 bool os::can_execute_large_page_memory() { 3902 return UseTransparentHugePages || UseHugeTLBFS; 3903 } 3904 3905 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) { 3906 assert(file_desc >= 0, "file_desc is not valid"); 3907 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr); 3908 if (result != NULL) { 3909 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) { 3910 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory")); 3911 } 3912 } 3913 return result; 3914 } 3915 3916 // Reserve memory at an arbitrary address, only if that area is 3917 // available (and not reserved for something else). 3918 3919 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 3920 const int max_tries = 10; 3921 char* base[max_tries]; 3922 size_t size[max_tries]; 3923 const size_t gap = 0x000000; 3924 3925 // Assert only that the size is a multiple of the page size, since 3926 // that's all that mmap requires, and since that's all we really know 3927 // about at this low abstraction level. If we need higher alignment, 3928 // we can either pass an alignment to this method or verify alignment 3929 // in one of the methods further up the call chain. See bug 5044738. 3930 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 3931 3932 // Repeatedly allocate blocks until the block is allocated at the 3933 // right spot. 3934 3935 // Linux mmap allows caller to pass an address as hint; give it a try first, 3936 // if kernel honors the hint then we can return immediately. 3937 char * addr = anon_mmap(requested_addr, bytes, false); 3938 if (addr == requested_addr) { 3939 return requested_addr; 3940 } 3941 3942 if (addr != NULL) { 3943 // mmap() is successful but it fails to reserve at the requested address 3944 anon_munmap(addr, bytes); 3945 } 3946 3947 int i; 3948 for (i = 0; i < max_tries; ++i) { 3949 base[i] = reserve_memory(bytes); 3950 3951 if (base[i] != NULL) { 3952 // Is this the block we wanted? 3953 if (base[i] == requested_addr) { 3954 size[i] = bytes; 3955 break; 3956 } 3957 3958 // Does this overlap the block we wanted? Give back the overlapped 3959 // parts and try again. 3960 3961 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i]; 3962 if (top_overlap >= 0 && (size_t)top_overlap < bytes) { 3963 unmap_memory(base[i], top_overlap); 3964 base[i] += top_overlap; 3965 size[i] = bytes - top_overlap; 3966 } else { 3967 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr; 3968 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) { 3969 unmap_memory(requested_addr, bottom_overlap); 3970 size[i] = bytes - bottom_overlap; 3971 } else { 3972 size[i] = bytes; 3973 } 3974 } 3975 } 3976 } 3977 3978 // Give back the unused reserved pieces. 3979 3980 for (int j = 0; j < i; ++j) { 3981 if (base[j] != NULL) { 3982 unmap_memory(base[j], size[j]); 3983 } 3984 } 3985 3986 if (i < max_tries) { 3987 return requested_addr; 3988 } else { 3989 return NULL; 3990 } 3991 } 3992 3993 size_t os::read(int fd, void *buf, unsigned int nBytes) { 3994 return ::read(fd, buf, nBytes); 3995 } 3996 3997 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 3998 return ::pread(fd, buf, nBytes, offset); 3999 } 4000 4001 // Short sleep, direct OS call. 4002 // 4003 // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee 4004 // sched_yield(2) will actually give up the CPU: 4005 // 4006 // * Alone on this pariticular CPU, keeps running. 4007 // * Before the introduction of "skip_buddy" with "compat_yield" disabled 4008 // (pre 2.6.39). 4009 // 4010 // So calling this with 0 is an alternative. 4011 // 4012 void os::naked_short_sleep(jlong ms) { 4013 struct timespec req; 4014 4015 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 4016 req.tv_sec = 0; 4017 if (ms > 0) { 4018 req.tv_nsec = (ms % 1000) * 1000000; 4019 } else { 4020 req.tv_nsec = 1; 4021 } 4022 4023 nanosleep(&req, NULL); 4024 4025 return; 4026 } 4027 4028 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 4029 void os::infinite_sleep() { 4030 while (true) { // sleep forever ... 4031 ::sleep(100); // ... 100 seconds at a time 4032 } 4033 } 4034 4035 // Used to convert frequent JVM_Yield() to nops 4036 bool os::dont_yield() { 4037 return DontYieldALot; 4038 } 4039 4040 void os::naked_yield() { 4041 sched_yield(); 4042 } 4043 4044 //////////////////////////////////////////////////////////////////////////////// 4045 // thread priority support 4046 4047 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER 4048 // only supports dynamic priority, static priority must be zero. For real-time 4049 // applications, Linux supports SCHED_RR which allows static priority (1-99). 4050 // However, for large multi-threaded applications, SCHED_RR is not only slower 4051 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 4052 // of 5 runs - Sep 2005). 4053 // 4054 // The following code actually changes the niceness of kernel-thread/LWP. It 4055 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 4056 // not the entire user process, and user level threads are 1:1 mapped to kernel 4057 // threads. It has always been the case, but could change in the future. For 4058 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 4059 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 4060 4061 int os::java_to_os_priority[CriticalPriority + 1] = { 4062 19, // 0 Entry should never be used 4063 4064 4, // 1 MinPriority 4065 3, // 2 4066 2, // 3 4067 4068 1, // 4 4069 0, // 5 NormPriority 4070 -1, // 6 4071 4072 -2, // 7 4073 -3, // 8 4074 -4, // 9 NearMaxPriority 4075 4076 -5, // 10 MaxPriority 4077 4078 -5 // 11 CriticalPriority 4079 }; 4080 4081 static int prio_init() { 4082 if (ThreadPriorityPolicy == 1) { 4083 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 4084 // if effective uid is not root. Perhaps, a more elegant way of doing 4085 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 4086 if (geteuid() != 0) { 4087 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 4088 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux"); 4089 } 4090 ThreadPriorityPolicy = 0; 4091 } 4092 } 4093 if (UseCriticalJavaThreadPriority) { 4094 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 4095 } 4096 return 0; 4097 } 4098 4099 OSReturn os::set_native_priority(Thread* thread, int newpri) { 4100 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 4101 4102 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 4103 return (ret == 0) ? OS_OK : OS_ERR; 4104 } 4105 4106 OSReturn os::get_native_priority(const Thread* const thread, 4107 int *priority_ptr) { 4108 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 4109 *priority_ptr = java_to_os_priority[NormPriority]; 4110 return OS_OK; 4111 } 4112 4113 errno = 0; 4114 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 4115 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 4116 } 4117 4118 // Hint to the underlying OS that a task switch would not be good. 4119 // Void return because it's a hint and can fail. 4120 void os::hint_no_preempt() {} 4121 4122 //////////////////////////////////////////////////////////////////////////////// 4123 // suspend/resume support 4124 4125 // The low-level signal-based suspend/resume support is a remnant from the 4126 // old VM-suspension that used to be for java-suspension, safepoints etc, 4127 // within hotspot. Currently used by JFR's OSThreadSampler 4128 // 4129 // The remaining code is greatly simplified from the more general suspension 4130 // code that used to be used. 4131 // 4132 // The protocol is quite simple: 4133 // - suspend: 4134 // - sends a signal to the target thread 4135 // - polls the suspend state of the osthread using a yield loop 4136 // - target thread signal handler (SR_handler) sets suspend state 4137 // and blocks in sigsuspend until continued 4138 // - resume: 4139 // - sets target osthread state to continue 4140 // - sends signal to end the sigsuspend loop in the SR_handler 4141 // 4142 // Note that the SR_lock plays no role in this suspend/resume protocol, 4143 // but is checked for NULL in SR_handler as a thread termination indicator. 4144 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs. 4145 // 4146 // Note that resume_clear_context() and suspend_save_context() are needed 4147 // by SR_handler(), so that fetch_frame_from_ucontext() works, 4148 // which in part is used by: 4149 // - Forte Analyzer: AsyncGetCallTrace() 4150 // - StackBanging: get_frame_at_stack_banging_point() 4151 4152 static void resume_clear_context(OSThread *osthread) { 4153 osthread->set_ucontext(NULL); 4154 osthread->set_siginfo(NULL); 4155 } 4156 4157 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, 4158 ucontext_t* context) { 4159 osthread->set_ucontext(context); 4160 osthread->set_siginfo(siginfo); 4161 } 4162 4163 // Handler function invoked when a thread's execution is suspended or 4164 // resumed. We have to be careful that only async-safe functions are 4165 // called here (Note: most pthread functions are not async safe and 4166 // should be avoided.) 4167 // 4168 // Note: sigwait() is a more natural fit than sigsuspend() from an 4169 // interface point of view, but sigwait() prevents the signal hander 4170 // from being run. libpthread would get very confused by not having 4171 // its signal handlers run and prevents sigwait()'s use with the 4172 // mutex granting granting signal. 4173 // 4174 // Currently only ever called on the VMThread and JavaThreads (PC sampling) 4175 // 4176 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 4177 // Save and restore errno to avoid confusing native code with EINTR 4178 // after sigsuspend. 4179 int old_errno = errno; 4180 4181 Thread* thread = Thread::current_or_null_safe(); 4182 assert(thread != NULL, "Missing current thread in SR_handler"); 4183 4184 // On some systems we have seen signal delivery get "stuck" until the signal 4185 // mask is changed as part of thread termination. Check that the current thread 4186 // has not already terminated (via SR_lock()) - else the following assertion 4187 // will fail because the thread is no longer a JavaThread as the ~JavaThread 4188 // destructor has completed. 4189 4190 if (thread->SR_lock() == NULL) { 4191 return; 4192 } 4193 4194 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 4195 4196 OSThread* osthread = thread->osthread(); 4197 4198 os::SuspendResume::State current = osthread->sr.state(); 4199 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 4200 suspend_save_context(osthread, siginfo, context); 4201 4202 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 4203 os::SuspendResume::State state = osthread->sr.suspended(); 4204 if (state == os::SuspendResume::SR_SUSPENDED) { 4205 sigset_t suspend_set; // signals for sigsuspend() 4206 sigemptyset(&suspend_set); 4207 // get current set of blocked signals and unblock resume signal 4208 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 4209 sigdelset(&suspend_set, SR_signum); 4210 4211 sr_semaphore.signal(); 4212 // wait here until we are resumed 4213 while (1) { 4214 sigsuspend(&suspend_set); 4215 4216 os::SuspendResume::State result = osthread->sr.running(); 4217 if (result == os::SuspendResume::SR_RUNNING) { 4218 sr_semaphore.signal(); 4219 break; 4220 } 4221 } 4222 4223 } else if (state == os::SuspendResume::SR_RUNNING) { 4224 // request was cancelled, continue 4225 } else { 4226 ShouldNotReachHere(); 4227 } 4228 4229 resume_clear_context(osthread); 4230 } else if (current == os::SuspendResume::SR_RUNNING) { 4231 // request was cancelled, continue 4232 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 4233 // ignore 4234 } else { 4235 // ignore 4236 } 4237 4238 errno = old_errno; 4239 } 4240 4241 static int SR_initialize() { 4242 struct sigaction act; 4243 char *s; 4244 4245 // Get signal number to use for suspend/resume 4246 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 4247 int sig = ::strtol(s, 0, 10); 4248 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769. 4249 sig < NSIG) { // Must be legal signal and fit into sigflags[]. 4250 SR_signum = sig; 4251 } else { 4252 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.", 4253 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum); 4254 } 4255 } 4256 4257 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 4258 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 4259 4260 sigemptyset(&SR_sigset); 4261 sigaddset(&SR_sigset, SR_signum); 4262 4263 // Set up signal handler for suspend/resume 4264 act.sa_flags = SA_RESTART|SA_SIGINFO; 4265 act.sa_handler = (void (*)(int)) SR_handler; 4266 4267 // SR_signum is blocked by default. 4268 // 4528190 - We also need to block pthread restart signal (32 on all 4269 // supported Linux platforms). Note that LinuxThreads need to block 4270 // this signal for all threads to work properly. So we don't have 4271 // to use hard-coded signal number when setting up the mask. 4272 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 4273 4274 if (sigaction(SR_signum, &act, 0) == -1) { 4275 return -1; 4276 } 4277 4278 // Save signal flag 4279 os::Linux::set_our_sigflags(SR_signum, act.sa_flags); 4280 return 0; 4281 } 4282 4283 static int sr_notify(OSThread* osthread) { 4284 int status = pthread_kill(osthread->pthread_id(), SR_signum); 4285 assert_status(status == 0, status, "pthread_kill"); 4286 return status; 4287 } 4288 4289 // "Randomly" selected value for how long we want to spin 4290 // before bailing out on suspending a thread, also how often 4291 // we send a signal to a thread we want to resume 4292 static const int RANDOMLY_LARGE_INTEGER = 1000000; 4293 static const int RANDOMLY_LARGE_INTEGER2 = 100; 4294 4295 // returns true on success and false on error - really an error is fatal 4296 // but this seems the normal response to library errors 4297 static bool do_suspend(OSThread* osthread) { 4298 assert(osthread->sr.is_running(), "thread should be running"); 4299 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 4300 4301 // mark as suspended and send signal 4302 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 4303 // failed to switch, state wasn't running? 4304 ShouldNotReachHere(); 4305 return false; 4306 } 4307 4308 if (sr_notify(osthread) != 0) { 4309 ShouldNotReachHere(); 4310 } 4311 4312 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 4313 while (true) { 4314 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { 4315 break; 4316 } else { 4317 // timeout 4318 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 4319 if (cancelled == os::SuspendResume::SR_RUNNING) { 4320 return false; 4321 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 4322 // make sure that we consume the signal on the semaphore as well 4323 sr_semaphore.wait(); 4324 break; 4325 } else { 4326 ShouldNotReachHere(); 4327 return false; 4328 } 4329 } 4330 } 4331 4332 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 4333 return true; 4334 } 4335 4336 static void do_resume(OSThread* osthread) { 4337 assert(osthread->sr.is_suspended(), "thread should be suspended"); 4338 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 4339 4340 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 4341 // failed to switch to WAKEUP_REQUEST 4342 ShouldNotReachHere(); 4343 return; 4344 } 4345 4346 while (true) { 4347 if (sr_notify(osthread) == 0) { 4348 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { 4349 if (osthread->sr.is_running()) { 4350 return; 4351 } 4352 } 4353 } else { 4354 ShouldNotReachHere(); 4355 } 4356 } 4357 4358 guarantee(osthread->sr.is_running(), "Must be running!"); 4359 } 4360 4361 /////////////////////////////////////////////////////////////////////////////////// 4362 // signal handling (except suspend/resume) 4363 4364 // This routine may be used by user applications as a "hook" to catch signals. 4365 // The user-defined signal handler must pass unrecognized signals to this 4366 // routine, and if it returns true (non-zero), then the signal handler must 4367 // return immediately. If the flag "abort_if_unrecognized" is true, then this 4368 // routine will never retun false (zero), but instead will execute a VM panic 4369 // routine kill the process. 4370 // 4371 // If this routine returns false, it is OK to call it again. This allows 4372 // the user-defined signal handler to perform checks either before or after 4373 // the VM performs its own checks. Naturally, the user code would be making 4374 // a serious error if it tried to handle an exception (such as a null check 4375 // or breakpoint) that the VM was generating for its own correct operation. 4376 // 4377 // This routine may recognize any of the following kinds of signals: 4378 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 4379 // It should be consulted by handlers for any of those signals. 4380 // 4381 // The caller of this routine must pass in the three arguments supplied 4382 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 4383 // field of the structure passed to sigaction(). This routine assumes that 4384 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 4385 // 4386 // Note that the VM will print warnings if it detects conflicting signal 4387 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 4388 // 4389 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo, 4390 siginfo_t* siginfo, 4391 void* ucontext, 4392 int abort_if_unrecognized); 4393 4394 void signalHandler(int sig, siginfo_t* info, void* uc) { 4395 assert(info != NULL && uc != NULL, "it must be old kernel"); 4396 int orig_errno = errno; // Preserve errno value over signal handler. 4397 JVM_handle_linux_signal(sig, info, uc, true); 4398 errno = orig_errno; 4399 } 4400 4401 4402 // This boolean allows users to forward their own non-matching signals 4403 // to JVM_handle_linux_signal, harmlessly. 4404 bool os::Linux::signal_handlers_are_installed = false; 4405 4406 // For signal-chaining 4407 struct sigaction sigact[NSIG]; 4408 uint64_t sigs = 0; 4409 #if (64 < NSIG-1) 4410 #error "Not all signals can be encoded in sigs. Adapt its type!" 4411 #endif 4412 bool os::Linux::libjsig_is_loaded = false; 4413 typedef struct sigaction *(*get_signal_t)(int); 4414 get_signal_t os::Linux::get_signal_action = NULL; 4415 4416 struct sigaction* os::Linux::get_chained_signal_action(int sig) { 4417 struct sigaction *actp = NULL; 4418 4419 if (libjsig_is_loaded) { 4420 // Retrieve the old signal handler from libjsig 4421 actp = (*get_signal_action)(sig); 4422 } 4423 if (actp == NULL) { 4424 // Retrieve the preinstalled signal handler from jvm 4425 actp = get_preinstalled_handler(sig); 4426 } 4427 4428 return actp; 4429 } 4430 4431 static bool call_chained_handler(struct sigaction *actp, int sig, 4432 siginfo_t *siginfo, void *context) { 4433 // Call the old signal handler 4434 if (actp->sa_handler == SIG_DFL) { 4435 // It's more reasonable to let jvm treat it as an unexpected exception 4436 // instead of taking the default action. 4437 return false; 4438 } else if (actp->sa_handler != SIG_IGN) { 4439 if ((actp->sa_flags & SA_NODEFER) == 0) { 4440 // automaticlly block the signal 4441 sigaddset(&(actp->sa_mask), sig); 4442 } 4443 4444 sa_handler_t hand = NULL; 4445 sa_sigaction_t sa = NULL; 4446 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 4447 // retrieve the chained handler 4448 if (siginfo_flag_set) { 4449 sa = actp->sa_sigaction; 4450 } else { 4451 hand = actp->sa_handler; 4452 } 4453 4454 if ((actp->sa_flags & SA_RESETHAND) != 0) { 4455 actp->sa_handler = SIG_DFL; 4456 } 4457 4458 // try to honor the signal mask 4459 sigset_t oset; 4460 sigemptyset(&oset); 4461 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 4462 4463 // call into the chained handler 4464 if (siginfo_flag_set) { 4465 (*sa)(sig, siginfo, context); 4466 } else { 4467 (*hand)(sig); 4468 } 4469 4470 // restore the signal mask 4471 pthread_sigmask(SIG_SETMASK, &oset, NULL); 4472 } 4473 // Tell jvm's signal handler the signal is taken care of. 4474 return true; 4475 } 4476 4477 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) { 4478 bool chained = false; 4479 // signal-chaining 4480 if (UseSignalChaining) { 4481 struct sigaction *actp = get_chained_signal_action(sig); 4482 if (actp != NULL) { 4483 chained = call_chained_handler(actp, sig, siginfo, context); 4484 } 4485 } 4486 return chained; 4487 } 4488 4489 struct sigaction* os::Linux::get_preinstalled_handler(int sig) { 4490 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) { 4491 return &sigact[sig]; 4492 } 4493 return NULL; 4494 } 4495 4496 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 4497 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4498 sigact[sig] = oldAct; 4499 sigs |= (uint64_t)1 << (sig-1); 4500 } 4501 4502 // for diagnostic 4503 int sigflags[NSIG]; 4504 4505 int os::Linux::get_our_sigflags(int sig) { 4506 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4507 return sigflags[sig]; 4508 } 4509 4510 void os::Linux::set_our_sigflags(int sig, int flags) { 4511 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4512 if (sig > 0 && sig < NSIG) { 4513 sigflags[sig] = flags; 4514 } 4515 } 4516 4517 void os::Linux::set_signal_handler(int sig, bool set_installed) { 4518 // Check for overwrite. 4519 struct sigaction oldAct; 4520 sigaction(sig, (struct sigaction*)NULL, &oldAct); 4521 4522 void* oldhand = oldAct.sa_sigaction 4523 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4524 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4525 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 4526 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 4527 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 4528 if (AllowUserSignalHandlers || !set_installed) { 4529 // Do not overwrite; user takes responsibility to forward to us. 4530 return; 4531 } else if (UseSignalChaining) { 4532 // save the old handler in jvm 4533 save_preinstalled_handler(sig, oldAct); 4534 // libjsig also interposes the sigaction() call below and saves the 4535 // old sigaction on it own. 4536 } else { 4537 fatal("Encountered unexpected pre-existing sigaction handler " 4538 "%#lx for signal %d.", (long)oldhand, sig); 4539 } 4540 } 4541 4542 struct sigaction sigAct; 4543 sigfillset(&(sigAct.sa_mask)); 4544 sigAct.sa_handler = SIG_DFL; 4545 if (!set_installed) { 4546 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4547 } else { 4548 sigAct.sa_sigaction = signalHandler; 4549 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4550 } 4551 // Save flags, which are set by ours 4552 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4553 sigflags[sig] = sigAct.sa_flags; 4554 4555 int ret = sigaction(sig, &sigAct, &oldAct); 4556 assert(ret == 0, "check"); 4557 4558 void* oldhand2 = oldAct.sa_sigaction 4559 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4560 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4561 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 4562 } 4563 4564 // install signal handlers for signals that HotSpot needs to 4565 // handle in order to support Java-level exception handling. 4566 4567 void os::Linux::install_signal_handlers() { 4568 if (!signal_handlers_are_installed) { 4569 signal_handlers_are_installed = true; 4570 4571 // signal-chaining 4572 typedef void (*signal_setting_t)(); 4573 signal_setting_t begin_signal_setting = NULL; 4574 signal_setting_t end_signal_setting = NULL; 4575 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4576 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 4577 if (begin_signal_setting != NULL) { 4578 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4579 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 4580 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 4581 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 4582 libjsig_is_loaded = true; 4583 assert(UseSignalChaining, "should enable signal-chaining"); 4584 } 4585 if (libjsig_is_loaded) { 4586 // Tell libjsig jvm is setting signal handlers 4587 (*begin_signal_setting)(); 4588 } 4589 4590 set_signal_handler(SIGSEGV, true); 4591 set_signal_handler(SIGPIPE, true); 4592 set_signal_handler(SIGBUS, true); 4593 set_signal_handler(SIGILL, true); 4594 set_signal_handler(SIGFPE, true); 4595 #if defined(PPC64) 4596 set_signal_handler(SIGTRAP, true); 4597 #endif 4598 set_signal_handler(SIGXFSZ, true); 4599 4600 if (libjsig_is_loaded) { 4601 // Tell libjsig jvm finishes setting signal handlers 4602 (*end_signal_setting)(); 4603 } 4604 4605 // We don't activate signal checker if libjsig is in place, we trust ourselves 4606 // and if UserSignalHandler is installed all bets are off. 4607 // Log that signal checking is off only if -verbose:jni is specified. 4608 if (CheckJNICalls) { 4609 if (libjsig_is_loaded) { 4610 if (PrintJNIResolving) { 4611 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 4612 } 4613 check_signals = false; 4614 } 4615 if (AllowUserSignalHandlers) { 4616 if (PrintJNIResolving) { 4617 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 4618 } 4619 check_signals = false; 4620 } 4621 } 4622 } 4623 } 4624 4625 // This is the fastest way to get thread cpu time on Linux. 4626 // Returns cpu time (user+sys) for any thread, not only for current. 4627 // POSIX compliant clocks are implemented in the kernels 2.6.16+. 4628 // It might work on 2.6.10+ with a special kernel/glibc patch. 4629 // For reference, please, see IEEE Std 1003.1-2004: 4630 // http://www.unix.org/single_unix_specification 4631 4632 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) { 4633 struct timespec tp; 4634 int rc = os::Linux::clock_gettime(clockid, &tp); 4635 assert(rc == 0, "clock_gettime is expected to return 0 code"); 4636 4637 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec; 4638 } 4639 4640 void os::Linux::initialize_os_info() { 4641 assert(_os_version == 0, "OS info already initialized"); 4642 4643 struct utsname _uname; 4644 4645 uint32_t major; 4646 uint32_t minor; 4647 uint32_t fix; 4648 4649 int rc; 4650 4651 // Kernel version is unknown if 4652 // verification below fails. 4653 _os_version = 0x01000000; 4654 4655 rc = uname(&_uname); 4656 if (rc != -1) { 4657 4658 rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix); 4659 if (rc == 3) { 4660 4661 if (major < 256 && minor < 256 && fix < 256) { 4662 // Kernel version format is as expected, 4663 // set it overriding unknown state. 4664 _os_version = (major << 16) | 4665 (minor << 8 ) | 4666 (fix << 0 ) ; 4667 } 4668 } 4669 } 4670 } 4671 4672 uint32_t os::Linux::os_version() { 4673 assert(_os_version != 0, "not initialized"); 4674 return _os_version & 0x00FFFFFF; 4675 } 4676 4677 bool os::Linux::os_version_is_known() { 4678 assert(_os_version != 0, "not initialized"); 4679 return _os_version & 0x01000000 ? false : true; 4680 } 4681 4682 ///// 4683 // glibc on Linux platform uses non-documented flag 4684 // to indicate, that some special sort of signal 4685 // trampoline is used. 4686 // We will never set this flag, and we should 4687 // ignore this flag in our diagnostic 4688 #ifdef SIGNIFICANT_SIGNAL_MASK 4689 #undef SIGNIFICANT_SIGNAL_MASK 4690 #endif 4691 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 4692 4693 static const char* get_signal_handler_name(address handler, 4694 char* buf, int buflen) { 4695 int offset = 0; 4696 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 4697 if (found) { 4698 // skip directory names 4699 const char *p1, *p2; 4700 p1 = buf; 4701 size_t len = strlen(os::file_separator()); 4702 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 4703 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 4704 } else { 4705 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 4706 } 4707 return buf; 4708 } 4709 4710 static void print_signal_handler(outputStream* st, int sig, 4711 char* buf, size_t buflen) { 4712 struct sigaction sa; 4713 4714 sigaction(sig, NULL, &sa); 4715 4716 // See comment for SIGNIFICANT_SIGNAL_MASK define 4717 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4718 4719 st->print("%s: ", os::exception_name(sig, buf, buflen)); 4720 4721 address handler = (sa.sa_flags & SA_SIGINFO) 4722 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 4723 : CAST_FROM_FN_PTR(address, sa.sa_handler); 4724 4725 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 4726 st->print("SIG_DFL"); 4727 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 4728 st->print("SIG_IGN"); 4729 } else { 4730 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 4731 } 4732 4733 st->print(", sa_mask[0]="); 4734 os::Posix::print_signal_set_short(st, &sa.sa_mask); 4735 4736 address rh = VMError::get_resetted_sighandler(sig); 4737 // May be, handler was resetted by VMError? 4738 if (rh != NULL) { 4739 handler = rh; 4740 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 4741 } 4742 4743 st->print(", sa_flags="); 4744 os::Posix::print_sa_flags(st, sa.sa_flags); 4745 4746 // Check: is it our handler? 4747 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 4748 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 4749 // It is our signal handler 4750 // check for flags, reset system-used one! 4751 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) { 4752 st->print( 4753 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 4754 os::Linux::get_our_sigflags(sig)); 4755 } 4756 } 4757 st->cr(); 4758 } 4759 4760 4761 #define DO_SIGNAL_CHECK(sig) \ 4762 do { \ 4763 if (!sigismember(&check_signal_done, sig)) { \ 4764 os::Linux::check_signal_handler(sig); \ 4765 } \ 4766 } while (0) 4767 4768 // This method is a periodic task to check for misbehaving JNI applications 4769 // under CheckJNI, we can add any periodic checks here 4770 4771 void os::run_periodic_checks() { 4772 if (check_signals == false) return; 4773 4774 // SEGV and BUS if overridden could potentially prevent 4775 // generation of hs*.log in the event of a crash, debugging 4776 // such a case can be very challenging, so we absolutely 4777 // check the following for a good measure: 4778 DO_SIGNAL_CHECK(SIGSEGV); 4779 DO_SIGNAL_CHECK(SIGILL); 4780 DO_SIGNAL_CHECK(SIGFPE); 4781 DO_SIGNAL_CHECK(SIGBUS); 4782 DO_SIGNAL_CHECK(SIGPIPE); 4783 DO_SIGNAL_CHECK(SIGXFSZ); 4784 #if defined(PPC64) 4785 DO_SIGNAL_CHECK(SIGTRAP); 4786 #endif 4787 4788 // ReduceSignalUsage allows the user to override these handlers 4789 // see comments at the very top and jvm_md.h 4790 if (!ReduceSignalUsage) { 4791 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 4792 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 4793 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 4794 DO_SIGNAL_CHECK(BREAK_SIGNAL); 4795 } 4796 4797 DO_SIGNAL_CHECK(SR_signum); 4798 } 4799 4800 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 4801 4802 static os_sigaction_t os_sigaction = NULL; 4803 4804 void os::Linux::check_signal_handler(int sig) { 4805 char buf[O_BUFLEN]; 4806 address jvmHandler = NULL; 4807 4808 4809 struct sigaction act; 4810 if (os_sigaction == NULL) { 4811 // only trust the default sigaction, in case it has been interposed 4812 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 4813 if (os_sigaction == NULL) return; 4814 } 4815 4816 os_sigaction(sig, (struct sigaction*)NULL, &act); 4817 4818 4819 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4820 4821 address thisHandler = (act.sa_flags & SA_SIGINFO) 4822 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 4823 : CAST_FROM_FN_PTR(address, act.sa_handler); 4824 4825 4826 switch (sig) { 4827 case SIGSEGV: 4828 case SIGBUS: 4829 case SIGFPE: 4830 case SIGPIPE: 4831 case SIGILL: 4832 case SIGXFSZ: 4833 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 4834 break; 4835 4836 case SHUTDOWN1_SIGNAL: 4837 case SHUTDOWN2_SIGNAL: 4838 case SHUTDOWN3_SIGNAL: 4839 case BREAK_SIGNAL: 4840 jvmHandler = (address)user_handler(); 4841 break; 4842 4843 default: 4844 if (sig == SR_signum) { 4845 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 4846 } else { 4847 return; 4848 } 4849 break; 4850 } 4851 4852 if (thisHandler != jvmHandler) { 4853 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 4854 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 4855 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 4856 // No need to check this sig any longer 4857 sigaddset(&check_signal_done, sig); 4858 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 4859 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 4860 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 4861 exception_name(sig, buf, O_BUFLEN)); 4862 } 4863 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) { 4864 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 4865 tty->print("expected:"); 4866 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig)); 4867 tty->cr(); 4868 tty->print(" found:"); 4869 os::Posix::print_sa_flags(tty, act.sa_flags); 4870 tty->cr(); 4871 // No need to check this sig any longer 4872 sigaddset(&check_signal_done, sig); 4873 } 4874 4875 // Dump all the signal 4876 if (sigismember(&check_signal_done, sig)) { 4877 print_signal_handlers(tty, buf, O_BUFLEN); 4878 } 4879 } 4880 4881 extern void report_error(char* file_name, int line_no, char* title, 4882 char* format, ...); 4883 4884 // this is called _before_ most of the global arguments have been parsed 4885 void os::init(void) { 4886 char dummy; // used to get a guess on initial stack address 4887 4888 clock_tics_per_sec = sysconf(_SC_CLK_TCK); 4889 4890 init_random(1234567); 4891 4892 Linux::set_page_size(sysconf(_SC_PAGESIZE)); 4893 if (Linux::page_size() == -1) { 4894 fatal("os_linux.cpp: os::init: sysconf failed (%s)", 4895 os::strerror(errno)); 4896 } 4897 init_page_sizes((size_t) Linux::page_size()); 4898 4899 Linux::initialize_system_info(); 4900 4901 Linux::initialize_os_info(); 4902 4903 // _main_thread points to the thread that created/loaded the JVM. 4904 Linux::_main_thread = pthread_self(); 4905 4906 Linux::clock_init(); 4907 initial_time_count = javaTimeNanos(); 4908 4909 // retrieve entry point for pthread_setname_np 4910 Linux::_pthread_setname_np = 4911 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np"); 4912 4913 os::Posix::init(); 4914 } 4915 4916 // To install functions for atexit system call 4917 extern "C" { 4918 static void perfMemory_exit_helper() { 4919 perfMemory_exit(); 4920 } 4921 } 4922 4923 void os::pd_init_container_support() { 4924 OSContainer::init(); 4925 } 4926 4927 // this is called _after_ the global arguments have been parsed 4928 jint os::init_2(void) { 4929 4930 os::Posix::init_2(); 4931 4932 Linux::fast_thread_clock_init(); 4933 4934 // initialize suspend/resume support - must do this before signal_sets_init() 4935 if (SR_initialize() != 0) { 4936 perror("SR_initialize failed"); 4937 return JNI_ERR; 4938 } 4939 4940 Linux::signal_sets_init(); 4941 Linux::install_signal_handlers(); 4942 4943 // Check and sets minimum stack sizes against command line options 4944 if (Posix::set_minimum_stack_sizes() == JNI_ERR) { 4945 return JNI_ERR; 4946 } 4947 Linux::capture_initial_stack(JavaThread::stack_size_at_create()); 4948 4949 #if defined(IA32) 4950 workaround_expand_exec_shield_cs_limit(); 4951 #endif 4952 4953 Linux::libpthread_init(); 4954 Linux::sched_getcpu_init(); 4955 log_info(os)("HotSpot is running with %s, %s", 4956 Linux::glibc_version(), Linux::libpthread_version()); 4957 4958 if (UseNUMA) { 4959 if (!Linux::libnuma_init()) { 4960 UseNUMA = false; 4961 } else { 4962 if ((Linux::numa_max_node() < 1)) { 4963 // There's only one node(they start from 0), disable NUMA. 4964 UseNUMA = false; 4965 } 4966 } 4967 4968 if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) { 4969 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way 4970 // we can make the adaptive lgrp chunk resizing work. If the user specified both 4971 // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn 4972 // and disable adaptive resizing. 4973 if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) { 4974 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, " 4975 "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)"); 4976 UseAdaptiveSizePolicy = false; 4977 UseAdaptiveNUMAChunkSizing = false; 4978 } 4979 } 4980 4981 if (!UseNUMA && ForceNUMA) { 4982 UseNUMA = true; 4983 } 4984 } 4985 4986 if (MaxFDLimit) { 4987 // set the number of file descriptors to max. print out error 4988 // if getrlimit/setrlimit fails but continue regardless. 4989 struct rlimit nbr_files; 4990 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 4991 if (status != 0) { 4992 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno)); 4993 } else { 4994 nbr_files.rlim_cur = nbr_files.rlim_max; 4995 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 4996 if (status != 0) { 4997 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno)); 4998 } 4999 } 5000 } 5001 5002 // Initialize lock used to serialize thread creation (see os::create_thread) 5003 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); 5004 5005 // at-exit methods are called in the reverse order of their registration. 5006 // atexit functions are called on return from main or as a result of a 5007 // call to exit(3C). There can be only 32 of these functions registered 5008 // and atexit() does not set errno. 5009 5010 if (PerfAllowAtExitRegistration) { 5011 // only register atexit functions if PerfAllowAtExitRegistration is set. 5012 // atexit functions can be delayed until process exit time, which 5013 // can be problematic for embedded VM situations. Embedded VMs should 5014 // call DestroyJavaVM() to assure that VM resources are released. 5015 5016 // note: perfMemory_exit_helper atexit function may be removed in 5017 // the future if the appropriate cleanup code can be added to the 5018 // VM_Exit VMOperation's doit method. 5019 if (atexit(perfMemory_exit_helper) != 0) { 5020 warning("os::init_2 atexit(perfMemory_exit_helper) failed"); 5021 } 5022 } 5023 5024 // initialize thread priority policy 5025 prio_init(); 5026 5027 if (!FLAG_IS_DEFAULT(AllocateHeapAt)) { 5028 set_coredump_filter(false /*largepages*/, true /*dax_shared*/); 5029 } 5030 return JNI_OK; 5031 } 5032 5033 // Mark the polling page as unreadable 5034 void os::make_polling_page_unreadable(void) { 5035 if (!guard_memory((char*)_polling_page, Linux::page_size())) { 5036 fatal("Could not disable polling page"); 5037 } 5038 } 5039 5040 // Mark the polling page as readable 5041 void os::make_polling_page_readable(void) { 5042 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) { 5043 fatal("Could not enable polling page"); 5044 } 5045 } 5046 5047 // older glibc versions don't have this macro (which expands to 5048 // an optimized bit-counting function) so we have to roll our own 5049 #ifndef CPU_COUNT 5050 5051 static int _cpu_count(const cpu_set_t* cpus) { 5052 int count = 0; 5053 // only look up to the number of configured processors 5054 for (int i = 0; i < os::processor_count(); i++) { 5055 if (CPU_ISSET(i, cpus)) { 5056 count++; 5057 } 5058 } 5059 return count; 5060 } 5061 5062 #define CPU_COUNT(cpus) _cpu_count(cpus) 5063 5064 #endif // CPU_COUNT 5065 5066 // Get the current number of available processors for this process. 5067 // This value can change at any time during a process's lifetime. 5068 // sched_getaffinity gives an accurate answer as it accounts for cpusets. 5069 // If it appears there may be more than 1024 processors then we do a 5070 // dynamic check - see 6515172 for details. 5071 // If anything goes wrong we fallback to returning the number of online 5072 // processors - which can be greater than the number available to the process. 5073 int os::Linux::active_processor_count() { 5074 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors 5075 cpu_set_t* cpus_p = &cpus; 5076 int cpus_size = sizeof(cpu_set_t); 5077 5078 int configured_cpus = os::processor_count(); // upper bound on available cpus 5079 int cpu_count = 0; 5080 5081 // old build platforms may not support dynamic cpu sets 5082 #ifdef CPU_ALLOC 5083 5084 // To enable easy testing of the dynamic path on different platforms we 5085 // introduce a diagnostic flag: UseCpuAllocPath 5086 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) { 5087 // kernel may use a mask bigger than cpu_set_t 5088 log_trace(os)("active_processor_count: using dynamic path %s" 5089 "- configured processors: %d", 5090 UseCpuAllocPath ? "(forced) " : "", 5091 configured_cpus); 5092 cpus_p = CPU_ALLOC(configured_cpus); 5093 if (cpus_p != NULL) { 5094 cpus_size = CPU_ALLOC_SIZE(configured_cpus); 5095 // zero it just to be safe 5096 CPU_ZERO_S(cpus_size, cpus_p); 5097 } 5098 else { 5099 // failed to allocate so fallback to online cpus 5100 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); 5101 log_trace(os)("active_processor_count: " 5102 "CPU_ALLOC failed (%s) - using " 5103 "online processor count: %d", 5104 os::strerror(errno), online_cpus); 5105 return online_cpus; 5106 } 5107 } 5108 else { 5109 log_trace(os)("active_processor_count: using static path - configured processors: %d", 5110 configured_cpus); 5111 } 5112 #else // CPU_ALLOC 5113 // these stubs won't be executed 5114 #define CPU_COUNT_S(size, cpus) -1 5115 #define CPU_FREE(cpus) 5116 5117 log_trace(os)("active_processor_count: only static path available - configured processors: %d", 5118 configured_cpus); 5119 #endif // CPU_ALLOC 5120 5121 // pid 0 means the current thread - which we have to assume represents the process 5122 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) { 5123 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5124 cpu_count = CPU_COUNT_S(cpus_size, cpus_p); 5125 } 5126 else { 5127 cpu_count = CPU_COUNT(cpus_p); 5128 } 5129 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count); 5130 } 5131 else { 5132 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN); 5133 warning("sched_getaffinity failed (%s)- using online processor count (%d) " 5134 "which may exceed available processors", os::strerror(errno), cpu_count); 5135 } 5136 5137 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5138 CPU_FREE(cpus_p); 5139 } 5140 5141 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check"); 5142 return cpu_count; 5143 } 5144 5145 // Determine the active processor count from one of 5146 // three different sources: 5147 // 5148 // 1. User option -XX:ActiveProcessorCount 5149 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN) 5150 // 3. extracted from cgroup cpu subsystem (shares and quotas) 5151 // 5152 // Option 1, if specified, will always override. 5153 // If the cgroup subsystem is active and configured, we 5154 // will return the min of the cgroup and option 2 results. 5155 // This is required since tools, such as numactl, that 5156 // alter cpu affinity do not update cgroup subsystem 5157 // cpuset configuration files. 5158 int os::active_processor_count() { 5159 // User has overridden the number of active processors 5160 if (ActiveProcessorCount > 0) { 5161 log_trace(os)("active_processor_count: " 5162 "active processor count set by user : %d", 5163 ActiveProcessorCount); 5164 return ActiveProcessorCount; 5165 } 5166 5167 int active_cpus; 5168 if (OSContainer::is_containerized()) { 5169 active_cpus = OSContainer::active_processor_count(); 5170 log_trace(os)("active_processor_count: determined by OSContainer: %d", 5171 active_cpus); 5172 } else { 5173 active_cpus = os::Linux::active_processor_count(); 5174 } 5175 5176 return active_cpus; 5177 } 5178 5179 void os::set_native_thread_name(const char *name) { 5180 if (Linux::_pthread_setname_np) { 5181 char buf [16]; // according to glibc manpage, 16 chars incl. '/0' 5182 snprintf(buf, sizeof(buf), "%s", name); 5183 buf[sizeof(buf) - 1] = '\0'; 5184 const int rc = Linux::_pthread_setname_np(pthread_self(), buf); 5185 // ERANGE should not happen; all other errors should just be ignored. 5186 assert(rc != ERANGE, "pthread_setname_np failed"); 5187 } 5188 } 5189 5190 bool os::distribute_processes(uint length, uint* distribution) { 5191 // Not yet implemented. 5192 return false; 5193 } 5194 5195 bool os::bind_to_processor(uint processor_id) { 5196 // Not yet implemented. 5197 return false; 5198 } 5199 5200 /// 5201 5202 void os::SuspendedThreadTask::internal_do_task() { 5203 if (do_suspend(_thread->osthread())) { 5204 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 5205 do_task(context); 5206 do_resume(_thread->osthread()); 5207 } 5208 } 5209 5210 //////////////////////////////////////////////////////////////////////////////// 5211 // debug support 5212 5213 bool os::find(address addr, outputStream* st) { 5214 Dl_info dlinfo; 5215 memset(&dlinfo, 0, sizeof(dlinfo)); 5216 if (dladdr(addr, &dlinfo) != 0) { 5217 st->print(PTR_FORMAT ": ", p2i(addr)); 5218 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 5219 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname, 5220 p2i(addr) - p2i(dlinfo.dli_saddr)); 5221 } else if (dlinfo.dli_fbase != NULL) { 5222 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase)); 5223 } else { 5224 st->print("<absolute address>"); 5225 } 5226 if (dlinfo.dli_fname != NULL) { 5227 st->print(" in %s", dlinfo.dli_fname); 5228 } 5229 if (dlinfo.dli_fbase != NULL) { 5230 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase)); 5231 } 5232 st->cr(); 5233 5234 if (Verbose) { 5235 // decode some bytes around the PC 5236 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 5237 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 5238 address lowest = (address) dlinfo.dli_sname; 5239 if (!lowest) lowest = (address) dlinfo.dli_fbase; 5240 if (begin < lowest) begin = lowest; 5241 Dl_info dlinfo2; 5242 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 5243 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 5244 end = (address) dlinfo2.dli_saddr; 5245 } 5246 Disassembler::decode(begin, end, st); 5247 } 5248 return true; 5249 } 5250 return false; 5251 } 5252 5253 //////////////////////////////////////////////////////////////////////////////// 5254 // misc 5255 5256 // This does not do anything on Linux. This is basically a hook for being 5257 // able to use structured exception handling (thread-local exception filters) 5258 // on, e.g., Win32. 5259 void 5260 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, 5261 JavaCallArguments* args, Thread* thread) { 5262 f(value, method, args, thread); 5263 } 5264 5265 void os::print_statistics() { 5266 } 5267 5268 bool os::message_box(const char* title, const char* message) { 5269 int i; 5270 fdStream err(defaultStream::error_fd()); 5271 for (i = 0; i < 78; i++) err.print_raw("="); 5272 err.cr(); 5273 err.print_raw_cr(title); 5274 for (i = 0; i < 78; i++) err.print_raw("-"); 5275 err.cr(); 5276 err.print_raw_cr(message); 5277 for (i = 0; i < 78; i++) err.print_raw("="); 5278 err.cr(); 5279 5280 char buf[16]; 5281 // Prevent process from exiting upon "read error" without consuming all CPU 5282 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 5283 5284 return buf[0] == 'y' || buf[0] == 'Y'; 5285 } 5286 5287 int os::stat(const char *path, struct stat *sbuf) { 5288 char pathbuf[MAX_PATH]; 5289 if (strlen(path) > MAX_PATH - 1) { 5290 errno = ENAMETOOLONG; 5291 return -1; 5292 } 5293 os::native_path(strcpy(pathbuf, path)); 5294 return ::stat(pathbuf, sbuf); 5295 } 5296 5297 // Is a (classpath) directory empty? 5298 bool os::dir_is_empty(const char* path) { 5299 DIR *dir = NULL; 5300 struct dirent *ptr; 5301 5302 dir = opendir(path); 5303 if (dir == NULL) return true; 5304 5305 // Scan the directory 5306 bool result = true; 5307 char buf[sizeof(struct dirent) + MAX_PATH]; 5308 while (result && (ptr = ::readdir(dir)) != NULL) { 5309 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 5310 result = false; 5311 } 5312 } 5313 closedir(dir); 5314 return result; 5315 } 5316 5317 // This code originates from JDK's sysOpen and open64_w 5318 // from src/solaris/hpi/src/system_md.c 5319 5320 int os::open(const char *path, int oflag, int mode) { 5321 if (strlen(path) > MAX_PATH - 1) { 5322 errno = ENAMETOOLONG; 5323 return -1; 5324 } 5325 5326 // All file descriptors that are opened in the Java process and not 5327 // specifically destined for a subprocess should have the close-on-exec 5328 // flag set. If we don't set it, then careless 3rd party native code 5329 // might fork and exec without closing all appropriate file descriptors 5330 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in 5331 // turn might: 5332 // 5333 // - cause end-of-file to fail to be detected on some file 5334 // descriptors, resulting in mysterious hangs, or 5335 // 5336 // - might cause an fopen in the subprocess to fail on a system 5337 // suffering from bug 1085341. 5338 // 5339 // (Yes, the default setting of the close-on-exec flag is a Unix 5340 // design flaw) 5341 // 5342 // See: 5343 // 1085341: 32-bit stdio routines should support file descriptors >255 5344 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 5345 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 5346 // 5347 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open(). 5348 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor 5349 // because it saves a system call and removes a small window where the flag 5350 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored 5351 // and we fall back to using FD_CLOEXEC (see below). 5352 #ifdef O_CLOEXEC 5353 oflag |= O_CLOEXEC; 5354 #endif 5355 5356 int fd = ::open64(path, oflag, mode); 5357 if (fd == -1) return -1; 5358 5359 //If the open succeeded, the file might still be a directory 5360 { 5361 struct stat64 buf64; 5362 int ret = ::fstat64(fd, &buf64); 5363 int st_mode = buf64.st_mode; 5364 5365 if (ret != -1) { 5366 if ((st_mode & S_IFMT) == S_IFDIR) { 5367 errno = EISDIR; 5368 ::close(fd); 5369 return -1; 5370 } 5371 } else { 5372 ::close(fd); 5373 return -1; 5374 } 5375 } 5376 5377 #ifdef FD_CLOEXEC 5378 // Validate that the use of the O_CLOEXEC flag on open above worked. 5379 // With recent kernels, we will perform this check exactly once. 5380 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0; 5381 if (!O_CLOEXEC_is_known_to_work) { 5382 int flags = ::fcntl(fd, F_GETFD); 5383 if (flags != -1) { 5384 if ((flags & FD_CLOEXEC) != 0) 5385 O_CLOEXEC_is_known_to_work = 1; 5386 else 5387 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 5388 } 5389 } 5390 #endif 5391 5392 return fd; 5393 } 5394 5395 5396 // create binary file, rewriting existing file if required 5397 int os::create_binary_file(const char* path, bool rewrite_existing) { 5398 int oflags = O_WRONLY | O_CREAT; 5399 if (!rewrite_existing) { 5400 oflags |= O_EXCL; 5401 } 5402 return ::open64(path, oflags, S_IREAD | S_IWRITE); 5403 } 5404 5405 // return current position of file pointer 5406 jlong os::current_file_offset(int fd) { 5407 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR); 5408 } 5409 5410 // move file pointer to the specified offset 5411 jlong os::seek_to_file_offset(int fd, jlong offset) { 5412 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET); 5413 } 5414 5415 // This code originates from JDK's sysAvailable 5416 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 5417 5418 int os::available(int fd, jlong *bytes) { 5419 jlong cur, end; 5420 int mode; 5421 struct stat64 buf64; 5422 5423 if (::fstat64(fd, &buf64) >= 0) { 5424 mode = buf64.st_mode; 5425 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 5426 int n; 5427 if (::ioctl(fd, FIONREAD, &n) >= 0) { 5428 *bytes = n; 5429 return 1; 5430 } 5431 } 5432 } 5433 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) { 5434 return 0; 5435 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) { 5436 return 0; 5437 } else if (::lseek64(fd, cur, SEEK_SET) == -1) { 5438 return 0; 5439 } 5440 *bytes = end - cur; 5441 return 1; 5442 } 5443 5444 // Map a block of memory. 5445 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 5446 char *addr, size_t bytes, bool read_only, 5447 bool allow_exec) { 5448 int prot; 5449 int flags = MAP_PRIVATE; 5450 5451 if (read_only) { 5452 prot = PROT_READ; 5453 } else { 5454 prot = PROT_READ | PROT_WRITE; 5455 } 5456 5457 if (allow_exec) { 5458 prot |= PROT_EXEC; 5459 } 5460 5461 if (addr != NULL) { 5462 flags |= MAP_FIXED; 5463 } 5464 5465 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 5466 fd, file_offset); 5467 if (mapped_address == MAP_FAILED) { 5468 return NULL; 5469 } 5470 return mapped_address; 5471 } 5472 5473 5474 // Remap a block of memory. 5475 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 5476 char *addr, size_t bytes, bool read_only, 5477 bool allow_exec) { 5478 // same as map_memory() on this OS 5479 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 5480 allow_exec); 5481 } 5482 5483 5484 // Unmap a block of memory. 5485 bool os::pd_unmap_memory(char* addr, size_t bytes) { 5486 return munmap(addr, bytes) == 0; 5487 } 5488 5489 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); 5490 5491 static clockid_t thread_cpu_clockid(Thread* thread) { 5492 pthread_t tid = thread->osthread()->pthread_id(); 5493 clockid_t clockid; 5494 5495 // Get thread clockid 5496 int rc = os::Linux::pthread_getcpuclockid(tid, &clockid); 5497 assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code"); 5498 return clockid; 5499 } 5500 5501 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 5502 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 5503 // of a thread. 5504 // 5505 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 5506 // the fast estimate available on the platform. 5507 5508 jlong os::current_thread_cpu_time() { 5509 if (os::Linux::supports_fast_thread_cpu_time()) { 5510 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5511 } else { 5512 // return user + sys since the cost is the same 5513 return slow_thread_cpu_time(Thread::current(), true /* user + sys */); 5514 } 5515 } 5516 5517 jlong os::thread_cpu_time(Thread* thread) { 5518 // consistent with what current_thread_cpu_time() returns 5519 if (os::Linux::supports_fast_thread_cpu_time()) { 5520 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5521 } else { 5522 return slow_thread_cpu_time(thread, true /* user + sys */); 5523 } 5524 } 5525 5526 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 5527 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5528 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5529 } else { 5530 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); 5531 } 5532 } 5533 5534 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5535 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5536 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5537 } else { 5538 return slow_thread_cpu_time(thread, user_sys_cpu_time); 5539 } 5540 } 5541 5542 // -1 on error. 5543 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5544 pid_t tid = thread->osthread()->thread_id(); 5545 char *s; 5546 char stat[2048]; 5547 int statlen; 5548 char proc_name[64]; 5549 int count; 5550 long sys_time, user_time; 5551 char cdummy; 5552 int idummy; 5553 long ldummy; 5554 FILE *fp; 5555 5556 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid); 5557 fp = fopen(proc_name, "r"); 5558 if (fp == NULL) return -1; 5559 statlen = fread(stat, 1, 2047, fp); 5560 stat[statlen] = '\0'; 5561 fclose(fp); 5562 5563 // Skip pid and the command string. Note that we could be dealing with 5564 // weird command names, e.g. user could decide to rename java launcher 5565 // to "java 1.4.2 :)", then the stat file would look like 5566 // 1234 (java 1.4.2 :)) R ... ... 5567 // We don't really need to know the command string, just find the last 5568 // occurrence of ")" and then start parsing from there. See bug 4726580. 5569 s = strrchr(stat, ')'); 5570 if (s == NULL) return -1; 5571 5572 // Skip blank chars 5573 do { s++; } while (s && isspace(*s)); 5574 5575 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", 5576 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy, 5577 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, 5578 &user_time, &sys_time); 5579 if (count != 13) return -1; 5580 if (user_sys_cpu_time) { 5581 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); 5582 } else { 5583 return (jlong)user_time * (1000000000 / clock_tics_per_sec); 5584 } 5585 } 5586 5587 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5588 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5589 info_ptr->may_skip_backward = false; // elapsed time not wall time 5590 info_ptr->may_skip_forward = false; // elapsed time not wall time 5591 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5592 } 5593 5594 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5595 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5596 info_ptr->may_skip_backward = false; // elapsed time not wall time 5597 info_ptr->may_skip_forward = false; // elapsed time not wall time 5598 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5599 } 5600 5601 bool os::is_thread_cpu_time_supported() { 5602 return true; 5603 } 5604 5605 // System loadavg support. Returns -1 if load average cannot be obtained. 5606 // Linux doesn't yet have a (official) notion of processor sets, 5607 // so just return the system wide load average. 5608 int os::loadavg(double loadavg[], int nelem) { 5609 return ::getloadavg(loadavg, nelem); 5610 } 5611 5612 void os::pause() { 5613 char filename[MAX_PATH]; 5614 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 5615 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile); 5616 } else { 5617 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 5618 } 5619 5620 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 5621 if (fd != -1) { 5622 struct stat buf; 5623 ::close(fd); 5624 while (::stat(filename, &buf) == 0) { 5625 (void)::poll(NULL, 0, 100); 5626 } 5627 } else { 5628 jio_fprintf(stderr, 5629 "Could not open pause file '%s', continuing immediately.\n", filename); 5630 } 5631 } 5632 5633 extern char** environ; 5634 5635 // Run the specified command in a separate process. Return its exit value, 5636 // or -1 on failure (e.g. can't fork a new process). 5637 // Unlike system(), this function can be called from signal handler. It 5638 // doesn't block SIGINT et al. 5639 int os::fork_and_exec(char* cmd) { 5640 const char * argv[4] = {"sh", "-c", cmd, NULL}; 5641 5642 pid_t pid = fork(); 5643 5644 if (pid < 0) { 5645 // fork failed 5646 return -1; 5647 5648 } else if (pid == 0) { 5649 // child process 5650 5651 execve("/bin/sh", (char* const*)argv, environ); 5652 5653 // execve failed 5654 _exit(-1); 5655 5656 } else { 5657 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 5658 // care about the actual exit code, for now. 5659 5660 int status; 5661 5662 // Wait for the child process to exit. This returns immediately if 5663 // the child has already exited. */ 5664 while (waitpid(pid, &status, 0) < 0) { 5665 switch (errno) { 5666 case ECHILD: return 0; 5667 case EINTR: break; 5668 default: return -1; 5669 } 5670 } 5671 5672 if (WIFEXITED(status)) { 5673 // The child exited normally; get its exit code. 5674 return WEXITSTATUS(status); 5675 } else if (WIFSIGNALED(status)) { 5676 // The child exited because of a signal 5677 // The best value to return is 0x80 + signal number, 5678 // because that is what all Unix shells do, and because 5679 // it allows callers to distinguish between process exit and 5680 // process death by signal. 5681 return 0x80 + WTERMSIG(status); 5682 } else { 5683 // Unknown exit code; pass it through 5684 return status; 5685 } 5686 } 5687 } 5688 5689 // Get the default path to the core file 5690 // Returns the length of the string 5691 int os::get_core_path(char* buffer, size_t bufferSize) { 5692 /* 5693 * Max length of /proc/sys/kernel/core_pattern is 128 characters. 5694 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt 5695 */ 5696 const int core_pattern_len = 129; 5697 char core_pattern[core_pattern_len] = {0}; 5698 5699 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY); 5700 if (core_pattern_file == -1) { 5701 return -1; 5702 } 5703 5704 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len); 5705 ::close(core_pattern_file); 5706 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') { 5707 return -1; 5708 } 5709 if (core_pattern[ret-1] == '\n') { 5710 core_pattern[ret-1] = '\0'; 5711 } else { 5712 core_pattern[ret] = '\0'; 5713 } 5714 5715 char *pid_pos = strstr(core_pattern, "%p"); 5716 int written; 5717 5718 if (core_pattern[0] == '/') { 5719 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern); 5720 } else { 5721 char cwd[PATH_MAX]; 5722 5723 const char* p = get_current_directory(cwd, PATH_MAX); 5724 if (p == NULL) { 5725 return -1; 5726 } 5727 5728 if (core_pattern[0] == '|') { 5729 written = jio_snprintf(buffer, bufferSize, 5730 "\"%s\" (or dumping to %s/core.%d)", 5731 &core_pattern[1], p, current_process_id()); 5732 } else { 5733 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern); 5734 } 5735 } 5736 5737 if (written < 0) { 5738 return -1; 5739 } 5740 5741 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) { 5742 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY); 5743 5744 if (core_uses_pid_file != -1) { 5745 char core_uses_pid = 0; 5746 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1); 5747 ::close(core_uses_pid_file); 5748 5749 if (core_uses_pid == '1') { 5750 jio_snprintf(buffer + written, bufferSize - written, 5751 ".%d", current_process_id()); 5752 } 5753 } 5754 } 5755 5756 return strlen(buffer); 5757 } 5758 5759 bool os::start_debugging(char *buf, int buflen) { 5760 int len = (int)strlen(buf); 5761 char *p = &buf[len]; 5762 5763 jio_snprintf(p, buflen-len, 5764 "\n\n" 5765 "Do you want to debug the problem?\n\n" 5766 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n" 5767 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n" 5768 "Otherwise, press RETURN to abort...", 5769 os::current_process_id(), os::current_process_id(), 5770 os::current_thread_id(), os::current_thread_id()); 5771 5772 bool yes = os::message_box("Unexpected Error", buf); 5773 5774 if (yes) { 5775 // yes, user asked VM to launch debugger 5776 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d", 5777 os::current_process_id(), os::current_process_id()); 5778 5779 os::fork_and_exec(buf); 5780 yes = false; 5781 } 5782 return yes; 5783 } 5784 5785 5786 // Java/Compiler thread: 5787 // 5788 // Low memory addresses 5789 // P0 +------------------------+ 5790 // | |\ Java thread created by VM does not have glibc 5791 // | glibc guard page | - guard page, attached Java thread usually has 5792 // | |/ 1 glibc guard page. 5793 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 5794 // | |\ 5795 // | HotSpot Guard Pages | - red, yellow and reserved pages 5796 // | |/ 5797 // +------------------------+ JavaThread::stack_reserved_zone_base() 5798 // | |\ 5799 // | Normal Stack | - 5800 // | |/ 5801 // P2 +------------------------+ Thread::stack_base() 5802 // 5803 // Non-Java thread: 5804 // 5805 // Low memory addresses 5806 // P0 +------------------------+ 5807 // | |\ 5808 // | glibc guard page | - usually 1 page 5809 // | |/ 5810 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 5811 // | |\ 5812 // | Normal Stack | - 5813 // | |/ 5814 // P2 +------------------------+ Thread::stack_base() 5815 // 5816 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size 5817 // returned from pthread_attr_getstack(). 5818 // ** Due to NPTL implementation error, linux takes the glibc guard page out 5819 // of the stack size given in pthread_attr. We work around this for 5820 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.) 5821 // 5822 #ifndef ZERO 5823 static void current_stack_region(address * bottom, size_t * size) { 5824 if (os::is_primordial_thread()) { 5825 // primordial thread needs special handling because pthread_getattr_np() 5826 // may return bogus value. 5827 *bottom = os::Linux::initial_thread_stack_bottom(); 5828 *size = os::Linux::initial_thread_stack_size(); 5829 } else { 5830 pthread_attr_t attr; 5831 5832 int rslt = pthread_getattr_np(pthread_self(), &attr); 5833 5834 // JVM needs to know exact stack location, abort if it fails 5835 if (rslt != 0) { 5836 if (rslt == ENOMEM) { 5837 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); 5838 } else { 5839 fatal("pthread_getattr_np failed with error = %d", rslt); 5840 } 5841 } 5842 5843 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { 5844 fatal("Cannot locate current stack attributes!"); 5845 } 5846 5847 // Work around NPTL stack guard error. 5848 size_t guard_size = 0; 5849 rslt = pthread_attr_getguardsize(&attr, &guard_size); 5850 if (rslt != 0) { 5851 fatal("pthread_attr_getguardsize failed with error = %d", rslt); 5852 } 5853 *bottom += guard_size; 5854 *size -= guard_size; 5855 5856 pthread_attr_destroy(&attr); 5857 5858 } 5859 assert(os::current_stack_pointer() >= *bottom && 5860 os::current_stack_pointer() < *bottom + *size, "just checking"); 5861 } 5862 5863 address os::current_stack_base() { 5864 address bottom; 5865 size_t size; 5866 current_stack_region(&bottom, &size); 5867 return (bottom + size); 5868 } 5869 5870 size_t os::current_stack_size() { 5871 // This stack size includes the usable stack and HotSpot guard pages 5872 // (for the threads that have Hotspot guard pages). 5873 address bottom; 5874 size_t size; 5875 current_stack_region(&bottom, &size); 5876 return size; 5877 } 5878 #endif 5879 5880 static inline struct timespec get_mtime(const char* filename) { 5881 struct stat st; 5882 int ret = os::stat(filename, &st); 5883 assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno)); 5884 return st.st_mtim; 5885 } 5886 5887 int os::compare_file_modified_times(const char* file1, const char* file2) { 5888 struct timespec filetime1 = get_mtime(file1); 5889 struct timespec filetime2 = get_mtime(file2); 5890 int diff = filetime1.tv_sec - filetime2.tv_sec; 5891 if (diff == 0) { 5892 return filetime1.tv_nsec - filetime2.tv_nsec; 5893 } 5894 return diff; 5895 } 5896 5897 /////////////// Unit tests /////////////// 5898 5899 #ifndef PRODUCT 5900 5901 #define test_log(...) \ 5902 do { \ 5903 if (VerboseInternalVMTests) { \ 5904 tty->print_cr(__VA_ARGS__); \ 5905 tty->flush(); \ 5906 } \ 5907 } while (false) 5908 5909 class TestReserveMemorySpecial : AllStatic { 5910 public: 5911 static void small_page_write(void* addr, size_t size) { 5912 size_t page_size = os::vm_page_size(); 5913 5914 char* end = (char*)addr + size; 5915 for (char* p = (char*)addr; p < end; p += page_size) { 5916 *p = 1; 5917 } 5918 } 5919 5920 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) { 5921 if (!UseHugeTLBFS) { 5922 return; 5923 } 5924 5925 test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size); 5926 5927 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false); 5928 5929 if (addr != NULL) { 5930 small_page_write(addr, size); 5931 5932 os::Linux::release_memory_special_huge_tlbfs(addr, size); 5933 } 5934 } 5935 5936 static void test_reserve_memory_special_huge_tlbfs_only() { 5937 if (!UseHugeTLBFS) { 5938 return; 5939 } 5940 5941 size_t lp = os::large_page_size(); 5942 5943 for (size_t size = lp; size <= lp * 10; size += lp) { 5944 test_reserve_memory_special_huge_tlbfs_only(size); 5945 } 5946 } 5947 5948 static void test_reserve_memory_special_huge_tlbfs_mixed() { 5949 size_t lp = os::large_page_size(); 5950 size_t ag = os::vm_allocation_granularity(); 5951 5952 // sizes to test 5953 const size_t sizes[] = { 5954 lp, lp + ag, lp + lp / 2, lp * 2, 5955 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2, 5956 lp * 10, lp * 10 + lp / 2 5957 }; 5958 const int num_sizes = sizeof(sizes) / sizeof(size_t); 5959 5960 // For each size/alignment combination, we test three scenarios: 5961 // 1) with req_addr == NULL 5962 // 2) with a non-null req_addr at which we expect to successfully allocate 5963 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we 5964 // expect the allocation to either fail or to ignore req_addr 5965 5966 // Pre-allocate two areas; they shall be as large as the largest allocation 5967 // and aligned to the largest alignment we will be testing. 5968 const size_t mapping_size = sizes[num_sizes - 1] * 2; 5969 char* const mapping1 = (char*) ::mmap(NULL, mapping_size, 5970 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 5971 -1, 0); 5972 assert(mapping1 != MAP_FAILED, "should work"); 5973 5974 char* const mapping2 = (char*) ::mmap(NULL, mapping_size, 5975 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 5976 -1, 0); 5977 assert(mapping2 != MAP_FAILED, "should work"); 5978 5979 // Unmap the first mapping, but leave the second mapping intact: the first 5980 // mapping will serve as a value for a "good" req_addr (case 2). The second 5981 // mapping, still intact, as "bad" req_addr (case 3). 5982 ::munmap(mapping1, mapping_size); 5983 5984 // Case 1 5985 test_log("%s, req_addr NULL:", __FUNCTION__); 5986 test_log("size align result"); 5987 5988 for (int i = 0; i < num_sizes; i++) { 5989 const size_t size = sizes[i]; 5990 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 5991 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false); 5992 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s", 5993 size, alignment, p2i(p), (p != NULL ? "" : "(failed)")); 5994 if (p != NULL) { 5995 assert(is_aligned(p, alignment), "must be"); 5996 small_page_write(p, size); 5997 os::Linux::release_memory_special_huge_tlbfs(p, size); 5998 } 5999 } 6000 } 6001 6002 // Case 2 6003 test_log("%s, req_addr non-NULL:", __FUNCTION__); 6004 test_log("size align req_addr result"); 6005 6006 for (int i = 0; i < num_sizes; i++) { 6007 const size_t size = sizes[i]; 6008 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6009 char* const req_addr = align_up(mapping1, alignment); 6010 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 6011 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 6012 size, alignment, p2i(req_addr), p2i(p), 6013 ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)"))); 6014 if (p != NULL) { 6015 assert(p == req_addr, "must be"); 6016 small_page_write(p, size); 6017 os::Linux::release_memory_special_huge_tlbfs(p, size); 6018 } 6019 } 6020 } 6021 6022 // Case 3 6023 test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__); 6024 test_log("size align req_addr result"); 6025 6026 for (int i = 0; i < num_sizes; i++) { 6027 const size_t size = sizes[i]; 6028 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6029 char* const req_addr = align_up(mapping2, alignment); 6030 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 6031 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 6032 size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)"))); 6033 // as the area around req_addr contains already existing mappings, the API should always 6034 // return NULL (as per contract, it cannot return another address) 6035 assert(p == NULL, "must be"); 6036 } 6037 } 6038 6039 ::munmap(mapping2, mapping_size); 6040 6041 } 6042 6043 static void test_reserve_memory_special_huge_tlbfs() { 6044 if (!UseHugeTLBFS) { 6045 return; 6046 } 6047 6048 test_reserve_memory_special_huge_tlbfs_only(); 6049 test_reserve_memory_special_huge_tlbfs_mixed(); 6050 } 6051 6052 static void test_reserve_memory_special_shm(size_t size, size_t alignment) { 6053 if (!UseSHM) { 6054 return; 6055 } 6056 6057 test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment); 6058 6059 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false); 6060 6061 if (addr != NULL) { 6062 assert(is_aligned(addr, alignment), "Check"); 6063 assert(is_aligned(addr, os::large_page_size()), "Check"); 6064 6065 small_page_write(addr, size); 6066 6067 os::Linux::release_memory_special_shm(addr, size); 6068 } 6069 } 6070 6071 static void test_reserve_memory_special_shm() { 6072 size_t lp = os::large_page_size(); 6073 size_t ag = os::vm_allocation_granularity(); 6074 6075 for (size_t size = ag; size < lp * 3; size += ag) { 6076 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6077 test_reserve_memory_special_shm(size, alignment); 6078 } 6079 } 6080 } 6081 6082 static void test() { 6083 test_reserve_memory_special_huge_tlbfs(); 6084 test_reserve_memory_special_shm(); 6085 } 6086 }; 6087 6088 void TestReserveMemorySpecial_test() { 6089 TestReserveMemorySpecial::test(); 6090 } 6091 6092 #endif