1 /*
2 * Copyright (c) 1999, 2020, 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 "logging/logStream.hpp"
37 #include "memory/allocation.inline.hpp"
38 #include "memory/filemap.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "os_linux.inline.hpp"
41 #include "os_posix.inline.hpp"
42 #include "os_share_linux.hpp"
43 #include "osContainer_linux.hpp"
44 #include "prims/jniFastGetField.hpp"
45 #include "prims/jvm_misc.hpp"
46 #include "runtime/arguments.hpp"
47 #include "runtime/atomic.hpp"
48 #include "runtime/globals.hpp"
49 #include "runtime/interfaceSupport.inline.hpp"
50 #include "runtime/init.hpp"
51 #include "runtime/java.hpp"
52 #include "runtime/javaCalls.hpp"
53 #include "runtime/mutexLocker.hpp"
54 #include "runtime/objectMonitor.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 "runtime/vm_version.hpp"
65 #include "semaphore_posix.hpp"
66 #include "services/attachListener.hpp"
67 #include "services/memTracker.hpp"
68 #include "services/runtimeService.hpp"
69 #include "utilities/align.hpp"
70 #include "utilities/decoder.hpp"
71 #include "utilities/defaultStream.hpp"
72 #include "utilities/events.hpp"
73 #include "utilities/elfFile.hpp"
74 #include "utilities/growableArray.hpp"
75 #include "utilities/macros.hpp"
76 #include "utilities/powerOfTwo.hpp"
77 #include "utilities/vmError.hpp"
78
79 // put OS-includes here
80 # include <sys/types.h>
81 # include <sys/mman.h>
82 # include <sys/stat.h>
83 # include <sys/select.h>
84 # include <pthread.h>
85 # include <signal.h>
86 # include <endian.h>
87 # include <errno.h>
88 # include <dlfcn.h>
89 # include <stdio.h>
90 # include <unistd.h>
91 # include <sys/resource.h>
92 # include <pthread.h>
93 # include <sys/stat.h>
94 # include <sys/time.h>
95 # include <sys/times.h>
96 # include <sys/utsname.h>
97 # include <sys/socket.h>
98 # include <sys/wait.h>
99 # include <pwd.h>
100 # include <poll.h>
101 # include <fcntl.h>
102 # include <string.h>
103 # include <syscall.h>
104 # include <sys/sysinfo.h>
105 # include <gnu/libc-version.h>
106 # include <sys/ipc.h>
107 # include <sys/shm.h>
108 # include <link.h>
109 # include <stdint.h>
110 # include <inttypes.h>
111 # include <sys/ioctl.h>
112 # include <linux/elf-em.h>
113 #ifdef __GLIBC__
114 # include <malloc.h>
115 #endif
116
117 #ifndef _GNU_SOURCE
118 #define _GNU_SOURCE
119 #include <sched.h>
120 #undef _GNU_SOURCE
121 #else
122 #include <sched.h>
123 #endif
124
125 // if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling
126 // getrusage() is prepared to handle the associated failure.
127 #ifndef RUSAGE_THREAD
128 #define RUSAGE_THREAD (1) /* only the calling thread */
129 #endif
130
131 #define MAX_PATH (2 * K)
132
133 #define MAX_SECS 100000000
134
135 // for timer info max values which include all bits
136 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
137
138 enum CoredumpFilterBit {
139 FILE_BACKED_PVT_BIT = 1 << 2,
140 FILE_BACKED_SHARED_BIT = 1 << 3,
141 LARGEPAGES_BIT = 1 << 6,
142 DAX_SHARED_BIT = 1 << 8
143 };
144
145 ////////////////////////////////////////////////////////////////////////////////
146 // global variables
147 julong os::Linux::_physical_memory = 0;
148
149 address os::Linux::_initial_thread_stack_bottom = NULL;
150 uintptr_t os::Linux::_initial_thread_stack_size = 0;
151
152 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL;
153 int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL;
154 pthread_t os::Linux::_main_thread;
155 int os::Linux::_page_size = -1;
156 bool os::Linux::_supports_fast_thread_cpu_time = false;
157 const char * os::Linux::_glibc_version = NULL;
158 const char * os::Linux::_libpthread_version = NULL;
159 size_t os::Linux::_default_large_page_size = 0;
160
161 static jlong initial_time_count=0;
162
163 static int clock_tics_per_sec = 100;
164
165 // If the VM might have been created on the primordial thread, we need to resolve the
166 // primordial thread stack bounds and check if the current thread might be the
167 // primordial thread in places. If we know that the primordial thread is never used,
168 // such as when the VM was created by one of the standard java launchers, we can
169 // avoid this
170 static bool suppress_primordial_thread_resolution = false;
171
172 // For diagnostics to print a message once. see run_periodic_checks
173 static sigset_t check_signal_done;
174 static bool check_signals = true;
175
176 // Signal number used to suspend/resume a thread
177
178 // do not use any signal number less than SIGSEGV, see 4355769
179 static int SR_signum = SIGUSR2;
180 sigset_t SR_sigset;
181
182 // utility functions
183
184 static int SR_initialize();
185
186 julong os::available_memory() {
187 return Linux::available_memory();
188 }
189
190 julong os::Linux::available_memory() {
191 // values in struct sysinfo are "unsigned long"
192 struct sysinfo si;
193 julong avail_mem;
194
195 if (OSContainer::is_containerized()) {
196 jlong mem_limit, mem_usage;
197 if ((mem_limit = OSContainer::memory_limit_in_bytes()) < 1) {
198 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
199 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
200 }
201 if (mem_limit > 0 && (mem_usage = OSContainer::memory_usage_in_bytes()) < 1) {
202 log_debug(os, container)("container memory usage failed: " JLONG_FORMAT ", using host value", mem_usage);
203 }
204 if (mem_limit > 0 && mem_usage > 0 ) {
205 avail_mem = mem_limit > mem_usage ? (julong)mem_limit - (julong)mem_usage : 0;
206 log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem);
207 return avail_mem;
208 }
209 }
210
211 sysinfo(&si);
212 avail_mem = (julong)si.freeram * si.mem_unit;
213 log_trace(os)("available memory: " JULONG_FORMAT, avail_mem);
214 return avail_mem;
215 }
216
217 julong os::physical_memory() {
218 jlong phys_mem = 0;
219 if (OSContainer::is_containerized()) {
220 jlong mem_limit;
221 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) {
222 log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit);
223 return mem_limit;
224 }
225 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
226 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
227 }
228
229 phys_mem = Linux::physical_memory();
230 log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem);
231 return phys_mem;
232 }
233
234 static uint64_t initial_total_ticks = 0;
235 static uint64_t initial_steal_ticks = 0;
236 static bool has_initial_tick_info = false;
237
238 static void next_line(FILE *f) {
239 int c;
240 do {
241 c = fgetc(f);
242 } while (c != '\n' && c != EOF);
243 }
244
245 bool os::Linux::get_tick_information(CPUPerfTicks* pticks, int which_logical_cpu) {
246 FILE* fh;
247 uint64_t userTicks, niceTicks, systemTicks, idleTicks;
248 // since at least kernel 2.6 : iowait: time waiting for I/O to complete
249 // irq: time servicing interrupts; softirq: time servicing softirqs
250 uint64_t iowTicks = 0, irqTicks = 0, sirqTicks= 0;
251 // steal (since kernel 2.6.11): time spent in other OS when running in a virtualized environment
252 uint64_t stealTicks = 0;
253 // guest (since kernel 2.6.24): time spent running a virtual CPU for guest OS under the
254 // control of the Linux kernel
255 uint64_t guestNiceTicks = 0;
256 int logical_cpu = -1;
257 const int required_tickinfo_count = (which_logical_cpu == -1) ? 4 : 5;
258 int n;
259
260 memset(pticks, 0, sizeof(CPUPerfTicks));
261
262 if ((fh = fopen("/proc/stat", "r")) == NULL) {
263 return false;
264 }
265
266 if (which_logical_cpu == -1) {
267 n = fscanf(fh, "cpu " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
268 UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
269 UINT64_FORMAT " " UINT64_FORMAT " ",
270 &userTicks, &niceTicks, &systemTicks, &idleTicks,
271 &iowTicks, &irqTicks, &sirqTicks,
272 &stealTicks, &guestNiceTicks);
273 } else {
274 // Move to next line
275 next_line(fh);
276
277 // find the line for requested cpu faster to just iterate linefeeds?
278 for (int i = 0; i < which_logical_cpu; i++) {
279 next_line(fh);
280 }
281
282 n = fscanf(fh, "cpu%u " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
283 UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
284 UINT64_FORMAT " " UINT64_FORMAT " ",
285 &logical_cpu, &userTicks, &niceTicks,
286 &systemTicks, &idleTicks, &iowTicks, &irqTicks, &sirqTicks,
287 &stealTicks, &guestNiceTicks);
288 }
289
290 fclose(fh);
291 if (n < required_tickinfo_count || logical_cpu != which_logical_cpu) {
292 return false;
293 }
294 pticks->used = userTicks + niceTicks;
295 pticks->usedKernel = systemTicks + irqTicks + sirqTicks;
296 pticks->total = userTicks + niceTicks + systemTicks + idleTicks +
297 iowTicks + irqTicks + sirqTicks + stealTicks + guestNiceTicks;
298
299 if (n > required_tickinfo_count + 3) {
300 pticks->steal = stealTicks;
301 pticks->has_steal_ticks = true;
302 } else {
303 pticks->steal = 0;
304 pticks->has_steal_ticks = false;
305 }
306
307 return true;
308 }
309
310 // Return true if user is running as root.
311
312 bool os::have_special_privileges() {
313 static bool init = false;
314 static bool privileges = false;
315 if (!init) {
316 privileges = (getuid() != geteuid()) || (getgid() != getegid());
317 init = true;
318 }
319 return privileges;
320 }
321
322
323 #ifndef SYS_gettid
324 // i386: 224, ia64: 1105, amd64: 186, sparc 143
325 #ifdef __ia64__
326 #define SYS_gettid 1105
327 #else
328 #ifdef __i386__
329 #define SYS_gettid 224
330 #else
331 #ifdef __amd64__
332 #define SYS_gettid 186
333 #else
334 #ifdef __sparc__
335 #define SYS_gettid 143
336 #else
337 #error define gettid for the arch
338 #endif
339 #endif
340 #endif
341 #endif
342 #endif
343
344
345 // pid_t gettid()
346 //
347 // Returns the kernel thread id of the currently running thread. Kernel
348 // thread id is used to access /proc.
349 pid_t os::Linux::gettid() {
350 int rslt = syscall(SYS_gettid);
351 assert(rslt != -1, "must be."); // old linuxthreads implementation?
352 return (pid_t)rslt;
353 }
354
355 // Most versions of linux have a bug where the number of processors are
356 // determined by looking at the /proc file system. In a chroot environment,
357 // the system call returns 1.
358 static bool unsafe_chroot_detected = false;
359 static const char *unstable_chroot_error = "/proc file system not found.\n"
360 "Java may be unstable running multithreaded in a chroot "
361 "environment on Linux when /proc filesystem is not mounted.";
362
363 void os::Linux::initialize_system_info() {
364 set_processor_count(sysconf(_SC_NPROCESSORS_CONF));
365 if (processor_count() == 1) {
366 pid_t pid = os::Linux::gettid();
367 char fname[32];
368 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid);
369 FILE *fp = fopen(fname, "r");
370 if (fp == NULL) {
371 unsafe_chroot_detected = true;
372 } else {
373 fclose(fp);
374 }
375 }
376 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE);
377 assert(processor_count() > 0, "linux error");
378 }
379
380 void os::init_system_properties_values() {
381 // The next steps are taken in the product version:
382 //
383 // Obtain the JAVA_HOME value from the location of libjvm.so.
384 // This library should be located at:
385 // <JAVA_HOME>/lib/{client|server}/libjvm.so.
386 //
387 // If "/jre/lib/" appears at the right place in the path, then we
388 // assume libjvm.so is installed in a JDK and we use this path.
389 //
390 // Otherwise exit with message: "Could not create the Java virtual machine."
391 //
392 // The following extra steps are taken in the debugging version:
393 //
394 // If "/jre/lib/" does NOT appear at the right place in the path
395 // instead of exit check for $JAVA_HOME environment variable.
396 //
397 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
398 // then we append a fake suffix "hotspot/libjvm.so" to this path so
399 // it looks like libjvm.so is installed there
400 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
401 //
402 // Otherwise exit.
403 //
404 // Important note: if the location of libjvm.so changes this
405 // code needs to be changed accordingly.
406
407 // See ld(1):
408 // The linker uses the following search paths to locate required
409 // shared libraries:
410 // 1: ...
411 // ...
412 // 7: The default directories, normally /lib and /usr/lib.
413 #ifndef OVERRIDE_LIBPATH
414 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390)
415 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib"
416 #else
417 #define DEFAULT_LIBPATH "/lib:/usr/lib"
418 #endif
419 #else
420 #define DEFAULT_LIBPATH OVERRIDE_LIBPATH
421 #endif
422
423 // Base path of extensions installed on the system.
424 #define SYS_EXT_DIR "/usr/java/packages"
425 #define EXTENSIONS_DIR "/lib/ext"
426
427 // Buffer that fits several sprintfs.
428 // Note that the space for the colon and the trailing null are provided
429 // by the nulls included by the sizeof operator.
430 const size_t bufsize =
431 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
432 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
433 char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
434
435 // sysclasspath, java_home, dll_dir
436 {
437 char *pslash;
438 os::jvm_path(buf, bufsize);
439
440 // Found the full path to libjvm.so.
441 // Now cut the path to <java_home>/jre if we can.
442 pslash = strrchr(buf, '/');
443 if (pslash != NULL) {
444 *pslash = '\0'; // Get rid of /libjvm.so.
445 }
446 pslash = strrchr(buf, '/');
447 if (pslash != NULL) {
448 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
449 }
450 Arguments::set_dll_dir(buf);
451
452 if (pslash != NULL) {
453 pslash = strrchr(buf, '/');
454 if (pslash != NULL) {
455 *pslash = '\0'; // Get rid of /lib.
456 }
457 }
458 Arguments::set_java_home(buf);
459 if (!set_boot_path('/', ':')) {
460 vm_exit_during_initialization("Failed setting boot class path.", NULL);
461 }
462 }
463
464 // Where to look for native libraries.
465 //
466 // Note: Due to a legacy implementation, most of the library path
467 // is set in the launcher. This was to accomodate linking restrictions
468 // on legacy Linux implementations (which are no longer supported).
469 // Eventually, all the library path setting will be done here.
470 //
471 // However, to prevent the proliferation of improperly built native
472 // libraries, the new path component /usr/java/packages is added here.
473 // Eventually, all the library path setting will be done here.
474 {
475 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
476 // should always exist (until the legacy problem cited above is
477 // addressed).
478 const char *v = ::getenv("LD_LIBRARY_PATH");
479 const char *v_colon = ":";
480 if (v == NULL) { v = ""; v_colon = ""; }
481 // That's +1 for the colon and +1 for the trailing '\0'.
482 char *ld_library_path = NEW_C_HEAP_ARRAY(char,
483 strlen(v) + 1 +
484 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1,
485 mtInternal);
486 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon);
487 Arguments::set_library_path(ld_library_path);
488 FREE_C_HEAP_ARRAY(char, ld_library_path);
489 }
490
491 // Extensions directories.
492 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
493 Arguments::set_ext_dirs(buf);
494
495 FREE_C_HEAP_ARRAY(char, buf);
496
497 #undef DEFAULT_LIBPATH
498 #undef SYS_EXT_DIR
499 #undef EXTENSIONS_DIR
500 }
501
502 ////////////////////////////////////////////////////////////////////////////////
503 // breakpoint support
504
505 void os::breakpoint() {
506 BREAKPOINT;
507 }
508
509 extern "C" void breakpoint() {
510 // use debugger to set breakpoint here
511 }
512
513 ////////////////////////////////////////////////////////////////////////////////
514 // signal support
515
516 debug_only(static bool signal_sets_initialized = false);
517 static sigset_t unblocked_sigs, vm_sigs;
518
519 void os::Linux::signal_sets_init() {
520 // Should also have an assertion stating we are still single-threaded.
521 assert(!signal_sets_initialized, "Already initialized");
522 // Fill in signals that are necessarily unblocked for all threads in
523 // the VM. Currently, we unblock the following signals:
524 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
525 // by -Xrs (=ReduceSignalUsage));
526 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
527 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
528 // the dispositions or masks wrt these signals.
529 // Programs embedding the VM that want to use the above signals for their
530 // own purposes must, at this time, use the "-Xrs" option to prevent
531 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
532 // (See bug 4345157, and other related bugs).
533 // In reality, though, unblocking these signals is really a nop, since
534 // these signals are not blocked by default.
535 sigemptyset(&unblocked_sigs);
536 sigaddset(&unblocked_sigs, SIGILL);
537 sigaddset(&unblocked_sigs, SIGSEGV);
538 sigaddset(&unblocked_sigs, SIGBUS);
539 sigaddset(&unblocked_sigs, SIGFPE);
540 #if defined(PPC64)
541 sigaddset(&unblocked_sigs, SIGTRAP);
542 #endif
543 sigaddset(&unblocked_sigs, SR_signum);
544
545 if (!ReduceSignalUsage) {
546 if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
547 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
548 }
549 if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
550 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
551 }
552 if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
553 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
554 }
555 }
556 // Fill in signals that are blocked by all but the VM thread.
557 sigemptyset(&vm_sigs);
558 if (!ReduceSignalUsage) {
559 sigaddset(&vm_sigs, BREAK_SIGNAL);
560 }
561 debug_only(signal_sets_initialized = true);
562
563 }
564
565 // These are signals that are unblocked while a thread is running Java.
566 // (For some reason, they get blocked by default.)
567 sigset_t* os::Linux::unblocked_signals() {
568 assert(signal_sets_initialized, "Not initialized");
569 return &unblocked_sigs;
570 }
571
572 // These are the signals that are blocked while a (non-VM) thread is
573 // running Java. Only the VM thread handles these signals.
574 sigset_t* os::Linux::vm_signals() {
575 assert(signal_sets_initialized, "Not initialized");
576 return &vm_sigs;
577 }
578
579 void os::Linux::hotspot_sigmask(Thread* thread) {
580
581 //Save caller's signal mask before setting VM signal mask
582 sigset_t caller_sigmask;
583 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
584
585 OSThread* osthread = thread->osthread();
586 osthread->set_caller_sigmask(caller_sigmask);
587
588 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL);
589
590 if (!ReduceSignalUsage) {
591 if (thread->is_VM_thread()) {
592 // Only the VM thread handles BREAK_SIGNAL ...
593 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
594 } else {
595 // ... all other threads block BREAK_SIGNAL
596 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
597 }
598 }
599 }
600
601 //////////////////////////////////////////////////////////////////////////////
602 // detecting pthread library
603
604 void os::Linux::libpthread_init() {
605 // Save glibc and pthread version strings.
606 #if !defined(_CS_GNU_LIBC_VERSION) || \
607 !defined(_CS_GNU_LIBPTHREAD_VERSION)
608 #error "glibc too old (< 2.3.2)"
609 #endif
610
611 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0);
612 assert(n > 0, "cannot retrieve glibc version");
613 char *str = (char *)malloc(n, mtInternal);
614 confstr(_CS_GNU_LIBC_VERSION, str, n);
615 os::Linux::set_glibc_version(str);
616
617 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
618 assert(n > 0, "cannot retrieve pthread version");
619 str = (char *)malloc(n, mtInternal);
620 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n);
621 os::Linux::set_libpthread_version(str);
622 }
623
624 /////////////////////////////////////////////////////////////////////////////
625 // thread stack expansion
626
627 // os::Linux::manually_expand_stack() takes care of expanding the thread
628 // stack. Note that this is normally not needed: pthread stacks allocate
629 // thread stack using mmap() without MAP_NORESERVE, so the stack is already
630 // committed. Therefore it is not necessary to expand the stack manually.
631 //
632 // Manually expanding the stack was historically needed on LinuxThreads
633 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays
634 // it is kept to deal with very rare corner cases:
635 //
636 // For one, user may run the VM on an own implementation of threads
637 // whose stacks are - like the old LinuxThreads - implemented using
638 // mmap(MAP_GROWSDOWN).
639 //
640 // Also, this coding may be needed if the VM is running on the primordial
641 // thread. Normally we avoid running on the primordial thread; however,
642 // user may still invoke the VM on the primordial thread.
643 //
644 // The following historical comment describes the details about running
645 // on a thread stack allocated with mmap(MAP_GROWSDOWN):
646
647
648 // Force Linux kernel to expand current thread stack. If "bottom" is close
649 // to the stack guard, caller should block all signals.
650 //
651 // MAP_GROWSDOWN:
652 // A special mmap() flag that is used to implement thread stacks. It tells
653 // kernel that the memory region should extend downwards when needed. This
654 // allows early versions of LinuxThreads to only mmap the first few pages
655 // when creating a new thread. Linux kernel will automatically expand thread
656 // stack as needed (on page faults).
657 //
658 // However, because the memory region of a MAP_GROWSDOWN stack can grow on
659 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN
660 // region, it's hard to tell if the fault is due to a legitimate stack
661 // access or because of reading/writing non-exist memory (e.g. buffer
662 // overrun). As a rule, if the fault happens below current stack pointer,
663 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the
664 // application (see Linux kernel fault.c).
665 //
666 // This Linux feature can cause SIGSEGV when VM bangs thread stack for
667 // stack overflow detection.
668 //
669 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do
670 // not use MAP_GROWSDOWN.
671 //
672 // To get around the problem and allow stack banging on Linux, we need to
673 // manually expand thread stack after receiving the SIGSEGV.
674 //
675 // There are two ways to expand thread stack to address "bottom", we used
676 // both of them in JVM before 1.5:
677 // 1. adjust stack pointer first so that it is below "bottom", and then
678 // touch "bottom"
679 // 2. mmap() the page in question
680 //
681 // Now alternate signal stack is gone, it's harder to use 2. For instance,
682 // if current sp is already near the lower end of page 101, and we need to
683 // call mmap() to map page 100, it is possible that part of the mmap() frame
684 // will be placed in page 100. When page 100 is mapped, it is zero-filled.
685 // That will destroy the mmap() frame and cause VM to crash.
686 //
687 // The following code works by adjusting sp first, then accessing the "bottom"
688 // page to force a page fault. Linux kernel will then automatically expand the
689 // stack mapping.
690 //
691 // _expand_stack_to() assumes its frame size is less than page size, which
692 // should always be true if the function is not inlined.
693
694 static void NOINLINE _expand_stack_to(address bottom) {
695 address sp;
696 size_t size;
697 volatile char *p;
698
699 // Adjust bottom to point to the largest address within the same page, it
700 // gives us a one-page buffer if alloca() allocates slightly more memory.
701 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size());
702 bottom += os::Linux::page_size() - 1;
703
704 // sp might be slightly above current stack pointer; if that's the case, we
705 // will alloca() a little more space than necessary, which is OK. Don't use
706 // os::current_stack_pointer(), as its result can be slightly below current
707 // stack pointer, causing us to not alloca enough to reach "bottom".
708 sp = (address)&sp;
709
710 if (sp > bottom) {
711 size = sp - bottom;
712 p = (volatile char *)alloca(size);
713 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?");
714 p[0] = '\0';
715 }
716 }
717
718 void os::Linux::expand_stack_to(address bottom) {
719 _expand_stack_to(bottom);
720 }
721
722 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) {
723 assert(t!=NULL, "just checking");
724 assert(t->osthread()->expanding_stack(), "expand should be set");
725
726 if (t->is_in_usable_stack(addr)) {
727 sigset_t mask_all, old_sigset;
728 sigfillset(&mask_all);
729 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset);
730 _expand_stack_to(addr);
731 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL);
732 return true;
733 }
734 return false;
735 }
736
737 //////////////////////////////////////////////////////////////////////////////
738 // create new thread
739
740 // Thread start routine for all newly created threads
741 static void *thread_native_entry(Thread *thread) {
742
743 thread->record_stack_base_and_size();
744
745 // Try to randomize the cache line index of hot stack frames.
746 // This helps when threads of the same stack traces evict each other's
747 // cache lines. The threads can be either from the same JVM instance, or
748 // from different JVM instances. The benefit is especially true for
749 // processors with hyperthreading technology.
750 static int counter = 0;
751 int pid = os::current_process_id();
752 alloca(((pid ^ counter++) & 7) * 128);
753
754 thread->initialize_thread_current();
755
756 OSThread* osthread = thread->osthread();
757 Monitor* sync = osthread->startThread_lock();
758
759 osthread->set_thread_id(os::current_thread_id());
760
761 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
762 os::current_thread_id(), (uintx) pthread_self());
763
764 if (UseNUMA) {
765 int lgrp_id = os::numa_get_group_id();
766 if (lgrp_id != -1) {
767 thread->set_lgrp_id(lgrp_id);
768 }
769 }
770 // initialize signal mask for this thread
771 os::Linux::hotspot_sigmask(thread);
772
773 // initialize floating point control register
774 os::Linux::init_thread_fpu_state();
775
776 // handshaking with parent thread
777 {
778 MutexLocker ml(sync, Mutex::_no_safepoint_check_flag);
779
780 // notify parent thread
781 osthread->set_state(INITIALIZED);
782 sync->notify_all();
783
784 // wait until os::start_thread()
785 while (osthread->get_state() == INITIALIZED) {
786 sync->wait_without_safepoint_check();
787 }
788 }
789
790 assert(osthread->pthread_id() != 0, "pthread_id was not set as expected");
791
792 // call one more level start routine
793 thread->call_run();
794
795 // Note: at this point the thread object may already have deleted itself.
796 // Prevent dereferencing it from here on out.
797 thread = NULL;
798
799 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
800 os::current_thread_id(), (uintx) pthread_self());
801
802 return 0;
803 }
804
805 // On Linux, glibc places static TLS blocks (for __thread variables) on
806 // the thread stack. This decreases the stack size actually available
807 // to threads.
808 //
809 // For large static TLS sizes, this may cause threads to malfunction due
810 // to insufficient stack space. This is a well-known issue in glibc:
811 // http://sourceware.org/bugzilla/show_bug.cgi?id=11787.
812 //
813 // As a workaround, we call a private but assumed-stable glibc function,
814 // __pthread_get_minstack() to obtain the minstack size and derive the
815 // static TLS size from it. We then increase the user requested stack
816 // size by this TLS size.
817 //
818 // Due to compatibility concerns, this size adjustment is opt-in and
819 // controlled via AdjustStackSizeForTLS.
820 typedef size_t (*GetMinStack)(const pthread_attr_t *attr);
821
822 GetMinStack _get_minstack_func = NULL;
823
824 static void get_minstack_init() {
825 _get_minstack_func =
826 (GetMinStack)dlsym(RTLD_DEFAULT, "__pthread_get_minstack");
827 log_info(os, thread)("Lookup of __pthread_get_minstack %s",
828 _get_minstack_func == NULL ? "failed" : "succeeded");
829 }
830
831 // Returns the size of the static TLS area glibc puts on thread stacks.
832 // The value is cached on first use, which occurs when the first thread
833 // is created during VM initialization.
834 static size_t get_static_tls_area_size(const pthread_attr_t *attr) {
835 size_t tls_size = 0;
836 if (_get_minstack_func != NULL) {
837 // Obtain the pthread minstack size by calling __pthread_get_minstack.
838 size_t minstack_size = _get_minstack_func(attr);
839
840 // Remove non-TLS area size included in minstack size returned
841 // by __pthread_get_minstack() to get the static TLS size.
842 // In glibc before 2.27, minstack size includes guard_size.
843 // In glibc 2.27 and later, guard_size is automatically added
844 // to the stack size by pthread_create and is no longer included
845 // in minstack size. In both cases, the guard_size is taken into
846 // account, so there is no need to adjust the result for that.
847 //
848 // Although __pthread_get_minstack() is a private glibc function,
849 // it is expected to have a stable behavior across future glibc
850 // versions while glibc still allocates the static TLS blocks off
851 // the stack. Following is glibc 2.28 __pthread_get_minstack():
852 //
853 // size_t
854 // __pthread_get_minstack (const pthread_attr_t *attr)
855 // {
856 // return GLRO(dl_pagesize) + __static_tls_size + PTHREAD_STACK_MIN;
857 // }
858 //
859 //
860 // The following 'minstack_size > os::vm_page_size() + PTHREAD_STACK_MIN'
861 // if check is done for precaution.
862 if (minstack_size > (size_t)os::vm_page_size() + PTHREAD_STACK_MIN) {
863 tls_size = minstack_size - os::vm_page_size() - PTHREAD_STACK_MIN;
864 }
865 }
866
867 log_info(os, thread)("Stack size adjustment for TLS is " SIZE_FORMAT,
868 tls_size);
869 return tls_size;
870 }
871
872 bool os::create_thread(Thread* thread, ThreadType thr_type,
873 size_t req_stack_size) {
874 assert(thread->osthread() == NULL, "caller responsible");
875
876 // Allocate the OSThread object
877 OSThread* osthread = new OSThread(NULL, NULL);
878 if (osthread == NULL) {
879 return false;
880 }
881
882 // set the correct thread state
883 osthread->set_thread_type(thr_type);
884
885 // Initial state is ALLOCATED but not INITIALIZED
886 osthread->set_state(ALLOCATED);
887
888 thread->set_osthread(osthread);
889
890 // init thread attributes
891 pthread_attr_t attr;
892 pthread_attr_init(&attr);
893 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
894
895 // Calculate stack size if it's not specified by caller.
896 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
897 // In glibc versions prior to 2.7 the guard size mechanism
898 // is not implemented properly. The posix standard requires adding
899 // the size of the guard pages to the stack size, instead Linux
900 // takes the space out of 'stacksize'. Thus we adapt the requested
901 // stack_size by the size of the guard pages to mimick proper
902 // behaviour. However, be careful not to end up with a size
903 // of zero due to overflow. Don't add the guard page in that case.
904 size_t guard_size = os::Linux::default_guard_size(thr_type);
905 // Configure glibc guard page. Must happen before calling
906 // get_static_tls_area_size(), which uses the guard_size.
907 pthread_attr_setguardsize(&attr, guard_size);
908
909 size_t stack_adjust_size = 0;
910 if (AdjustStackSizeForTLS) {
911 // Adjust the stack_size for on-stack TLS - see get_static_tls_area_size().
912 stack_adjust_size += get_static_tls_area_size(&attr);
913 } else {
914 stack_adjust_size += guard_size;
915 }
916
917 stack_adjust_size = align_up(stack_adjust_size, os::vm_page_size());
918 if (stack_size <= SIZE_MAX - stack_adjust_size) {
919 stack_size += stack_adjust_size;
920 }
921 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned");
922
923 int status = pthread_attr_setstacksize(&attr, stack_size);
924 if (status != 0) {
925 // pthread_attr_setstacksize() function can fail
926 // if the stack size exceeds a system-imposed limit.
927 assert_status(status == EINVAL, status, "pthread_attr_setstacksize");
928 log_warning(os, thread)("The %sthread stack size specified is invalid: " SIZE_FORMAT "k",
929 (thr_type == compiler_thread) ? "compiler " : ((thr_type == java_thread) ? "" : "VM "),
930 stack_size / K);
931 thread->set_osthread(NULL);
932 delete osthread;
933 return false;
934 }
935
936 ThreadState state;
937
938 {
939 pthread_t tid;
940 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
941
942 char buf[64];
943 if (ret == 0) {
944 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
945 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
946 } else {
947 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
948 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
949 // Log some OS information which might explain why creating the thread failed.
950 log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
951 LogStream st(Log(os, thread)::info());
952 os::Posix::print_rlimit_info(&st);
953 os::print_memory_info(&st);
954 os::Linux::print_proc_sys_info(&st);
955 os::Linux::print_container_info(&st);
956 }
957
958 pthread_attr_destroy(&attr);
959
960 if (ret != 0) {
961 // Need to clean up stuff we've allocated so far
962 thread->set_osthread(NULL);
963 delete osthread;
964 return false;
965 }
966
967 // Store pthread info into the OSThread
968 osthread->set_pthread_id(tid);
969
970 // Wait until child thread is either initialized or aborted
971 {
972 Monitor* sync_with_child = osthread->startThread_lock();
973 MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
974 while ((state = osthread->get_state()) == ALLOCATED) {
975 sync_with_child->wait_without_safepoint_check();
976 }
977 }
978 }
979
980 // Aborted due to thread limit being reached
981 if (state == ZOMBIE) {
982 thread->set_osthread(NULL);
983 delete osthread;
984 return false;
985 }
986
987 // The thread is returned suspended (in state INITIALIZED),
988 // and is started higher up in the call chain
989 assert(state == INITIALIZED, "race condition");
990 return true;
991 }
992
993 /////////////////////////////////////////////////////////////////////////////
994 // attach existing thread
995
996 // bootstrap the main thread
997 bool os::create_main_thread(JavaThread* thread) {
998 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread");
999 return create_attached_thread(thread);
1000 }
1001
1002 bool os::create_attached_thread(JavaThread* thread) {
1003 #ifdef ASSERT
1004 thread->verify_not_published();
1005 #endif
1006
1007 // Allocate the OSThread object
1008 OSThread* osthread = new OSThread(NULL, NULL);
1009
1010 if (osthread == NULL) {
1011 return false;
1012 }
1013
1014 // Store pthread info into the OSThread
1015 osthread->set_thread_id(os::Linux::gettid());
1016 osthread->set_pthread_id(::pthread_self());
1017
1018 // initialize floating point control register
1019 os::Linux::init_thread_fpu_state();
1020
1021 // Initial thread state is RUNNABLE
1022 osthread->set_state(RUNNABLE);
1023
1024 thread->set_osthread(osthread);
1025
1026 if (UseNUMA) {
1027 int lgrp_id = os::numa_get_group_id();
1028 if (lgrp_id != -1) {
1029 thread->set_lgrp_id(lgrp_id);
1030 }
1031 }
1032
1033 if (os::is_primordial_thread()) {
1034 // If current thread is primordial thread, its stack is mapped on demand,
1035 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map
1036 // the entire stack region to avoid SEGV in stack banging.
1037 // It is also useful to get around the heap-stack-gap problem on SuSE
1038 // kernel (see 4821821 for details). We first expand stack to the top
1039 // of yellow zone, then enable stack yellow zone (order is significant,
1040 // enabling yellow zone first will crash JVM on SuSE Linux), so there
1041 // is no gap between the last two virtual memory regions.
1042
1043 JavaThread *jt = (JavaThread *)thread;
1044 address addr = jt->stack_reserved_zone_base();
1045 assert(addr != NULL, "initialization problem?");
1046 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled");
1047
1048 osthread->set_expanding_stack();
1049 os::Linux::manually_expand_stack(jt, addr);
1050 osthread->clear_expanding_stack();
1051 }
1052
1053 // initialize signal mask for this thread
1054 // and save the caller's signal mask
1055 os::Linux::hotspot_sigmask(thread);
1056
1057 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
1058 os::current_thread_id(), (uintx) pthread_self());
1059
1060 return true;
1061 }
1062
1063 void os::pd_start_thread(Thread* thread) {
1064 OSThread * osthread = thread->osthread();
1065 assert(osthread->get_state() != INITIALIZED, "just checking");
1066 Monitor* sync_with_child = osthread->startThread_lock();
1067 MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
1068 sync_with_child->notify();
1069 }
1070
1071 // Free Linux resources related to the OSThread
1072 void os::free_thread(OSThread* osthread) {
1073 assert(osthread != NULL, "osthread not set");
1074
1075 // We are told to free resources of the argument thread,
1076 // but we can only really operate on the current thread.
1077 assert(Thread::current()->osthread() == osthread,
1078 "os::free_thread but not current thread");
1079
1080 #ifdef ASSERT
1081 sigset_t current;
1082 sigemptyset(¤t);
1083 pthread_sigmask(SIG_SETMASK, NULL, ¤t);
1084 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!");
1085 #endif
1086
1087 // Restore caller's signal mask
1088 sigset_t sigmask = osthread->caller_sigmask();
1089 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
1090
1091 delete osthread;
1092 }
1093
1094 //////////////////////////////////////////////////////////////////////////////
1095 // primordial thread
1096
1097 // Check if current thread is the primordial thread, similar to Solaris thr_main.
1098 bool os::is_primordial_thread(void) {
1099 if (suppress_primordial_thread_resolution) {
1100 return false;
1101 }
1102 char dummy;
1103 // If called before init complete, thread stack bottom will be null.
1104 // Can be called if fatal error occurs before initialization.
1105 if (os::Linux::initial_thread_stack_bottom() == NULL) return false;
1106 assert(os::Linux::initial_thread_stack_bottom() != NULL &&
1107 os::Linux::initial_thread_stack_size() != 0,
1108 "os::init did not locate primordial thread's stack region");
1109 if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() &&
1110 (address)&dummy < os::Linux::initial_thread_stack_bottom() +
1111 os::Linux::initial_thread_stack_size()) {
1112 return true;
1113 } else {
1114 return false;
1115 }
1116 }
1117
1118 // Find the virtual memory area that contains addr
1119 static bool find_vma(address addr, address* vma_low, address* vma_high) {
1120 FILE *fp = fopen("/proc/self/maps", "r");
1121 if (fp) {
1122 address low, high;
1123 while (!feof(fp)) {
1124 if (fscanf(fp, "%p-%p", &low, &high) == 2) {
1125 if (low <= addr && addr < high) {
1126 if (vma_low) *vma_low = low;
1127 if (vma_high) *vma_high = high;
1128 fclose(fp);
1129 return true;
1130 }
1131 }
1132 for (;;) {
1133 int ch = fgetc(fp);
1134 if (ch == EOF || ch == (int)'\n') break;
1135 }
1136 }
1137 fclose(fp);
1138 }
1139 return false;
1140 }
1141
1142 // Locate primordial thread stack. This special handling of primordial thread stack
1143 // is needed because pthread_getattr_np() on most (all?) Linux distros returns
1144 // bogus value for the primordial process thread. While the launcher has created
1145 // the VM in a new thread since JDK 6, we still have to allow for the use of the
1146 // JNI invocation API from a primordial thread.
1147 void os::Linux::capture_initial_stack(size_t max_size) {
1148
1149 // max_size is either 0 (which means accept OS default for thread stacks) or
1150 // a user-specified value known to be at least the minimum needed. If we
1151 // are actually on the primordial thread we can make it appear that we have a
1152 // smaller max_size stack by inserting the guard pages at that location. But we
1153 // cannot do anything to emulate a larger stack than what has been provided by
1154 // the OS or threading library. In fact if we try to use a stack greater than
1155 // what is set by rlimit then we will crash the hosting process.
1156
1157 // Maximum stack size is the easy part, get it from RLIMIT_STACK.
1158 // If this is "unlimited" then it will be a huge value.
1159 struct rlimit rlim;
1160 getrlimit(RLIMIT_STACK, &rlim);
1161 size_t stack_size = rlim.rlim_cur;
1162
1163 // 6308388: a bug in ld.so will relocate its own .data section to the
1164 // lower end of primordial stack; reduce ulimit -s value a little bit
1165 // so we won't install guard page on ld.so's data section.
1166 // But ensure we don't underflow the stack size - allow 1 page spare
1167 if (stack_size >= (size_t)(3 * page_size())) {
1168 stack_size -= 2 * page_size();
1169 }
1170
1171 // Try to figure out where the stack base (top) is. This is harder.
1172 //
1173 // When an application is started, glibc saves the initial stack pointer in
1174 // a global variable "__libc_stack_end", which is then used by system
1175 // libraries. __libc_stack_end should be pretty close to stack top. The
1176 // variable is available since the very early days. However, because it is
1177 // a private interface, it could disappear in the future.
1178 //
1179 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar
1180 // to __libc_stack_end, it is very close to stack top, but isn't the real
1181 // stack top. Note that /proc may not exist if VM is running as a chroot
1182 // program, so reading /proc/<pid>/stat could fail. Also the contents of
1183 // /proc/<pid>/stat could change in the future (though unlikely).
1184 //
1185 // We try __libc_stack_end first. If that doesn't work, look for
1186 // /proc/<pid>/stat. If neither of them works, we use current stack pointer
1187 // as a hint, which should work well in most cases.
1188
1189 uintptr_t stack_start;
1190
1191 // try __libc_stack_end first
1192 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end");
1193 if (p && *p) {
1194 stack_start = *p;
1195 } else {
1196 // see if we can get the start_stack field from /proc/self/stat
1197 FILE *fp;
1198 int pid;
1199 char state;
1200 int ppid;
1201 int pgrp;
1202 int session;
1203 int nr;
1204 int tpgrp;
1205 unsigned long flags;
1206 unsigned long minflt;
1207 unsigned long cminflt;
1208 unsigned long majflt;
1209 unsigned long cmajflt;
1210 unsigned long utime;
1211 unsigned long stime;
1212 long cutime;
1213 long cstime;
1214 long prio;
1215 long nice;
1216 long junk;
1217 long it_real;
1218 uintptr_t start;
1219 uintptr_t vsize;
1220 intptr_t rss;
1221 uintptr_t rsslim;
1222 uintptr_t scodes;
1223 uintptr_t ecode;
1224 int i;
1225
1226 // Figure what the primordial thread stack base is. Code is inspired
1227 // by email from Hans Boehm. /proc/self/stat begins with current pid,
1228 // followed by command name surrounded by parentheses, state, etc.
1229 char stat[2048];
1230 int statlen;
1231
1232 fp = fopen("/proc/self/stat", "r");
1233 if (fp) {
1234 statlen = fread(stat, 1, 2047, fp);
1235 stat[statlen] = '\0';
1236 fclose(fp);
1237
1238 // Skip pid and the command string. Note that we could be dealing with
1239 // weird command names, e.g. user could decide to rename java launcher
1240 // to "java 1.4.2 :)", then the stat file would look like
1241 // 1234 (java 1.4.2 :)) R ... ...
1242 // We don't really need to know the command string, just find the last
1243 // occurrence of ")" and then start parsing from there. See bug 4726580.
1244 char * s = strrchr(stat, ')');
1245
1246 i = 0;
1247 if (s) {
1248 // Skip blank chars
1249 do { s++; } while (s && isspace(*s));
1250
1251 #define _UFM UINTX_FORMAT
1252 #define _DFM INTX_FORMAT
1253
1254 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2
1255 // 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
1256 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,
1257 &state, // 3 %c
1258 &ppid, // 4 %d
1259 &pgrp, // 5 %d
1260 &session, // 6 %d
1261 &nr, // 7 %d
1262 &tpgrp, // 8 %d
1263 &flags, // 9 %lu
1264 &minflt, // 10 %lu
1265 &cminflt, // 11 %lu
1266 &majflt, // 12 %lu
1267 &cmajflt, // 13 %lu
1268 &utime, // 14 %lu
1269 &stime, // 15 %lu
1270 &cutime, // 16 %ld
1271 &cstime, // 17 %ld
1272 &prio, // 18 %ld
1273 &nice, // 19 %ld
1274 &junk, // 20 %ld
1275 &it_real, // 21 %ld
1276 &start, // 22 UINTX_FORMAT
1277 &vsize, // 23 UINTX_FORMAT
1278 &rss, // 24 INTX_FORMAT
1279 &rsslim, // 25 UINTX_FORMAT
1280 &scodes, // 26 UINTX_FORMAT
1281 &ecode, // 27 UINTX_FORMAT
1282 &stack_start); // 28 UINTX_FORMAT
1283 }
1284
1285 #undef _UFM
1286 #undef _DFM
1287
1288 if (i != 28 - 2) {
1289 assert(false, "Bad conversion from /proc/self/stat");
1290 // product mode - assume we are the primordial thread, good luck in the
1291 // embedded case.
1292 warning("Can't detect primordial thread stack location - bad conversion");
1293 stack_start = (uintptr_t) &rlim;
1294 }
1295 } else {
1296 // For some reason we can't open /proc/self/stat (for example, running on
1297 // FreeBSD with a Linux emulator, or inside chroot), this should work for
1298 // most cases, so don't abort:
1299 warning("Can't detect primordial thread stack location - no /proc/self/stat");
1300 stack_start = (uintptr_t) &rlim;
1301 }
1302 }
1303
1304 // Now we have a pointer (stack_start) very close to the stack top, the
1305 // next thing to do is to figure out the exact location of stack top. We
1306 // can find out the virtual memory area that contains stack_start by
1307 // reading /proc/self/maps, it should be the last vma in /proc/self/maps,
1308 // and its upper limit is the real stack top. (again, this would fail if
1309 // running inside chroot, because /proc may not exist.)
1310
1311 uintptr_t stack_top;
1312 address low, high;
1313 if (find_vma((address)stack_start, &low, &high)) {
1314 // success, "high" is the true stack top. (ignore "low", because initial
1315 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.)
1316 stack_top = (uintptr_t)high;
1317 } else {
1318 // failed, likely because /proc/self/maps does not exist
1319 warning("Can't detect primordial thread stack location - find_vma failed");
1320 // best effort: stack_start is normally within a few pages below the real
1321 // stack top, use it as stack top, and reduce stack size so we won't put
1322 // guard page outside stack.
1323 stack_top = stack_start;
1324 stack_size -= 16 * page_size();
1325 }
1326
1327 // stack_top could be partially down the page so align it
1328 stack_top = align_up(stack_top, page_size());
1329
1330 // Allowed stack value is minimum of max_size and what we derived from rlimit
1331 if (max_size > 0) {
1332 _initial_thread_stack_size = MIN2(max_size, stack_size);
1333 } else {
1334 // Accept the rlimit max, but if stack is unlimited then it will be huge, so
1335 // clamp it at 8MB as we do on Solaris
1336 _initial_thread_stack_size = MIN2(stack_size, 8*M);
1337 }
1338 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size());
1339 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size;
1340
1341 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!");
1342
1343 if (log_is_enabled(Info, os, thread)) {
1344 // See if we seem to be on primordial process thread
1345 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) &&
1346 uintptr_t(&rlim) < stack_top;
1347
1348 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: "
1349 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT,
1350 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K,
1351 stack_top, intptr_t(_initial_thread_stack_bottom));
1352 }
1353 }
1354
1355 ////////////////////////////////////////////////////////////////////////////////
1356 // time support
1357
1358 #ifndef SUPPORTS_CLOCK_MONOTONIC
1359 #error "Build platform doesn't support clock_gettime and related functionality"
1360 #endif
1361
1362 // Time since start-up in seconds to a fine granularity.
1363 // Used by VMSelfDestructTimer and the MemProfiler.
1364 double os::elapsedTime() {
1365
1366 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
1367 }
1368
1369 jlong os::elapsed_counter() {
1370 return javaTimeNanos() - initial_time_count;
1371 }
1372
1373 jlong os::elapsed_frequency() {
1374 return NANOSECS_PER_SEC; // nanosecond resolution
1375 }
1376
1377 bool os::supports_vtime() { return true; }
1378
1379 double os::elapsedVTime() {
1380 struct rusage usage;
1381 int retval = getrusage(RUSAGE_THREAD, &usage);
1382 if (retval == 0) {
1383 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);
1384 } else {
1385 // better than nothing, but not much
1386 return elapsedTime();
1387 }
1388 }
1389
1390 jlong os::javaTimeMillis() {
1391 if (os::Posix::supports_clock_gettime()) {
1392 struct timespec ts;
1393 int status = os::Posix::clock_gettime(CLOCK_REALTIME, &ts);
1394 assert_status(status == 0, status, "gettime error");
1395 return jlong(ts.tv_sec) * MILLIUNITS +
1396 jlong(ts.tv_nsec) / NANOUNITS_PER_MILLIUNIT;
1397 } else {
1398 timeval time;
1399 int status = gettimeofday(&time, NULL);
1400 assert(status != -1, "linux error");
1401 return jlong(time.tv_sec) * MILLIUNITS +
1402 jlong(time.tv_usec) / (MICROUNITS / MILLIUNITS);
1403 }
1404 }
1405
1406 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
1407 if (os::Posix::supports_clock_gettime()) {
1408 struct timespec ts;
1409 int status = os::Posix::clock_gettime(CLOCK_REALTIME, &ts);
1410 assert_status(status == 0, status, "gettime error");
1411 seconds = jlong(ts.tv_sec);
1412 nanos = jlong(ts.tv_nsec);
1413 } else {
1414 timeval time;
1415 int status = gettimeofday(&time, NULL);
1416 assert(status != -1, "linux error");
1417 seconds = jlong(time.tv_sec);
1418 nanos = jlong(time.tv_usec) * (NANOUNITS / MICROUNITS);
1419 }
1420 }
1421
1422 void os::Linux::fast_thread_clock_init() {
1423 if (!UseLinuxPosixThreadCPUClocks) {
1424 return;
1425 }
1426 clockid_t clockid;
1427 struct timespec tp;
1428 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) =
1429 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid");
1430
1431 // Switch to using fast clocks for thread cpu time if
1432 // the clock_getres() returns 0 error code.
1433 // Note, that some kernels may support the current thread
1434 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks
1435 // returned by the pthread_getcpuclockid().
1436 // If the fast Posix clocks are supported then the clock_getres()
1437 // must return at least tp.tv_sec == 0 which means a resolution
1438 // better than 1 sec. This is extra check for reliability.
1439
1440 if (pthread_getcpuclockid_func &&
1441 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 &&
1442 os::Posix::clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) {
1443 _supports_fast_thread_cpu_time = true;
1444 _pthread_getcpuclockid = pthread_getcpuclockid_func;
1445 }
1446 }
1447
1448 jlong os::javaTimeNanos() {
1449 if (os::supports_monotonic_clock()) {
1450 struct timespec tp;
1451 int status = os::Posix::clock_gettime(CLOCK_MONOTONIC, &tp);
1452 assert(status == 0, "gettime error");
1453 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1454 return result;
1455 } else {
1456 timeval time;
1457 int status = gettimeofday(&time, NULL);
1458 assert(status != -1, "linux error");
1459 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1460 return 1000 * usecs;
1461 }
1462 }
1463
1464 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1465 if (os::supports_monotonic_clock()) {
1466 info_ptr->max_value = ALL_64_BITS;
1467
1468 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1469 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1470 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1471 } else {
1472 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1473 info_ptr->max_value = ALL_64_BITS;
1474
1475 // gettimeofday is a real time clock so it skips
1476 info_ptr->may_skip_backward = true;
1477 info_ptr->may_skip_forward = true;
1478 }
1479
1480 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1481 }
1482
1483 // Return the real, user, and system times in seconds from an
1484 // arbitrary fixed point in the past.
1485 bool os::getTimesSecs(double* process_real_time,
1486 double* process_user_time,
1487 double* process_system_time) {
1488 struct tms ticks;
1489 clock_t real_ticks = times(&ticks);
1490
1491 if (real_ticks == (clock_t) (-1)) {
1492 return false;
1493 } else {
1494 double ticks_per_second = (double) clock_tics_per_sec;
1495 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1496 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1497 *process_real_time = ((double) real_ticks) / ticks_per_second;
1498
1499 return true;
1500 }
1501 }
1502
1503
1504 char * os::local_time_string(char *buf, size_t buflen) {
1505 struct tm t;
1506 time_t long_time;
1507 time(&long_time);
1508 localtime_r(&long_time, &t);
1509 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1510 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1511 t.tm_hour, t.tm_min, t.tm_sec);
1512 return buf;
1513 }
1514
1515 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1516 return localtime_r(clock, res);
1517 }
1518
1519 ////////////////////////////////////////////////////////////////////////////////
1520 // runtime exit support
1521
1522 // Note: os::shutdown() might be called very early during initialization, or
1523 // called from signal handler. Before adding something to os::shutdown(), make
1524 // sure it is async-safe and can handle partially initialized VM.
1525 void os::shutdown() {
1526
1527 // allow PerfMemory to attempt cleanup of any persistent resources
1528 perfMemory_exit();
1529
1530 // needs to remove object in file system
1531 AttachListener::abort();
1532
1533 // flush buffered output, finish log files
1534 ostream_abort();
1535
1536 // Check for abort hook
1537 abort_hook_t abort_hook = Arguments::abort_hook();
1538 if (abort_hook != NULL) {
1539 abort_hook();
1540 }
1541
1542 }
1543
1544 // Note: os::abort() might be called very early during initialization, or
1545 // called from signal handler. Before adding something to os::abort(), make
1546 // sure it is async-safe and can handle partially initialized VM.
1547 void os::abort(bool dump_core, void* siginfo, const void* context) {
1548 os::shutdown();
1549 if (dump_core) {
1550 if (DumpPrivateMappingsInCore) {
1551 ClassLoader::close_jrt_image();
1552 }
1553 ::abort(); // dump core
1554 }
1555
1556 ::exit(1);
1557 }
1558
1559 // Die immediately, no exit hook, no abort hook, no cleanup.
1560 // Dump a core file, if possible, for debugging.
1561 void os::die() {
1562 if (TestUnresponsiveErrorHandler && !CreateCoredumpOnCrash) {
1563 // For TimeoutInErrorHandlingTest.java, we just kill the VM
1564 // and don't take the time to generate a core file.
1565 os::signal_raise(SIGKILL);
1566 } else {
1567 ::abort();
1568 }
1569 }
1570
1571 // thread_id is kernel thread id (similar to Solaris LWP id)
1572 intx os::current_thread_id() { return os::Linux::gettid(); }
1573 int os::current_process_id() {
1574 return ::getpid();
1575 }
1576
1577 // DLL functions
1578
1579 const char* os::dll_file_extension() { return ".so"; }
1580
1581 // This must be hard coded because it's the system's temporary
1582 // directory not the java application's temp directory, ala java.io.tmpdir.
1583 const char* os::get_temp_directory() { return "/tmp"; }
1584
1585 static bool file_exists(const char* filename) {
1586 struct stat statbuf;
1587 if (filename == NULL || strlen(filename) == 0) {
1588 return false;
1589 }
1590 return os::stat(filename, &statbuf) == 0;
1591 }
1592
1593 // check if addr is inside libjvm.so
1594 bool os::address_is_in_vm(address addr) {
1595 static address libjvm_base_addr;
1596 Dl_info dlinfo;
1597
1598 if (libjvm_base_addr == NULL) {
1599 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1600 libjvm_base_addr = (address)dlinfo.dli_fbase;
1601 }
1602 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1603 }
1604
1605 if (dladdr((void *)addr, &dlinfo) != 0) {
1606 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1607 }
1608
1609 return false;
1610 }
1611
1612 bool os::dll_address_to_function_name(address addr, char *buf,
1613 int buflen, int *offset,
1614 bool demangle) {
1615 // buf is not optional, but offset is optional
1616 assert(buf != NULL, "sanity check");
1617
1618 Dl_info dlinfo;
1619
1620 if (dladdr((void*)addr, &dlinfo) != 0) {
1621 // see if we have a matching symbol
1622 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1623 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1624 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1625 }
1626 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1627 return true;
1628 }
1629 // no matching symbol so try for just file info
1630 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1631 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1632 buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1633 return true;
1634 }
1635 }
1636 }
1637
1638 buf[0] = '\0';
1639 if (offset != NULL) *offset = -1;
1640 return false;
1641 }
1642
1643 struct _address_to_library_name {
1644 address addr; // input : memory address
1645 size_t buflen; // size of fname
1646 char* fname; // output: library name
1647 address base; // library base addr
1648 };
1649
1650 static int address_to_library_name_callback(struct dl_phdr_info *info,
1651 size_t size, void *data) {
1652 int i;
1653 bool found = false;
1654 address libbase = NULL;
1655 struct _address_to_library_name * d = (struct _address_to_library_name *)data;
1656
1657 // iterate through all loadable segments
1658 for (i = 0; i < info->dlpi_phnum; i++) {
1659 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
1660 if (info->dlpi_phdr[i].p_type == PT_LOAD) {
1661 // base address of a library is the lowest address of its loaded
1662 // segments.
1663 if (libbase == NULL || libbase > segbase) {
1664 libbase = segbase;
1665 }
1666 // see if 'addr' is within current segment
1667 if (segbase <= d->addr &&
1668 d->addr < segbase + info->dlpi_phdr[i].p_memsz) {
1669 found = true;
1670 }
1671 }
1672 }
1673
1674 // dlpi_name is NULL or empty if the ELF file is executable, return 0
1675 // so dll_address_to_library_name() can fall through to use dladdr() which
1676 // can figure out executable name from argv[0].
1677 if (found && info->dlpi_name && info->dlpi_name[0]) {
1678 d->base = libbase;
1679 if (d->fname) {
1680 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name);
1681 }
1682 return 1;
1683 }
1684 return 0;
1685 }
1686
1687 bool os::dll_address_to_library_name(address addr, char* buf,
1688 int buflen, int* offset) {
1689 // buf is not optional, but offset is optional
1690 assert(buf != NULL, "sanity check");
1691
1692 Dl_info dlinfo;
1693 struct _address_to_library_name data;
1694
1695 // There is a bug in old glibc dladdr() implementation that it could resolve
1696 // to wrong library name if the .so file has a base address != NULL. Here
1697 // we iterate through the program headers of all loaded libraries to find
1698 // out which library 'addr' really belongs to. This workaround can be
1699 // removed once the minimum requirement for glibc is moved to 2.3.x.
1700 data.addr = addr;
1701 data.fname = buf;
1702 data.buflen = buflen;
1703 data.base = NULL;
1704 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data);
1705
1706 if (rslt) {
1707 // buf already contains library name
1708 if (offset) *offset = addr - data.base;
1709 return true;
1710 }
1711 if (dladdr((void*)addr, &dlinfo) != 0) {
1712 if (dlinfo.dli_fname != NULL) {
1713 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1714 }
1715 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1716 *offset = addr - (address)dlinfo.dli_fbase;
1717 }
1718 return true;
1719 }
1720
1721 buf[0] = '\0';
1722 if (offset) *offset = -1;
1723 return false;
1724 }
1725
1726 // Loads .dll/.so and
1727 // in case of error it checks if .dll/.so was built for the
1728 // same architecture as Hotspot is running on
1729
1730
1731 // Remember the stack's state. The Linux dynamic linker will change
1732 // the stack to 'executable' at most once, so we must safepoint only once.
1733 bool os::Linux::_stack_is_executable = false;
1734
1735 // VM operation that loads a library. This is necessary if stack protection
1736 // of the Java stacks can be lost during loading the library. If we
1737 // do not stop the Java threads, they can stack overflow before the stacks
1738 // are protected again.
1739 class VM_LinuxDllLoad: public VM_Operation {
1740 private:
1741 const char *_filename;
1742 char *_ebuf;
1743 int _ebuflen;
1744 void *_lib;
1745 public:
1746 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) :
1747 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {}
1748 VMOp_Type type() const { return VMOp_LinuxDllLoad; }
1749 void doit() {
1750 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen);
1751 os::Linux::_stack_is_executable = true;
1752 }
1753 void* loaded_library() { return _lib; }
1754 };
1755
1756 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1757 void * result = NULL;
1758 bool load_attempted = false;
1759
1760 log_info(os)("attempting shared library load of %s", filename);
1761
1762 // Check whether the library to load might change execution rights
1763 // of the stack. If they are changed, the protection of the stack
1764 // guard pages will be lost. We need a safepoint to fix this.
1765 //
1766 // See Linux man page execstack(8) for more info.
1767 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) {
1768 if (!ElfFile::specifies_noexecstack(filename)) {
1769 if (!is_init_completed()) {
1770 os::Linux::_stack_is_executable = true;
1771 // This is OK - No Java threads have been created yet, and hence no
1772 // stack guard pages to fix.
1773 //
1774 // Dynamic loader will make all stacks executable after
1775 // this function returns, and will not do that again.
1776 assert(Threads::number_of_threads() == 0, "no Java threads should exist yet.");
1777 } else {
1778 warning("You have loaded library %s which might have disabled stack guard. "
1779 "The VM will try to fix the stack guard now.\n"
1780 "It's highly recommended that you fix the library with "
1781 "'execstack -c <libfile>', or link it with '-z noexecstack'.",
1782 filename);
1783
1784 assert(Thread::current()->is_Java_thread(), "must be Java thread");
1785 JavaThread *jt = JavaThread::current();
1786 if (jt->thread_state() != _thread_in_native) {
1787 // This happens when a compiler thread tries to load a hsdis-<arch>.so file
1788 // that requires ExecStack. Cannot enter safe point. Let's give up.
1789 warning("Unable to fix stack guard. Giving up.");
1790 } else {
1791 if (!LoadExecStackDllInVMThread) {
1792 // This is for the case where the DLL has an static
1793 // constructor function that executes JNI code. We cannot
1794 // load such DLLs in the VMThread.
1795 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1796 }
1797
1798 ThreadInVMfromNative tiv(jt);
1799 debug_only(VMNativeEntryWrapper vew;)
1800
1801 VM_LinuxDllLoad op(filename, ebuf, ebuflen);
1802 VMThread::execute(&op);
1803 if (LoadExecStackDllInVMThread) {
1804 result = op.loaded_library();
1805 }
1806 load_attempted = true;
1807 }
1808 }
1809 }
1810 }
1811
1812 if (!load_attempted) {
1813 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1814 }
1815
1816 if (result != NULL) {
1817 // Successful loading
1818 return result;
1819 }
1820
1821 Elf32_Ehdr elf_head;
1822 int diag_msg_max_length=ebuflen-strlen(ebuf);
1823 char* diag_msg_buf=ebuf+strlen(ebuf);
1824
1825 if (diag_msg_max_length==0) {
1826 // No more space in ebuf for additional diagnostics message
1827 return NULL;
1828 }
1829
1830
1831 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1832
1833 if (file_descriptor < 0) {
1834 // Can't open library, report dlerror() message
1835 return NULL;
1836 }
1837
1838 bool failed_to_read_elf_head=
1839 (sizeof(elf_head)!=
1840 (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1841
1842 ::close(file_descriptor);
1843 if (failed_to_read_elf_head) {
1844 // file i/o error - report dlerror() msg
1845 return NULL;
1846 }
1847
1848 if (elf_head.e_ident[EI_DATA] != LITTLE_ENDIAN_ONLY(ELFDATA2LSB) BIG_ENDIAN_ONLY(ELFDATA2MSB)) {
1849 // handle invalid/out of range endianness values
1850 if (elf_head.e_ident[EI_DATA] == 0 || elf_head.e_ident[EI_DATA] > 2) {
1851 return NULL;
1852 }
1853
1854 #if defined(VM_LITTLE_ENDIAN)
1855 // VM is LE, shared object BE
1856 elf_head.e_machine = be16toh(elf_head.e_machine);
1857 #else
1858 // VM is BE, shared object LE
1859 elf_head.e_machine = le16toh(elf_head.e_machine);
1860 #endif
1861 }
1862
1863 typedef struct {
1864 Elf32_Half code; // Actual value as defined in elf.h
1865 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1866 unsigned char elf_class; // 32 or 64 bit
1867 unsigned char endianness; // MSB or LSB
1868 char* name; // String representation
1869 } arch_t;
1870
1871 #ifndef EM_AARCH64
1872 #define EM_AARCH64 183 /* ARM AARCH64 */
1873 #endif
1874 #ifndef EM_RISCV
1875 #define EM_RISCV 243 /* RISC-V */
1876 #endif
1877
1878 static const arch_t arch_array[]={
1879 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1880 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1881 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1882 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1883 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1884 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1885 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1886 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1887 #if defined(VM_LITTLE_ENDIAN)
1888 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"},
1889 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"},
1890 #else
1891 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1892 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"},
1893 #endif
1894 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1895 // we only support 64 bit z architecture
1896 {EM_S390, EM_S390, ELFCLASS64, ELFDATA2MSB, (char*)"IBM System/390"},
1897 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1898 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1899 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1900 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1901 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"},
1902 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"},
1903 {EM_RISCV, EM_RISCV, ELFCLASS64, ELFDATA2LSB, (char*)"RISC-V"},
1904 };
1905
1906 #if (defined IA32)
1907 static Elf32_Half running_arch_code=EM_386;
1908 #elif (defined AMD64) || (defined X32)
1909 static Elf32_Half running_arch_code=EM_X86_64;
1910 #elif (defined IA64)
1911 static Elf32_Half running_arch_code=EM_IA_64;
1912 #elif (defined __sparc) && (defined _LP64)
1913 static Elf32_Half running_arch_code=EM_SPARCV9;
1914 #elif (defined __sparc) && (!defined _LP64)
1915 static Elf32_Half running_arch_code=EM_SPARC;
1916 #elif (defined __powerpc64__)
1917 static Elf32_Half running_arch_code=EM_PPC64;
1918 #elif (defined __powerpc__)
1919 static Elf32_Half running_arch_code=EM_PPC;
1920 #elif (defined AARCH64)
1921 static Elf32_Half running_arch_code=EM_AARCH64;
1922 #elif (defined ARM)
1923 static Elf32_Half running_arch_code=EM_ARM;
1924 #elif (defined S390)
1925 static Elf32_Half running_arch_code=EM_S390;
1926 #elif (defined ALPHA)
1927 static Elf32_Half running_arch_code=EM_ALPHA;
1928 #elif (defined MIPSEL)
1929 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1930 #elif (defined PARISC)
1931 static Elf32_Half running_arch_code=EM_PARISC;
1932 #elif (defined MIPS)
1933 static Elf32_Half running_arch_code=EM_MIPS;
1934 #elif (defined M68K)
1935 static Elf32_Half running_arch_code=EM_68K;
1936 #elif (defined SH)
1937 static Elf32_Half running_arch_code=EM_SH;
1938 #elif (defined RISCV)
1939 static Elf32_Half running_arch_code=EM_RISCV;
1940 #else
1941 #error Method os::dll_load requires that one of following is defined:\
1942 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, RISCV, S390, SH, __sparc
1943 #endif
1944
1945 // Identify compatibility class for VM's architecture and library's architecture
1946 // Obtain string descriptions for architectures
1947
1948 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1949 int running_arch_index=-1;
1950
1951 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1952 if (running_arch_code == arch_array[i].code) {
1953 running_arch_index = i;
1954 }
1955 if (lib_arch.code == arch_array[i].code) {
1956 lib_arch.compat_class = arch_array[i].compat_class;
1957 lib_arch.name = arch_array[i].name;
1958 }
1959 }
1960
1961 assert(running_arch_index != -1,
1962 "Didn't find running architecture code (running_arch_code) in arch_array");
1963 if (running_arch_index == -1) {
1964 // Even though running architecture detection failed
1965 // we may still continue with reporting dlerror() message
1966 return NULL;
1967 }
1968
1969 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1970 if (lib_arch.name != NULL) {
1971 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1972 " (Possible cause: can't load %s .so on a %s platform)",
1973 lib_arch.name, arch_array[running_arch_index].name);
1974 } else {
1975 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1976 " (Possible cause: can't load this .so (machine code=0x%x) on a %s platform)",
1977 lib_arch.code, arch_array[running_arch_index].name);
1978 }
1979 return NULL;
1980 }
1981
1982 if (lib_arch.endianness != arch_array[running_arch_index].endianness) {
1983 ::snprintf(diag_msg_buf, diag_msg_max_length-1, " (Possible cause: endianness mismatch)");
1984 return NULL;
1985 }
1986
1987 // ELF file class/capacity : 0 - invalid, 1 - 32bit, 2 - 64bit
1988 if (lib_arch.elf_class > 2 || lib_arch.elf_class < 1) {
1989 ::snprintf(diag_msg_buf, diag_msg_max_length-1, " (Possible cause: invalid ELF file class)");
1990 return NULL;
1991 }
1992
1993 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1994 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1995 " (Possible cause: architecture word width mismatch, can't load %d-bit .so on a %d-bit platform)",
1996 (int) lib_arch.elf_class * 32, arch_array[running_arch_index].elf_class * 32);
1997 return NULL;
1998 }
1999
2000 return NULL;
2001 }
2002
2003 void * os::Linux::dlopen_helper(const char *filename, char *ebuf,
2004 int ebuflen) {
2005 void * result = ::dlopen(filename, RTLD_LAZY);
2006 if (result == NULL) {
2007 const char* error_report = ::dlerror();
2008 if (error_report == NULL) {
2009 error_report = "dlerror returned no error description";
2010 }
2011 if (ebuf != NULL && ebuflen > 0) {
2012 ::strncpy(ebuf, error_report, ebuflen-1);
2013 ebuf[ebuflen-1]='\0';
2014 }
2015 Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
2016 log_info(os)("shared library load of %s failed, %s", filename, error_report);
2017 } else {
2018 Events::log(NULL, "Loaded shared library %s", filename);
2019 log_info(os)("shared library load of %s was successful", filename);
2020 }
2021 return result;
2022 }
2023
2024 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf,
2025 int ebuflen) {
2026 void * result = NULL;
2027 if (LoadExecStackDllInVMThread) {
2028 result = dlopen_helper(filename, ebuf, ebuflen);
2029 }
2030
2031 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a
2032 // library that requires an executable stack, or which does not have this
2033 // stack attribute set, dlopen changes the stack attribute to executable. The
2034 // read protection of the guard pages gets lost.
2035 //
2036 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad
2037 // may have been queued at the same time.
2038
2039 if (!_stack_is_executable) {
2040 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
2041 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized
2042 jt->stack_guards_enabled()) { // No pending stack overflow exceptions
2043 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) {
2044 warning("Attempt to reguard stack yellow zone failed.");
2045 }
2046 }
2047 }
2048 }
2049
2050 return result;
2051 }
2052
2053 void* os::dll_lookup(void* handle, const char* name) {
2054 void* res = dlsym(handle, name);
2055 return res;
2056 }
2057
2058 void* os::get_default_process_handle() {
2059 return (void*)::dlopen(NULL, RTLD_LAZY);
2060 }
2061
2062 static bool _print_ascii_file(const char* filename, outputStream* st, const char* hdr = NULL) {
2063 int fd = ::open(filename, O_RDONLY);
2064 if (fd == -1) {
2065 return false;
2066 }
2067
2068 if (hdr != NULL) {
2069 st->print_cr("%s", hdr);
2070 }
2071
2072 char buf[33];
2073 int bytes;
2074 buf[32] = '\0';
2075 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) {
2076 st->print_raw(buf, bytes);
2077 }
2078
2079 ::close(fd);
2080
2081 return true;
2082 }
2083
2084 static void _print_ascii_file_h(const char* header, const char* filename, outputStream* st, bool same_line = true) {
2085 st->print("%s:%c", header, same_line ? ' ' : '\n');
2086 if (!_print_ascii_file(filename, st)) {
2087 st->print_cr("<Not Available>");
2088 }
2089 }
2090
2091 void os::print_dll_info(outputStream *st) {
2092 st->print_cr("Dynamic libraries:");
2093
2094 char fname[32];
2095 pid_t pid = os::Linux::gettid();
2096
2097 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid);
2098
2099 if (!_print_ascii_file(fname, st)) {
2100 st->print_cr("Can not get library information for pid = %d", pid);
2101 }
2102 }
2103
2104 struct loaded_modules_info_param {
2105 os::LoadedModulesCallbackFunc callback;
2106 void *param;
2107 };
2108
2109 static int dl_iterate_callback(struct dl_phdr_info *info, size_t size, void *data) {
2110 if ((info->dlpi_name == NULL) || (*info->dlpi_name == '\0')) {
2111 return 0;
2112 }
2113
2114 struct loaded_modules_info_param *callback_param = reinterpret_cast<struct loaded_modules_info_param *>(data);
2115 address base = NULL;
2116 address top = NULL;
2117 for (int idx = 0; idx < info->dlpi_phnum; idx++) {
2118 const ElfW(Phdr) *phdr = info->dlpi_phdr + idx;
2119 if (phdr->p_type == PT_LOAD) {
2120 address raw_phdr_base = reinterpret_cast<address>(info->dlpi_addr + phdr->p_vaddr);
2121
2122 address phdr_base = align_down(raw_phdr_base, phdr->p_align);
2123 if ((base == NULL) || (base > phdr_base)) {
2124 base = phdr_base;
2125 }
2126
2127 address phdr_top = align_up(raw_phdr_base + phdr->p_memsz, phdr->p_align);
2128 if ((top == NULL) || (top < phdr_top)) {
2129 top = phdr_top;
2130 }
2131 }
2132 }
2133
2134 return callback_param->callback(info->dlpi_name, base, top, callback_param->param);
2135 }
2136
2137 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
2138 struct loaded_modules_info_param callback_param = {callback, param};
2139 return dl_iterate_phdr(&dl_iterate_callback, &callback_param);
2140 }
2141
2142 void os::print_os_info_brief(outputStream* st) {
2143 os::Linux::print_distro_info(st);
2144
2145 os::Posix::print_uname_info(st);
2146
2147 os::Linux::print_libversion_info(st);
2148
2149 }
2150
2151 void os::print_os_info(outputStream* st) {
2152 st->print_cr("OS:");
2153
2154 os::Linux::print_distro_info(st);
2155
2156 os::Posix::print_uname_info(st);
2157
2158 os::Linux::print_uptime_info(st);
2159
2160 // Print warning if unsafe chroot environment detected
2161 if (unsafe_chroot_detected) {
2162 st->print_cr("WARNING!! %s", unstable_chroot_error);
2163 }
2164
2165 os::Linux::print_libversion_info(st);
2166
2167 os::Posix::print_rlimit_info(st);
2168
2169 os::Posix::print_load_average(st);
2170 st->cr();
2171
2172 os::Linux::print_system_memory_info(st);
2173 st->cr();
2174
2175 os::Linux::print_process_memory_info(st);
2176 st->cr();
2177
2178 os::Linux::print_proc_sys_info(st);
2179 st->cr();
2180
2181 if (os::Linux::print_ld_preload_file(st)) {
2182 st->cr();
2183 }
2184
2185 if (os::Linux::print_container_info(st)) {
2186 st->cr();
2187 }
2188
2189 VM_Version::print_platform_virtualization_info(st);
2190
2191 os::Linux::print_steal_info(st);
2192 }
2193
2194 // Try to identify popular distros.
2195 // Most Linux distributions have a /etc/XXX-release file, which contains
2196 // the OS version string. Newer Linux distributions have a /etc/lsb-release
2197 // file that also contains the OS version string. Some have more than one
2198 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and
2199 // /etc/redhat-release.), so the order is important.
2200 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have
2201 // their own specific XXX-release file as well as a redhat-release file.
2202 // Because of this the XXX-release file needs to be searched for before the
2203 // redhat-release file.
2204 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the
2205 // search for redhat-release / SuSE-release needs to be before lsb-release.
2206 // Since the lsb-release file is the new standard it needs to be searched
2207 // before the older style release files.
2208 // Searching system-release (Red Hat) and os-release (other Linuxes) are a
2209 // next to last resort. The os-release file is a new standard that contains
2210 // distribution information and the system-release file seems to be an old
2211 // standard that has been replaced by the lsb-release and os-release files.
2212 // Searching for the debian_version file is the last resort. It contains
2213 // an informative string like "6.0.6" or "wheezy/sid". Because of this
2214 // "Debian " is printed before the contents of the debian_version file.
2215
2216 const char* distro_files[] = {
2217 "/etc/oracle-release",
2218 "/etc/mandriva-release",
2219 "/etc/mandrake-release",
2220 "/etc/sun-release",
2221 "/etc/redhat-release",
2222 "/etc/SuSE-release",
2223 "/etc/lsb-release",
2224 "/etc/turbolinux-release",
2225 "/etc/gentoo-release",
2226 "/etc/ltib-release",
2227 "/etc/angstrom-version",
2228 "/etc/system-release",
2229 "/etc/os-release",
2230 NULL };
2231
2232 void os::Linux::print_distro_info(outputStream* st) {
2233 for (int i = 0;; i++) {
2234 const char* file = distro_files[i];
2235 if (file == NULL) {
2236 break; // done
2237 }
2238 // If file prints, we found it.
2239 if (_print_ascii_file(file, st)) {
2240 return;
2241 }
2242 }
2243
2244 if (file_exists("/etc/debian_version")) {
2245 st->print("Debian ");
2246 _print_ascii_file("/etc/debian_version", st);
2247 } else {
2248 st->print_cr("Linux");
2249 }
2250 }
2251
2252 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) {
2253 char buf[256];
2254 while (fgets(buf, sizeof(buf), fp)) {
2255 // Edit out extra stuff in expected format
2256 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) {
2257 char* ptr = strstr(buf, "\""); // the name is in quotes
2258 if (ptr != NULL) {
2259 ptr++; // go beyond first quote
2260 char* nl = strchr(ptr, '\"');
2261 if (nl != NULL) *nl = '\0';
2262 strncpy(distro, ptr, length);
2263 } else {
2264 ptr = strstr(buf, "=");
2265 ptr++; // go beyond equals then
2266 char* nl = strchr(ptr, '\n');
2267 if (nl != NULL) *nl = '\0';
2268 strncpy(distro, ptr, length);
2269 }
2270 return;
2271 } else if (get_first_line) {
2272 char* nl = strchr(buf, '\n');
2273 if (nl != NULL) *nl = '\0';
2274 strncpy(distro, buf, length);
2275 return;
2276 }
2277 }
2278 // print last line and close
2279 char* nl = strchr(buf, '\n');
2280 if (nl != NULL) *nl = '\0';
2281 strncpy(distro, buf, length);
2282 }
2283
2284 static void parse_os_info(char* distro, size_t length, const char* file) {
2285 FILE* fp = fopen(file, "r");
2286 if (fp != NULL) {
2287 // if suse format, print out first line
2288 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0);
2289 parse_os_info_helper(fp, distro, length, get_first_line);
2290 fclose(fp);
2291 }
2292 }
2293
2294 void os::get_summary_os_info(char* buf, size_t buflen) {
2295 for (int i = 0;; i++) {
2296 const char* file = distro_files[i];
2297 if (file == NULL) {
2298 break; // ran out of distro_files
2299 }
2300 if (file_exists(file)) {
2301 parse_os_info(buf, buflen, file);
2302 return;
2303 }
2304 }
2305 // special case for debian
2306 if (file_exists("/etc/debian_version")) {
2307 strncpy(buf, "Debian ", buflen);
2308 if (buflen > 7) {
2309 parse_os_info(&buf[7], buflen-7, "/etc/debian_version");
2310 }
2311 } else {
2312 strncpy(buf, "Linux", buflen);
2313 }
2314 }
2315
2316 void os::Linux::print_libversion_info(outputStream* st) {
2317 // libc, pthread
2318 st->print("libc: ");
2319 st->print("%s ", os::Linux::glibc_version());
2320 st->print("%s ", os::Linux::libpthread_version());
2321 st->cr();
2322 }
2323
2324 void os::Linux::print_proc_sys_info(outputStream* st) {
2325 _print_ascii_file_h("/proc/sys/kernel/threads-max (system-wide limit on the number of threads)",
2326 "/proc/sys/kernel/threads-max", st);
2327 _print_ascii_file_h("/proc/sys/vm/max_map_count (maximum number of memory map areas a process may have)",
2328 "/proc/sys/vm/max_map_count", st);
2329 _print_ascii_file_h("/proc/sys/kernel/pid_max (system-wide limit on number of process identifiers)",
2330 "/proc/sys/kernel/pid_max", st);
2331 }
2332
2333 void os::Linux::print_system_memory_info(outputStream* st) {
2334 _print_ascii_file_h("/proc/meminfo", "/proc/meminfo", st, false);
2335 st->cr();
2336
2337 // some information regarding THPs; for details see
2338 // https://www.kernel.org/doc/Documentation/vm/transhuge.txt
2339 _print_ascii_file_h("/sys/kernel/mm/transparent_hugepage/enabled",
2340 "/sys/kernel/mm/transparent_hugepage/enabled", st);
2341 _print_ascii_file_h("/sys/kernel/mm/transparent_hugepage/defrag (defrag/compaction efforts parameter)",
2342 "/sys/kernel/mm/transparent_hugepage/defrag", st);
2343 }
2344
2345 void os::Linux::print_process_memory_info(outputStream* st) {
2346
2347 st->print_cr("Process Memory:");
2348
2349 // Print virtual and resident set size; peak values; swap; and for
2350 // rss its components if the kernel is recent enough.
2351 ssize_t vmsize = -1, vmpeak = -1, vmswap = -1,
2352 vmrss = -1, vmhwm = -1, rssanon = -1, rssfile = -1, rssshmem = -1;
2353 const int num_values = 8;
2354 int num_found = 0;
2355 FILE* f = ::fopen("/proc/self/status", "r");
2356 char buf[256];
2357 while (::fgets(buf, sizeof(buf), f) != NULL && num_found < num_values) {
2358 if ( (vmsize == -1 && sscanf(buf, "VmSize: " SSIZE_FORMAT " kB", &vmsize) == 1) ||
2359 (vmpeak == -1 && sscanf(buf, "VmPeak: " SSIZE_FORMAT " kB", &vmpeak) == 1) ||
2360 (vmswap == -1 && sscanf(buf, "VmSwap: " SSIZE_FORMAT " kB", &vmswap) == 1) ||
2361 (vmhwm == -1 && sscanf(buf, "VmHWM: " SSIZE_FORMAT " kB", &vmhwm) == 1) ||
2362 (vmrss == -1 && sscanf(buf, "VmRSS: " SSIZE_FORMAT " kB", &vmrss) == 1) ||
2363 (rssanon == -1 && sscanf(buf, "RssAnon: " SSIZE_FORMAT " kB", &rssanon) == 1) ||
2364 (rssfile == -1 && sscanf(buf, "RssFile: " SSIZE_FORMAT " kB", &rssfile) == 1) ||
2365 (rssshmem == -1 && sscanf(buf, "RssShmem: " SSIZE_FORMAT " kB", &rssshmem) == 1)
2366 )
2367 {
2368 num_found ++;
2369 }
2370 }
2371 st->print_cr("Virtual Size: " SSIZE_FORMAT "K (peak: " SSIZE_FORMAT "K)", vmsize, vmpeak);
2372 st->print("Resident Set Size: " SSIZE_FORMAT "K (peak: " SSIZE_FORMAT "K)", vmrss, vmhwm);
2373 if (rssanon != -1) { // requires kernel >= 4.5
2374 st->print(" (anon: " SSIZE_FORMAT "K, file: " SSIZE_FORMAT "K, shmem: " SSIZE_FORMAT "K)",
2375 rssanon, rssfile, rssshmem);
2376 }
2377 st->cr();
2378 if (vmswap != -1) { // requires kernel >= 2.6.34
2379 st->print_cr("Swapped out: " SSIZE_FORMAT "K", vmswap);
2380 }
2381
2382 // Print glibc outstanding allocations.
2383 // (note: there is no implementation of mallinfo for muslc)
2384 #ifdef __GLIBC__
2385 struct mallinfo mi = ::mallinfo();
2386
2387 // mallinfo is an old API. Member names mean next to nothing and, beyond that, are int.
2388 // So values may have wrapped around. Still useful enough to see how much glibc thinks
2389 // we allocated.
2390 const size_t total_allocated = (size_t)(unsigned)mi.uordblks;
2391 st->print("C-Heap outstanding allocations: " SIZE_FORMAT "K", total_allocated / K);
2392 // Since mallinfo members are int, glibc values may have wrapped. Warn about this.
2393 if ((vmrss * K) > UINT_MAX && (vmrss * K) > (total_allocated + UINT_MAX)) {
2394 st->print(" (may have wrapped)");
2395 }
2396 st->cr();
2397
2398 #endif // __GLIBC__
2399
2400 }
2401
2402 bool os::Linux::print_ld_preload_file(outputStream* st) {
2403 return _print_ascii_file("/etc/ld.so.preload", st, "/etc/ld.so.preload:");
2404 }
2405
2406 void os::Linux::print_uptime_info(outputStream* st) {
2407 struct sysinfo sinfo;
2408 int ret = sysinfo(&sinfo);
2409 if (ret == 0) {
2410 os::print_dhm(st, "OS uptime:", (long) sinfo.uptime);
2411 }
2412 }
2413
2414 bool os::Linux::print_container_info(outputStream* st) {
2415 if (!OSContainer::is_containerized()) {
2416 return false;
2417 }
2418
2419 st->print_cr("container (cgroup) information:");
2420
2421 const char *p_ct = OSContainer::container_type();
2422 st->print_cr("container_type: %s", p_ct != NULL ? p_ct : "not supported");
2423
2424 char *p = OSContainer::cpu_cpuset_cpus();
2425 st->print_cr("cpu_cpuset_cpus: %s", p != NULL ? p : "not supported");
2426 free(p);
2427
2428 p = OSContainer::cpu_cpuset_memory_nodes();
2429 st->print_cr("cpu_memory_nodes: %s", p != NULL ? p : "not supported");
2430 free(p);
2431
2432 int i = OSContainer::active_processor_count();
2433 st->print("active_processor_count: ");
2434 if (i > 0) {
2435 st->print_cr("%d", i);
2436 } else {
2437 st->print_cr("not supported");
2438 }
2439
2440 i = OSContainer::cpu_quota();
2441 st->print("cpu_quota: ");
2442 if (i > 0) {
2443 st->print_cr("%d", i);
2444 } else {
2445 st->print_cr("%s", i == OSCONTAINER_ERROR ? "not supported" : "no quota");
2446 }
2447
2448 i = OSContainer::cpu_period();
2449 st->print("cpu_period: ");
2450 if (i > 0) {
2451 st->print_cr("%d", i);
2452 } else {
2453 st->print_cr("%s", i == OSCONTAINER_ERROR ? "not supported" : "no period");
2454 }
2455
2456 i = OSContainer::cpu_shares();
2457 st->print("cpu_shares: ");
2458 if (i > 0) {
2459 st->print_cr("%d", i);
2460 } else {
2461 st->print_cr("%s", i == OSCONTAINER_ERROR ? "not supported" : "no shares");
2462 }
2463
2464 jlong j = OSContainer::memory_limit_in_bytes();
2465 st->print("memory_limit_in_bytes: ");
2466 if (j > 0) {
2467 st->print_cr(JLONG_FORMAT, j);
2468 } else {
2469 st->print_cr("%s", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2470 }
2471
2472 j = OSContainer::memory_and_swap_limit_in_bytes();
2473 st->print("memory_and_swap_limit_in_bytes: ");
2474 if (j > 0) {
2475 st->print_cr(JLONG_FORMAT, j);
2476 } else {
2477 st->print_cr("%s", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2478 }
2479
2480 j = OSContainer::memory_soft_limit_in_bytes();
2481 st->print("memory_soft_limit_in_bytes: ");
2482 if (j > 0) {
2483 st->print_cr(JLONG_FORMAT, j);
2484 } else {
2485 st->print_cr("%s", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2486 }
2487
2488 j = OSContainer::OSContainer::memory_usage_in_bytes();
2489 st->print("memory_usage_in_bytes: ");
2490 if (j > 0) {
2491 st->print_cr(JLONG_FORMAT, j);
2492 } else {
2493 st->print_cr("%s", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2494 }
2495
2496 j = OSContainer::OSContainer::memory_max_usage_in_bytes();
2497 st->print("memory_max_usage_in_bytes: ");
2498 if (j > 0) {
2499 st->print_cr(JLONG_FORMAT, j);
2500 } else {
2501 st->print_cr("%s", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2502 }
2503
2504 return true;
2505 }
2506
2507 void os::Linux::print_steal_info(outputStream* st) {
2508 if (has_initial_tick_info) {
2509 CPUPerfTicks pticks;
2510 bool res = os::Linux::get_tick_information(&pticks, -1);
2511
2512 if (res && pticks.has_steal_ticks) {
2513 uint64_t steal_ticks_difference = pticks.steal - initial_steal_ticks;
2514 uint64_t total_ticks_difference = pticks.total - initial_total_ticks;
2515 double steal_ticks_perc = 0.0;
2516 if (total_ticks_difference != 0) {
2517 steal_ticks_perc = (double) steal_ticks_difference / total_ticks_difference;
2518 }
2519 st->print_cr("Steal ticks since vm start: " UINT64_FORMAT, steal_ticks_difference);
2520 st->print_cr("Steal ticks percentage since vm start:%7.3f", steal_ticks_perc);
2521 }
2522 }
2523 }
2524
2525 void os::print_memory_info(outputStream* st) {
2526
2527 st->print("Memory:");
2528 st->print(" %dk page", os::vm_page_size()>>10);
2529
2530 // values in struct sysinfo are "unsigned long"
2531 struct sysinfo si;
2532 sysinfo(&si);
2533
2534 st->print(", physical " UINT64_FORMAT "k",
2535 os::physical_memory() >> 10);
2536 st->print("(" UINT64_FORMAT "k free)",
2537 os::available_memory() >> 10);
2538 st->print(", swap " UINT64_FORMAT "k",
2539 ((jlong)si.totalswap * si.mem_unit) >> 10);
2540 st->print("(" UINT64_FORMAT "k free)",
2541 ((jlong)si.freeswap * si.mem_unit) >> 10);
2542 st->cr();
2543 }
2544
2545 // Print the first "model name" line and the first "flags" line
2546 // that we find and nothing more. We assume "model name" comes
2547 // before "flags" so if we find a second "model name", then the
2548 // "flags" field is considered missing.
2549 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) {
2550 #if defined(IA32) || defined(AMD64)
2551 // Other platforms have less repetitive cpuinfo files
2552 FILE *fp = fopen("/proc/cpuinfo", "r");
2553 if (fp) {
2554 while (!feof(fp)) {
2555 if (fgets(buf, buflen, fp)) {
2556 // Assume model name comes before flags
2557 bool model_name_printed = false;
2558 if (strstr(buf, "model name") != NULL) {
2559 if (!model_name_printed) {
2560 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n");
2561 st->print_raw(buf);
2562 model_name_printed = true;
2563 } else {
2564 // model name printed but not flags? Odd, just return
2565 fclose(fp);
2566 return true;
2567 }
2568 }
2569 // print the flags line too
2570 if (strstr(buf, "flags") != NULL) {
2571 st->print_raw(buf);
2572 fclose(fp);
2573 return true;
2574 }
2575 }
2576 }
2577 fclose(fp);
2578 }
2579 #endif // x86 platforms
2580 return false;
2581 }
2582
2583 // additional information about CPU e.g. available frequency ranges
2584 static void print_sys_devices_cpu_info(outputStream* st, char* buf, size_t buflen) {
2585 _print_ascii_file_h("Online cpus", "/sys/devices/system/cpu/online", st);
2586 _print_ascii_file_h("Offline cpus", "/sys/devices/system/cpu/offline", st);
2587
2588 if (ExtensiveErrorReports) {
2589 // cache related info (cpu 0, should be similar for other CPUs)
2590 for (unsigned int i=0; i < 10; i++) { // handle max. 10 cache entries
2591 char hbuf_level[60];
2592 char hbuf_type[60];
2593 char hbuf_size[60];
2594 char hbuf_coherency_line_size[80];
2595 snprintf(hbuf_level, 60, "/sys/devices/system/cpu/cpu0/cache/index%u/level", i);
2596 snprintf(hbuf_type, 60, "/sys/devices/system/cpu/cpu0/cache/index%u/type", i);
2597 snprintf(hbuf_size, 60, "/sys/devices/system/cpu/cpu0/cache/index%u/size", i);
2598 snprintf(hbuf_coherency_line_size, 80, "/sys/devices/system/cpu/cpu0/cache/index%u/coherency_line_size", i);
2599 if (file_exists(hbuf_level)) {
2600 _print_ascii_file_h("cache level", hbuf_level, st);
2601 _print_ascii_file_h("cache type", hbuf_type, st);
2602 _print_ascii_file_h("cache size", hbuf_size, st);
2603 _print_ascii_file_h("cache coherency line size", hbuf_coherency_line_size, st);
2604 }
2605 }
2606 }
2607
2608 // we miss the cpufreq entries on Power and s390x
2609 #if defined(IA32) || defined(AMD64)
2610 _print_ascii_file_h("BIOS frequency limitation", "/sys/devices/system/cpu/cpu0/cpufreq/bios_limit", st);
2611 _print_ascii_file_h("Frequency switch latency (ns)", "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_transition_latency", st);
2612 _print_ascii_file_h("Available cpu frequencies", "/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies", st);
2613 // min and max should be in the Available range but still print them (not all info might be available for all kernels)
2614 if (ExtensiveErrorReports) {
2615 _print_ascii_file_h("Maximum cpu frequency", "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq", st);
2616 _print_ascii_file_h("Minimum cpu frequency", "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq", st);
2617 _print_ascii_file_h("Current cpu frequency", "/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq", st);
2618 }
2619 // governors are power schemes, see https://wiki.archlinux.org/index.php/CPU_frequency_scaling
2620 if (ExtensiveErrorReports) {
2621 _print_ascii_file_h("Available governors", "/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors", st);
2622 }
2623 _print_ascii_file_h("Current governor", "/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor", st);
2624 // Core performance boost, see https://www.kernel.org/doc/Documentation/cpu-freq/boost.txt
2625 // Raise operating frequency of some cores in a multi-core package if certain conditions apply, e.g.
2626 // whole chip is not fully utilized
2627 _print_ascii_file_h("Core performance/turbo boost", "/sys/devices/system/cpu/cpufreq/boost", st);
2628 #endif
2629 }
2630
2631 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
2632 // Only print the model name if the platform provides this as a summary
2633 if (!print_model_name_and_flags(st, buf, buflen)) {
2634 _print_ascii_file_h("/proc/cpuinfo", "/proc/cpuinfo", st, false);
2635 }
2636 st->cr();
2637 print_sys_devices_cpu_info(st, buf, buflen);
2638 }
2639
2640 #if defined(AMD64) || defined(IA32) || defined(X32)
2641 const char* search_string = "model name";
2642 #elif defined(M68K)
2643 const char* search_string = "CPU";
2644 #elif defined(PPC64)
2645 const char* search_string = "cpu";
2646 #elif defined(S390)
2647 const char* search_string = "machine =";
2648 #elif defined(SPARC)
2649 const char* search_string = "cpu";
2650 #else
2651 const char* search_string = "Processor";
2652 #endif
2653
2654 // Parses the cpuinfo file for string representing the model name.
2655 void os::get_summary_cpu_info(char* cpuinfo, size_t length) {
2656 FILE* fp = fopen("/proc/cpuinfo", "r");
2657 if (fp != NULL) {
2658 while (!feof(fp)) {
2659 char buf[256];
2660 if (fgets(buf, sizeof(buf), fp)) {
2661 char* start = strstr(buf, search_string);
2662 if (start != NULL) {
2663 char *ptr = start + strlen(search_string);
2664 char *end = buf + strlen(buf);
2665 while (ptr != end) {
2666 // skip whitespace and colon for the rest of the name.
2667 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') {
2668 break;
2669 }
2670 ptr++;
2671 }
2672 if (ptr != end) {
2673 // reasonable string, get rid of newline and keep the rest
2674 char* nl = strchr(buf, '\n');
2675 if (nl != NULL) *nl = '\0';
2676 strncpy(cpuinfo, ptr, length);
2677 fclose(fp);
2678 return;
2679 }
2680 }
2681 }
2682 }
2683 fclose(fp);
2684 }
2685 // cpuinfo not found or parsing failed, just print generic string. The entire
2686 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86)
2687 #if defined(AARCH64)
2688 strncpy(cpuinfo, "AArch64", length);
2689 #elif defined(AMD64)
2690 strncpy(cpuinfo, "x86_64", length);
2691 #elif defined(ARM) // Order wrt. AARCH64 is relevant!
2692 strncpy(cpuinfo, "ARM", length);
2693 #elif defined(IA32)
2694 strncpy(cpuinfo, "x86_32", length);
2695 #elif defined(IA64)
2696 strncpy(cpuinfo, "IA64", length);
2697 #elif defined(PPC)
2698 strncpy(cpuinfo, "PPC64", length);
2699 #elif defined(S390)
2700 strncpy(cpuinfo, "S390", length);
2701 #elif defined(SPARC)
2702 strncpy(cpuinfo, "sparcv9", length);
2703 #elif defined(ZERO_LIBARCH)
2704 strncpy(cpuinfo, ZERO_LIBARCH, length);
2705 #else
2706 strncpy(cpuinfo, "unknown", length);
2707 #endif
2708 }
2709
2710 static void print_signal_handler(outputStream* st, int sig,
2711 char* buf, size_t buflen);
2712
2713 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
2714 st->print_cr("Signal Handlers:");
2715 print_signal_handler(st, SIGSEGV, buf, buflen);
2716 print_signal_handler(st, SIGBUS , buf, buflen);
2717 print_signal_handler(st, SIGFPE , buf, buflen);
2718 print_signal_handler(st, SIGPIPE, buf, buflen);
2719 print_signal_handler(st, SIGXFSZ, buf, buflen);
2720 print_signal_handler(st, SIGILL , buf, buflen);
2721 print_signal_handler(st, SR_signum, buf, buflen);
2722 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
2723 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
2724 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
2725 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
2726 #if defined(PPC64)
2727 print_signal_handler(st, SIGTRAP, buf, buflen);
2728 #endif
2729 }
2730
2731 static char saved_jvm_path[MAXPATHLEN] = {0};
2732
2733 // Find the full path to the current module, libjvm.so
2734 void os::jvm_path(char *buf, jint buflen) {
2735 // Error checking.
2736 if (buflen < MAXPATHLEN) {
2737 assert(false, "must use a large-enough buffer");
2738 buf[0] = '\0';
2739 return;
2740 }
2741 // Lazy resolve the path to current module.
2742 if (saved_jvm_path[0] != 0) {
2743 strcpy(buf, saved_jvm_path);
2744 return;
2745 }
2746
2747 char dli_fname[MAXPATHLEN];
2748 bool ret = dll_address_to_library_name(
2749 CAST_FROM_FN_PTR(address, os::jvm_path),
2750 dli_fname, sizeof(dli_fname), NULL);
2751 assert(ret, "cannot locate libjvm");
2752 char *rp = NULL;
2753 if (ret && dli_fname[0] != '\0') {
2754 rp = os::Posix::realpath(dli_fname, buf, buflen);
2755 }
2756 if (rp == NULL) {
2757 return;
2758 }
2759
2760 if (Arguments::sun_java_launcher_is_altjvm()) {
2761 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
2762 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
2763 // If "/jre/lib/" appears at the right place in the string, then
2764 // assume we are installed in a JDK and we're done. Otherwise, check
2765 // for a JAVA_HOME environment variable and fix up the path so it
2766 // looks like libjvm.so is installed there (append a fake suffix
2767 // hotspot/libjvm.so).
2768 const char *p = buf + strlen(buf) - 1;
2769 for (int count = 0; p > buf && count < 5; ++count) {
2770 for (--p; p > buf && *p != '/'; --p)
2771 /* empty */ ;
2772 }
2773
2774 if (strncmp(p, "/jre/lib/", 9) != 0) {
2775 // Look for JAVA_HOME in the environment.
2776 char* java_home_var = ::getenv("JAVA_HOME");
2777 if (java_home_var != NULL && java_home_var[0] != 0) {
2778 char* jrelib_p;
2779 int len;
2780
2781 // Check the current module name "libjvm.so".
2782 p = strrchr(buf, '/');
2783 if (p == NULL) {
2784 return;
2785 }
2786 assert(strstr(p, "/libjvm") == p, "invalid library name");
2787
2788 rp = os::Posix::realpath(java_home_var, buf, buflen);
2789 if (rp == NULL) {
2790 return;
2791 }
2792
2793 // determine if this is a legacy image or modules image
2794 // modules image doesn't have "jre" subdirectory
2795 len = strlen(buf);
2796 assert(len < buflen, "Ran out of buffer room");
2797 jrelib_p = buf + len;
2798 snprintf(jrelib_p, buflen-len, "/jre/lib");
2799 if (0 != access(buf, F_OK)) {
2800 snprintf(jrelib_p, buflen-len, "/lib");
2801 }
2802
2803 if (0 == access(buf, F_OK)) {
2804 // Use current module name "libjvm.so"
2805 len = strlen(buf);
2806 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
2807 } else {
2808 // Go back to path of .so
2809 rp = os::Posix::realpath(dli_fname, buf, buflen);
2810 if (rp == NULL) {
2811 return;
2812 }
2813 }
2814 }
2815 }
2816 }
2817
2818 strncpy(saved_jvm_path, buf, MAXPATHLEN);
2819 saved_jvm_path[MAXPATHLEN - 1] = '\0';
2820 }
2821
2822 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
2823 // no prefix required, not even "_"
2824 }
2825
2826 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
2827 // no suffix required
2828 }
2829
2830 ////////////////////////////////////////////////////////////////////////////////
2831 // sun.misc.Signal support
2832
2833 static void UserHandler(int sig, void *siginfo, void *context) {
2834 // Ctrl-C is pressed during error reporting, likely because the error
2835 // handler fails to abort. Let VM die immediately.
2836 if (sig == SIGINT && VMError::is_error_reported()) {
2837 os::die();
2838 }
2839
2840 os::signal_notify(sig);
2841 }
2842
2843 void* os::user_handler() {
2844 return CAST_FROM_FN_PTR(void*, UserHandler);
2845 }
2846
2847 extern "C" {
2848 typedef void (*sa_handler_t)(int);
2849 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
2850 }
2851
2852 void* os::signal(int signal_number, void* handler) {
2853 struct sigaction sigAct, oldSigAct;
2854
2855 sigfillset(&(sigAct.sa_mask));
2856 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
2857 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
2858
2859 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
2860 // -1 means registration failed
2861 return (void *)-1;
2862 }
2863
2864 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
2865 }
2866
2867 void os::signal_raise(int signal_number) {
2868 ::raise(signal_number);
2869 }
2870
2871 // The following code is moved from os.cpp for making this
2872 // code platform specific, which it is by its very nature.
2873
2874 // Will be modified when max signal is changed to be dynamic
2875 int os::sigexitnum_pd() {
2876 return NSIG;
2877 }
2878
2879 // a counter for each possible signal value
2880 static volatile jint pending_signals[NSIG+1] = { 0 };
2881
2882 // Linux(POSIX) specific hand shaking semaphore.
2883 static Semaphore* sig_sem = NULL;
2884 static PosixSemaphore sr_semaphore;
2885
2886 static void jdk_misc_signal_init() {
2887 // Initialize signal structures
2888 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2889
2890 // Initialize signal semaphore
2891 sig_sem = new Semaphore();
2892 }
2893
2894 void os::signal_notify(int sig) {
2895 if (sig_sem != NULL) {
2896 Atomic::inc(&pending_signals[sig]);
2897 sig_sem->signal();
2898 } else {
2899 // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
2900 // initialization isn't called.
2901 assert(ReduceSignalUsage, "signal semaphore should be created");
2902 }
2903 }
2904
2905 static int check_pending_signals() {
2906 for (;;) {
2907 for (int i = 0; i < NSIG + 1; i++) {
2908 jint n = pending_signals[i];
2909 if (n > 0 && n == Atomic::cmpxchg(&pending_signals[i], n, n - 1)) {
2910 return i;
2911 }
2912 }
2913 JavaThread *thread = JavaThread::current();
2914 ThreadBlockInVM tbivm(thread);
2915
2916 bool threadIsSuspended;
2917 do {
2918 thread->set_suspend_equivalent();
2919 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2920 sig_sem->wait();
2921
2922 // were we externally suspended while we were waiting?
2923 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2924 if (threadIsSuspended) {
2925 // The semaphore has been incremented, but while we were waiting
2926 // another thread suspended us. We don't want to continue running
2927 // while suspended because that would surprise the thread that
2928 // suspended us.
2929 sig_sem->signal();
2930
2931 thread->java_suspend_self();
2932 }
2933 } while (threadIsSuspended);
2934 }
2935 }
2936
2937 int os::signal_wait() {
2938 return check_pending_signals();
2939 }
2940
2941 ////////////////////////////////////////////////////////////////////////////////
2942 // Virtual Memory
2943
2944 int os::vm_page_size() {
2945 // Seems redundant as all get out
2946 assert(os::Linux::page_size() != -1, "must call os::init");
2947 return os::Linux::page_size();
2948 }
2949
2950 // Solaris allocates memory by pages.
2951 int os::vm_allocation_granularity() {
2952 assert(os::Linux::page_size() != -1, "must call os::init");
2953 return os::Linux::page_size();
2954 }
2955
2956 // Rationale behind this function:
2957 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2958 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2959 // samples for JITted code. Here we create private executable mapping over the code cache
2960 // and then we can use standard (well, almost, as mapping can change) way to provide
2961 // info for the reporting script by storing timestamp and location of symbol
2962 void linux_wrap_code(char* base, size_t size) {
2963 static volatile jint cnt = 0;
2964
2965 if (!UseOprofile) {
2966 return;
2967 }
2968
2969 char buf[PATH_MAX+1];
2970 int num = Atomic::add(&cnt, 1);
2971
2972 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d",
2973 os::get_temp_directory(), os::current_process_id(), num);
2974 unlink(buf);
2975
2976 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2977
2978 if (fd != -1) {
2979 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2980 if (rv != (off_t)-1) {
2981 if (::write(fd, "", 1) == 1) {
2982 mmap(base, size,
2983 PROT_READ|PROT_WRITE|PROT_EXEC,
2984 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2985 }
2986 }
2987 ::close(fd);
2988 unlink(buf);
2989 }
2990 }
2991
2992 static bool recoverable_mmap_error(int err) {
2993 // See if the error is one we can let the caller handle. This
2994 // list of errno values comes from JBS-6843484. I can't find a
2995 // Linux man page that documents this specific set of errno
2996 // values so while this list currently matches Solaris, it may
2997 // change as we gain experience with this failure mode.
2998 switch (err) {
2999 case EBADF:
3000 case EINVAL:
3001 case ENOTSUP:
3002 // let the caller deal with these errors
3003 return true;
3004
3005 default:
3006 // Any remaining errors on this OS can cause our reserved mapping
3007 // to be lost. That can cause confusion where different data
3008 // structures think they have the same memory mapped. The worst
3009 // scenario is if both the VM and a library think they have the
3010 // same memory mapped.
3011 return false;
3012 }
3013 }
3014
3015 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
3016 int err) {
3017 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
3018 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
3019 os::strerror(err), err);
3020 }
3021
3022 static void warn_fail_commit_memory(char* addr, size_t size,
3023 size_t alignment_hint, bool exec,
3024 int err) {
3025 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
3026 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size,
3027 alignment_hint, exec, os::strerror(err), err);
3028 }
3029
3030 // NOTE: Linux kernel does not really reserve the pages for us.
3031 // All it does is to check if there are enough free pages
3032 // left at the time of mmap(). This could be a potential
3033 // problem.
3034 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) {
3035 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
3036 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
3037 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
3038 if (res != (uintptr_t) MAP_FAILED) {
3039 if (UseNUMAInterleaving) {
3040 numa_make_global(addr, size);
3041 }
3042 return 0;
3043 }
3044
3045 int err = errno; // save errno from mmap() call above
3046
3047 if (!recoverable_mmap_error(err)) {
3048 warn_fail_commit_memory(addr, size, exec, err);
3049 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory.");
3050 }
3051
3052 return err;
3053 }
3054
3055 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
3056 return os::Linux::commit_memory_impl(addr, size, exec) == 0;
3057 }
3058
3059 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
3060 const char* mesg) {
3061 assert(mesg != NULL, "mesg must be specified");
3062 int err = os::Linux::commit_memory_impl(addr, size, exec);
3063 if (err != 0) {
3064 // the caller wants all commit errors to exit with the specified mesg:
3065 warn_fail_commit_memory(addr, size, exec, err);
3066 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
3067 }
3068 }
3069
3070 // Define MAP_HUGETLB here so we can build HotSpot on old systems.
3071 #ifndef MAP_HUGETLB
3072 #define MAP_HUGETLB 0x40000
3073 #endif
3074
3075 // If mmap flags are set with MAP_HUGETLB and the system supports multiple
3076 // huge page sizes, flag bits [26:31] can be used to encode the log2 of the
3077 // desired huge page size. Otherwise, the system's default huge page size will be used.
3078 // See mmap(2) man page for more info (since Linux 3.8).
3079 // https://lwn.net/Articles/533499/
3080 #ifndef MAP_HUGE_SHIFT
3081 #define MAP_HUGE_SHIFT 26
3082 #endif
3083
3084 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems.
3085 #ifndef MADV_HUGEPAGE
3086 #define MADV_HUGEPAGE 14
3087 #endif
3088
3089 int os::Linux::commit_memory_impl(char* addr, size_t size,
3090 size_t alignment_hint, bool exec) {
3091 int err = os::Linux::commit_memory_impl(addr, size, exec);
3092 if (err == 0) {
3093 realign_memory(addr, size, alignment_hint);
3094 }
3095 return err;
3096 }
3097
3098 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
3099 bool exec) {
3100 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0;
3101 }
3102
3103 void os::pd_commit_memory_or_exit(char* addr, size_t size,
3104 size_t alignment_hint, bool exec,
3105 const char* mesg) {
3106 assert(mesg != NULL, "mesg must be specified");
3107 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec);
3108 if (err != 0) {
3109 // the caller wants all commit errors to exit with the specified mesg:
3110 warn_fail_commit_memory(addr, size, alignment_hint, exec, err);
3111 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
3112 }
3113 }
3114
3115 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
3116 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) {
3117 // We don't check the return value: madvise(MADV_HUGEPAGE) may not
3118 // be supported or the memory may already be backed by huge pages.
3119 ::madvise(addr, bytes, MADV_HUGEPAGE);
3120 }
3121 }
3122
3123 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
3124 // This method works by doing an mmap over an existing mmaping and effectively discarding
3125 // the existing pages. However it won't work for SHM-based large pages that cannot be
3126 // uncommitted at all. We don't do anything in this case to avoid creating a segment with
3127 // small pages on top of the SHM segment. This method always works for small pages, so we
3128 // allow that in any case.
3129 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) {
3130 commit_memory(addr, bytes, alignment_hint, !ExecMem);
3131 }
3132 }
3133
3134 void os::numa_make_global(char *addr, size_t bytes) {
3135 Linux::numa_interleave_memory(addr, bytes);
3136 }
3137
3138 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the
3139 // bind policy to MPOL_PREFERRED for the current thread.
3140 #define USE_MPOL_PREFERRED 0
3141
3142 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
3143 // To make NUMA and large pages more robust when both enabled, we need to ease
3144 // the requirements on where the memory should be allocated. MPOL_BIND is the
3145 // default policy and it will force memory to be allocated on the specified
3146 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on
3147 // the specified node, but will not force it. Using this policy will prevent
3148 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no
3149 // free large pages.
3150 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED);
3151 Linux::numa_tonode_memory(addr, bytes, lgrp_hint);
3152 }
3153
3154 bool os::numa_topology_changed() { return false; }
3155
3156 size_t os::numa_get_groups_num() {
3157 // Return just the number of nodes in which it's possible to allocate memory
3158 // (in numa terminology, configured nodes).
3159 return Linux::numa_num_configured_nodes();
3160 }
3161
3162 int os::numa_get_group_id() {
3163 int cpu_id = Linux::sched_getcpu();
3164 if (cpu_id != -1) {
3165 int lgrp_id = Linux::get_node_by_cpu(cpu_id);
3166 if (lgrp_id != -1) {
3167 return lgrp_id;
3168 }
3169 }
3170 return 0;
3171 }
3172
3173 int os::numa_get_group_id_for_address(const void* address) {
3174 void** pages = const_cast<void**>(&address);
3175 int id = -1;
3176
3177 if (os::Linux::numa_move_pages(0, 1, pages, NULL, &id, 0) == -1) {
3178 return -1;
3179 }
3180 if (id < 0) {
3181 return -1;
3182 }
3183 return id;
3184 }
3185
3186 int os::Linux::get_existing_num_nodes() {
3187 int node;
3188 int highest_node_number = Linux::numa_max_node();
3189 int num_nodes = 0;
3190
3191 // Get the total number of nodes in the system including nodes without memory.
3192 for (node = 0; node <= highest_node_number; node++) {
3193 if (is_node_in_existing_nodes(node)) {
3194 num_nodes++;
3195 }
3196 }
3197 return num_nodes;
3198 }
3199
3200 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
3201 int highest_node_number = Linux::numa_max_node();
3202 size_t i = 0;
3203
3204 // Map all node ids in which it is possible to allocate memory. Also nodes are
3205 // not always consecutively available, i.e. available from 0 to the highest
3206 // node number. If the nodes have been bound explicitly using numactl membind,
3207 // then allocate memory from those nodes only.
3208 for (int node = 0; node <= highest_node_number; node++) {
3209 if (Linux::is_node_in_bound_nodes((unsigned int)node)) {
3210 ids[i++] = node;
3211 }
3212 }
3213 return i;
3214 }
3215
3216 bool os::get_page_info(char *start, page_info* info) {
3217 return false;
3218 }
3219
3220 char *os::scan_pages(char *start, char* end, page_info* page_expected,
3221 page_info* page_found) {
3222 return end;
3223 }
3224
3225
3226 int os::Linux::sched_getcpu_syscall(void) {
3227 unsigned int cpu = 0;
3228 int retval = -1;
3229
3230 #if defined(IA32)
3231 #ifndef SYS_getcpu
3232 #define SYS_getcpu 318
3233 #endif
3234 retval = syscall(SYS_getcpu, &cpu, NULL, NULL);
3235 #elif defined(AMD64)
3236 // Unfortunately we have to bring all these macros here from vsyscall.h
3237 // to be able to compile on old linuxes.
3238 #define __NR_vgetcpu 2
3239 #define VSYSCALL_START (-10UL << 20)
3240 #define VSYSCALL_SIZE 1024
3241 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
3242 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache);
3243 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu);
3244 retval = vgetcpu(&cpu, NULL, NULL);
3245 #endif
3246
3247 return (retval == -1) ? retval : cpu;
3248 }
3249
3250 void os::Linux::sched_getcpu_init() {
3251 // sched_getcpu() should be in libc.
3252 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
3253 dlsym(RTLD_DEFAULT, "sched_getcpu")));
3254
3255 // If it's not, try a direct syscall.
3256 if (sched_getcpu() == -1) {
3257 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
3258 (void*)&sched_getcpu_syscall));
3259 }
3260
3261 if (sched_getcpu() == -1) {
3262 vm_exit_during_initialization("getcpu(2) system call not supported by kernel");
3263 }
3264 }
3265
3266 // Something to do with the numa-aware allocator needs these symbols
3267 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { }
3268 extern "C" JNIEXPORT void numa_error(char *where) { }
3269
3270 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails
3271 // load symbol from base version instead.
3272 void* os::Linux::libnuma_dlsym(void* handle, const char *name) {
3273 void *f = dlvsym(handle, name, "libnuma_1.1");
3274 if (f == NULL) {
3275 f = dlsym(handle, name);
3276 }
3277 return f;
3278 }
3279
3280 // Handle request to load libnuma symbol version 1.2 (API v2) only.
3281 // Return NULL if the symbol is not defined in this particular version.
3282 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) {
3283 return dlvsym(handle, name, "libnuma_1.2");
3284 }
3285
3286 bool os::Linux::libnuma_init() {
3287 if (sched_getcpu() != -1) { // Requires sched_getcpu() support
3288 void *handle = dlopen("libnuma.so.1", RTLD_LAZY);
3289 if (handle != NULL) {
3290 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t,
3291 libnuma_dlsym(handle, "numa_node_to_cpus")));
3292 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t,
3293 libnuma_dlsym(handle, "numa_max_node")));
3294 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t,
3295 libnuma_dlsym(handle, "numa_num_configured_nodes")));
3296 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t,
3297 libnuma_dlsym(handle, "numa_available")));
3298 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t,
3299 libnuma_dlsym(handle, "numa_tonode_memory")));
3300 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t,
3301 libnuma_dlsym(handle, "numa_interleave_memory")));
3302 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t,
3303 libnuma_v2_dlsym(handle, "numa_interleave_memory")));
3304 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t,
3305 libnuma_dlsym(handle, "numa_set_bind_policy")));
3306 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t,
3307 libnuma_dlsym(handle, "numa_bitmask_isbitset")));
3308 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t,
3309 libnuma_dlsym(handle, "numa_distance")));
3310 set_numa_get_membind(CAST_TO_FN_PTR(numa_get_membind_func_t,
3311 libnuma_v2_dlsym(handle, "numa_get_membind")));
3312 set_numa_get_interleave_mask(CAST_TO_FN_PTR(numa_get_interleave_mask_func_t,
3313 libnuma_v2_dlsym(handle, "numa_get_interleave_mask")));
3314 set_numa_move_pages(CAST_TO_FN_PTR(numa_move_pages_func_t,
3315 libnuma_dlsym(handle, "numa_move_pages")));
3316 set_numa_set_preferred(CAST_TO_FN_PTR(numa_set_preferred_func_t,
3317 libnuma_dlsym(handle, "numa_set_preferred")));
3318
3319 if (numa_available() != -1) {
3320 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes"));
3321 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr"));
3322 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr"));
3323 set_numa_interleave_bitmask(_numa_get_interleave_mask());
3324 set_numa_membind_bitmask(_numa_get_membind());
3325 // Create an index -> node mapping, since nodes are not always consecutive
3326 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, mtInternal);
3327 rebuild_nindex_to_node_map();
3328 // Create a cpu -> node mapping
3329 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, mtInternal);
3330 rebuild_cpu_to_node_map();
3331 return true;
3332 }
3333 }
3334 }
3335 return false;
3336 }
3337
3338 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
3339 // Creating guard page is very expensive. Java thread has HotSpot
3340 // guard pages, only enable glibc guard page for non-Java threads.
3341 // (Remember: compiler thread is a Java thread, too!)
3342 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size());
3343 }
3344
3345 void os::Linux::rebuild_nindex_to_node_map() {
3346 int highest_node_number = Linux::numa_max_node();
3347
3348 nindex_to_node()->clear();
3349 for (int node = 0; node <= highest_node_number; node++) {
3350 if (Linux::is_node_in_existing_nodes(node)) {
3351 nindex_to_node()->append(node);
3352 }
3353 }
3354 }
3355
3356 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id.
3357 // The table is later used in get_node_by_cpu().
3358 void os::Linux::rebuild_cpu_to_node_map() {
3359 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure
3360 // in libnuma (possible values are starting from 16,
3361 // and continuing up with every other power of 2, but less
3362 // than the maximum number of CPUs supported by kernel), and
3363 // is a subject to change (in libnuma version 2 the requirements
3364 // are more reasonable) we'll just hardcode the number they use
3365 // in the library.
3366 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT;
3367
3368 size_t cpu_num = processor_count();
3369 size_t cpu_map_size = NCPUS / BitsPerCLong;
3370 size_t cpu_map_valid_size =
3371 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size);
3372
3373 cpu_to_node()->clear();
3374 cpu_to_node()->at_grow(cpu_num - 1);
3375
3376 size_t node_num = get_existing_num_nodes();
3377
3378 int distance = 0;
3379 int closest_distance = INT_MAX;
3380 int closest_node = 0;
3381 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal);
3382 for (size_t i = 0; i < node_num; i++) {
3383 // Check if node is configured (not a memory-less node). If it is not, find
3384 // the closest configured node. Check also if node is bound, i.e. it's allowed
3385 // to allocate memory from the node. If it's not allowed, map cpus in that node
3386 // to the closest node from which memory allocation is allowed.
3387 if (!is_node_in_configured_nodes(nindex_to_node()->at(i)) ||
3388 !is_node_in_bound_nodes(nindex_to_node()->at(i))) {
3389 closest_distance = INT_MAX;
3390 // Check distance from all remaining nodes in the system. Ignore distance
3391 // from itself, from another non-configured node, and from another non-bound
3392 // node.
3393 for (size_t m = 0; m < node_num; m++) {
3394 if (m != i &&
3395 is_node_in_configured_nodes(nindex_to_node()->at(m)) &&
3396 is_node_in_bound_nodes(nindex_to_node()->at(m))) {
3397 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m));
3398 // If a closest node is found, update. There is always at least one
3399 // configured and bound node in the system so there is always at least
3400 // one node close.
3401 if (distance != 0 && distance < closest_distance) {
3402 closest_distance = distance;
3403 closest_node = nindex_to_node()->at(m);
3404 }
3405 }
3406 }
3407 } else {
3408 // Current node is already a configured node.
3409 closest_node = nindex_to_node()->at(i);
3410 }
3411
3412 // Get cpus from the original node and map them to the closest node. If node
3413 // is a configured node (not a memory-less node), then original node and
3414 // closest node are the same.
3415 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) {
3416 for (size_t j = 0; j < cpu_map_valid_size; j++) {
3417 if (cpu_map[j] != 0) {
3418 for (size_t k = 0; k < BitsPerCLong; k++) {
3419 if (cpu_map[j] & (1UL << k)) {
3420 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node);
3421 }
3422 }
3423 }
3424 }
3425 }
3426 }
3427 FREE_C_HEAP_ARRAY(unsigned long, cpu_map);
3428 }
3429
3430 int os::Linux::get_node_by_cpu(int cpu_id) {
3431 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) {
3432 return cpu_to_node()->at(cpu_id);
3433 }
3434 return -1;
3435 }
3436
3437 GrowableArray<int>* os::Linux::_cpu_to_node;
3438 GrowableArray<int>* os::Linux::_nindex_to_node;
3439 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu;
3440 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus;
3441 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node;
3442 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes;
3443 os::Linux::numa_available_func_t os::Linux::_numa_available;
3444 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory;
3445 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory;
3446 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2;
3447 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy;
3448 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset;
3449 os::Linux::numa_distance_func_t os::Linux::_numa_distance;
3450 os::Linux::numa_get_membind_func_t os::Linux::_numa_get_membind;
3451 os::Linux::numa_get_interleave_mask_func_t os::Linux::_numa_get_interleave_mask;
3452 os::Linux::numa_move_pages_func_t os::Linux::_numa_move_pages;
3453 os::Linux::numa_set_preferred_func_t os::Linux::_numa_set_preferred;
3454 os::Linux::NumaAllocationPolicy os::Linux::_current_numa_policy;
3455 unsigned long* os::Linux::_numa_all_nodes;
3456 struct bitmask* os::Linux::_numa_all_nodes_ptr;
3457 struct bitmask* os::Linux::_numa_nodes_ptr;
3458 struct bitmask* os::Linux::_numa_interleave_bitmask;
3459 struct bitmask* os::Linux::_numa_membind_bitmask;
3460
3461 bool os::pd_uncommit_memory(char* addr, size_t size) {
3462 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
3463 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
3464 return res != (uintptr_t) MAP_FAILED;
3465 }
3466
3467 static address get_stack_commited_bottom(address bottom, size_t size) {
3468 address nbot = bottom;
3469 address ntop = bottom + size;
3470
3471 size_t page_sz = os::vm_page_size();
3472 unsigned pages = size / page_sz;
3473
3474 unsigned char vec[1];
3475 unsigned imin = 1, imax = pages + 1, imid;
3476 int mincore_return_value = 0;
3477
3478 assert(imin <= imax, "Unexpected page size");
3479
3480 while (imin < imax) {
3481 imid = (imax + imin) / 2;
3482 nbot = ntop - (imid * page_sz);
3483
3484 // Use a trick with mincore to check whether the page is mapped or not.
3485 // mincore sets vec to 1 if page resides in memory and to 0 if page
3486 // is swapped output but if page we are asking for is unmapped
3487 // it returns -1,ENOMEM
3488 mincore_return_value = mincore(nbot, page_sz, vec);
3489
3490 if (mincore_return_value == -1) {
3491 // Page is not mapped go up
3492 // to find first mapped page
3493 if (errno != EAGAIN) {
3494 assert(errno == ENOMEM, "Unexpected mincore errno");
3495 imax = imid;
3496 }
3497 } else {
3498 // Page is mapped go down
3499 // to find first not mapped page
3500 imin = imid + 1;
3501 }
3502 }
3503
3504 nbot = nbot + page_sz;
3505
3506 // Adjust stack bottom one page up if last checked page is not mapped
3507 if (mincore_return_value == -1) {
3508 nbot = nbot + page_sz;
3509 }
3510
3511 return nbot;
3512 }
3513
3514 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
3515 int mincore_return_value;
3516 const size_t stripe = 1024; // query this many pages each time
3517 unsigned char vec[stripe + 1];
3518 // set a guard
3519 vec[stripe] = 'X';
3520
3521 const size_t page_sz = os::vm_page_size();
3522 size_t pages = size / page_sz;
3523
3524 assert(is_aligned(start, page_sz), "Start address must be page aligned");
3525 assert(is_aligned(size, page_sz), "Size must be page aligned");
3526
3527 committed_start = NULL;
3528
3529 int loops = (pages + stripe - 1) / stripe;
3530 int committed_pages = 0;
3531 address loop_base = start;
3532 bool found_range = false;
3533
3534 for (int index = 0; index < loops && !found_range; index ++) {
3535 assert(pages > 0, "Nothing to do");
3536 int pages_to_query = (pages >= stripe) ? stripe : pages;
3537 pages -= pages_to_query;
3538
3539 // Get stable read
3540 while ((mincore_return_value = mincore(loop_base, pages_to_query * page_sz, vec)) == -1 && errno == EAGAIN);
3541
3542 // During shutdown, some memory goes away without properly notifying NMT,
3543 // E.g. ConcurrentGCThread/WatcherThread can exit without deleting thread object.
3544 // Bailout and return as not committed for now.
3545 if (mincore_return_value == -1 && errno == ENOMEM) {
3546 return false;
3547 }
3548
3549 assert(vec[stripe] == 'X', "overflow guard");
3550 assert(mincore_return_value == 0, "Range must be valid");
3551 // Process this stripe
3552 for (int vecIdx = 0; vecIdx < pages_to_query; vecIdx ++) {
3553 if ((vec[vecIdx] & 0x01) == 0) { // not committed
3554 // End of current contiguous region
3555 if (committed_start != NULL) {
3556 found_range = true;
3557 break;
3558 }
3559 } else { // committed
3560 // Start of region
3561 if (committed_start == NULL) {
3562 committed_start = loop_base + page_sz * vecIdx;
3563 }
3564 committed_pages ++;
3565 }
3566 }
3567
3568 loop_base += pages_to_query * page_sz;
3569 }
3570
3571 if (committed_start != NULL) {
3572 assert(committed_pages > 0, "Must have committed region");
3573 assert(committed_pages <= int(size / page_sz), "Can not commit more than it has");
3574 assert(committed_start >= start && committed_start < start + size, "Out of range");
3575 committed_size = page_sz * committed_pages;
3576 return true;
3577 } else {
3578 assert(committed_pages == 0, "Should not have committed region");
3579 return false;
3580 }
3581 }
3582
3583
3584 // Linux uses a growable mapping for the stack, and if the mapping for
3585 // the stack guard pages is not removed when we detach a thread the
3586 // stack cannot grow beyond the pages where the stack guard was
3587 // mapped. If at some point later in the process the stack expands to
3588 // that point, the Linux kernel cannot expand the stack any further
3589 // because the guard pages are in the way, and a segfault occurs.
3590 //
3591 // However, it's essential not to split the stack region by unmapping
3592 // a region (leaving a hole) that's already part of the stack mapping,
3593 // so if the stack mapping has already grown beyond the guard pages at
3594 // the time we create them, we have to truncate the stack mapping.
3595 // So, we need to know the extent of the stack mapping when
3596 // create_stack_guard_pages() is called.
3597
3598 // We only need this for stacks that are growable: at the time of
3599 // writing thread stacks don't use growable mappings (i.e. those
3600 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this
3601 // only applies to the main thread.
3602
3603 // If the (growable) stack mapping already extends beyond the point
3604 // where we're going to put our guard pages, truncate the mapping at
3605 // that point by munmap()ping it. This ensures that when we later
3606 // munmap() the guard pages we don't leave a hole in the stack
3607 // mapping. This only affects the main/primordial thread
3608
3609 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
3610 if (os::is_primordial_thread()) {
3611 // As we manually grow stack up to bottom inside create_attached_thread(),
3612 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and
3613 // we don't need to do anything special.
3614 // Check it first, before calling heavy function.
3615 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom();
3616 unsigned char vec[1];
3617
3618 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) {
3619 // Fallback to slow path on all errors, including EAGAIN
3620 stack_extent = (uintptr_t) get_stack_commited_bottom(
3621 os::Linux::initial_thread_stack_bottom(),
3622 (size_t)addr - stack_extent);
3623 }
3624
3625 if (stack_extent < (uintptr_t)addr) {
3626 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent));
3627 }
3628 }
3629
3630 return os::commit_memory(addr, size, !ExecMem);
3631 }
3632
3633 // If this is a growable mapping, remove the guard pages entirely by
3634 // munmap()ping them. If not, just call uncommit_memory(). This only
3635 // affects the main/primordial thread, but guard against future OS changes.
3636 // It's safe to always unmap guard pages for primordial thread because we
3637 // always place it right after end of the mapped region.
3638
3639 bool os::remove_stack_guard_pages(char* addr, size_t size) {
3640 uintptr_t stack_extent, stack_base;
3641
3642 if (os::is_primordial_thread()) {
3643 return ::munmap(addr, size) == 0;
3644 }
3645
3646 return os::uncommit_memory(addr, size);
3647 }
3648
3649 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
3650 // at 'requested_addr'. If there are existing memory mappings at the same
3651 // location, however, they will be overwritten. If 'fixed' is false,
3652 // 'requested_addr' is only treated as a hint, the return value may or
3653 // may not start from the requested address. Unlike Linux mmap(), this
3654 // function returns NULL to indicate failure.
3655 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
3656 char * addr;
3657 int flags;
3658
3659 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
3660 if (fixed) {
3661 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address");
3662 flags |= MAP_FIXED;
3663 }
3664
3665 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
3666 // touch an uncommitted page. Otherwise, the read/write might
3667 // succeed if we have enough swap space to back the physical page.
3668 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
3669 flags, -1, 0);
3670
3671 return addr == MAP_FAILED ? NULL : addr;
3672 }
3673
3674 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address
3675 // (req_addr != NULL) or with a given alignment.
3676 // - bytes shall be a multiple of alignment.
3677 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3678 // - alignment sets the alignment at which memory shall be allocated.
3679 // It must be a multiple of allocation granularity.
3680 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3681 // req_addr or NULL.
3682 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) {
3683
3684 size_t extra_size = bytes;
3685 if (req_addr == NULL && alignment > 0) {
3686 extra_size += alignment;
3687 }
3688
3689 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE,
3690 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
3691 -1, 0);
3692 if (start == MAP_FAILED) {
3693 start = NULL;
3694 } else {
3695 if (req_addr != NULL) {
3696 if (start != req_addr) {
3697 ::munmap(start, extra_size);
3698 start = NULL;
3699 }
3700 } else {
3701 char* const start_aligned = align_up(start, alignment);
3702 char* const end_aligned = start_aligned + bytes;
3703 char* const end = start + extra_size;
3704 if (start_aligned > start) {
3705 ::munmap(start, start_aligned - start);
3706 }
3707 if (end_aligned < end) {
3708 ::munmap(end_aligned, end - end_aligned);
3709 }
3710 start = start_aligned;
3711 }
3712 }
3713 return start;
3714 }
3715
3716 static int anon_munmap(char * addr, size_t size) {
3717 return ::munmap(addr, size) == 0;
3718 }
3719
3720 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
3721 size_t alignment_hint) {
3722 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
3723 }
3724
3725 bool os::pd_release_memory(char* addr, size_t size) {
3726 return anon_munmap(addr, size);
3727 }
3728
3729 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
3730 extern char* g_assert_poison; // assertion poison page address
3731 #endif
3732
3733 static bool linux_mprotect(char* addr, size_t size, int prot) {
3734 // Linux wants the mprotect address argument to be page aligned.
3735 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size());
3736
3737 // According to SUSv3, mprotect() should only be used with mappings
3738 // established by mmap(), and mmap() always maps whole pages. Unaligned
3739 // 'addr' likely indicates problem in the VM (e.g. trying to change
3740 // protection of malloc'ed or statically allocated memory). Check the
3741 // caller if you hit this assert.
3742 assert(addr == bottom, "sanity check");
3743
3744 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size());
3745 // Don't log anything if we're executing in the poison page signal handling
3746 // context. It can lead to reentrant use of other parts of the VM code.
3747 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
3748 if (addr != g_assert_poison)
3749 #endif
3750 Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(bottom), p2i(bottom+size), prot);
3751 return ::mprotect(bottom, size, prot) == 0;
3752 }
3753
3754 // Set protections specified
3755 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
3756 bool is_committed) {
3757 unsigned int p = 0;
3758 switch (prot) {
3759 case MEM_PROT_NONE: p = PROT_NONE; break;
3760 case MEM_PROT_READ: p = PROT_READ; break;
3761 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
3762 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
3763 default:
3764 ShouldNotReachHere();
3765 }
3766 // is_committed is unused.
3767 return linux_mprotect(addr, bytes, p);
3768 }
3769
3770 bool os::guard_memory(char* addr, size_t size) {
3771 return linux_mprotect(addr, size, PROT_NONE);
3772 }
3773
3774 bool os::unguard_memory(char* addr, size_t size) {
3775 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE);
3776 }
3777
3778 bool os::Linux::transparent_huge_pages_sanity_check(bool warn,
3779 size_t page_size) {
3780 bool result = false;
3781 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,
3782 MAP_ANONYMOUS|MAP_PRIVATE,
3783 -1, 0);
3784 if (p != MAP_FAILED) {
3785 void *aligned_p = align_up(p, page_size);
3786
3787 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0;
3788
3789 munmap(p, page_size * 2);
3790 }
3791
3792 if (warn && !result) {
3793 warning("TransparentHugePages is not supported by the operating system.");
3794 }
3795
3796 return result;
3797 }
3798
3799 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) {
3800 bool result = false;
3801 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
3802 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB,
3803 -1, 0);
3804
3805 if (p != MAP_FAILED) {
3806 // We don't know if this really is a huge page or not.
3807 FILE *fp = fopen("/proc/self/maps", "r");
3808 if (fp) {
3809 while (!feof(fp)) {
3810 char chars[257];
3811 long x = 0;
3812 if (fgets(chars, sizeof(chars), fp)) {
3813 if (sscanf(chars, "%lx-%*x", &x) == 1
3814 && x == (long)p) {
3815 if (strstr (chars, "hugepage")) {
3816 result = true;
3817 break;
3818 }
3819 }
3820 }
3821 }
3822 fclose(fp);
3823 }
3824 munmap(p, page_size);
3825 }
3826
3827 if (warn && !result) {
3828 warning("HugeTLBFS is not supported by the operating system.");
3829 }
3830
3831 return result;
3832 }
3833
3834 // From the coredump_filter documentation:
3835 //
3836 // - (bit 0) anonymous private memory
3837 // - (bit 1) anonymous shared memory
3838 // - (bit 2) file-backed private memory
3839 // - (bit 3) file-backed shared memory
3840 // - (bit 4) ELF header pages in file-backed private memory areas (it is
3841 // effective only if the bit 2 is cleared)
3842 // - (bit 5) hugetlb private memory
3843 // - (bit 6) hugetlb shared memory
3844 // - (bit 7) dax private memory
3845 // - (bit 8) dax shared memory
3846 //
3847 static void set_coredump_filter(CoredumpFilterBit bit) {
3848 FILE *f;
3849 long cdm;
3850
3851 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
3852 return;
3853 }
3854
3855 if (fscanf(f, "%lx", &cdm) != 1) {
3856 fclose(f);
3857 return;
3858 }
3859
3860 long saved_cdm = cdm;
3861 rewind(f);
3862 cdm |= bit;
3863
3864 if (cdm != saved_cdm) {
3865 fprintf(f, "%#lx", cdm);
3866 }
3867
3868 fclose(f);
3869 }
3870
3871 // Large page support
3872
3873 static size_t _large_page_size = 0;
3874
3875 size_t os::Linux::find_default_large_page_size() {
3876 if (_default_large_page_size != 0) {
3877 return _default_large_page_size;
3878 }
3879 size_t large_page_size = 0;
3880
3881 // large_page_size on Linux is used to round up heap size. x86 uses either
3882 // 2M or 4M page, depending on whether PAE (Physical Address Extensions)
3883 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use
3884 // page as large as 256M.
3885 //
3886 // Here we try to figure out page size by parsing /proc/meminfo and looking
3887 // for a line with the following format:
3888 // Hugepagesize: 2048 kB
3889 //
3890 // If we can't determine the value (e.g. /proc is not mounted, or the text
3891 // format has been changed), we'll use the largest page size supported by
3892 // the processor.
3893
3894 #ifndef ZERO
3895 large_page_size =
3896 AARCH64_ONLY(2 * M)
3897 AMD64_ONLY(2 * M)
3898 ARM32_ONLY(2 * M)
3899 IA32_ONLY(4 * M)
3900 IA64_ONLY(256 * M)
3901 PPC_ONLY(4 * M)
3902 S390_ONLY(1 * M);
3903 #endif // ZERO
3904
3905 FILE *fp = fopen("/proc/meminfo", "r");
3906 if (fp) {
3907 while (!feof(fp)) {
3908 int x = 0;
3909 char buf[16];
3910 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) {
3911 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) {
3912 large_page_size = x * K;
3913 break;
3914 }
3915 } else {
3916 // skip to next line
3917 for (;;) {
3918 int ch = fgetc(fp);
3919 if (ch == EOF || ch == (int)'\n') break;
3920 }
3921 }
3922 }
3923 fclose(fp);
3924 }
3925 return large_page_size;
3926 }
3927
3928 size_t os::Linux::find_large_page_size(size_t large_page_size) {
3929 if (_default_large_page_size == 0) {
3930 _default_large_page_size = Linux::find_default_large_page_size();
3931 }
3932 // We need to scan /sys/kernel/mm/hugepages
3933 // to discover the available page sizes
3934 const char* sys_hugepages = "/sys/kernel/mm/hugepages";
3935
3936 DIR *dir = opendir(sys_hugepages);
3937 if (dir == NULL) {
3938 return _default_large_page_size;
3939 }
3940
3941 struct dirent *entry;
3942 size_t page_size;
3943 while ((entry = readdir(dir)) != NULL) {
3944 if (entry->d_type == DT_DIR &&
3945 sscanf(entry->d_name, "hugepages-%zukB", &page_size) == 1) {
3946 // The kernel is using kB, hotspot uses bytes
3947 if (large_page_size == page_size * K) {
3948 closedir(dir);
3949 return large_page_size;
3950 }
3951 }
3952 }
3953 closedir(dir);
3954 return _default_large_page_size;
3955 }
3956
3957 size_t os::Linux::setup_large_page_size() {
3958 _default_large_page_size = Linux::find_default_large_page_size();
3959
3960 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != _default_large_page_size ) {
3961 _large_page_size = find_large_page_size(LargePageSizeInBytes);
3962 if (_large_page_size == _default_large_page_size) {
3963 warning("Setting LargePageSizeInBytes=" SIZE_FORMAT " has no effect on this OS. Using the default large page size "
3964 SIZE_FORMAT "%s.",
3965 LargePageSizeInBytes,
3966 byte_size_in_proper_unit(_large_page_size), proper_unit_for_byte_size(_large_page_size));
3967 }
3968 } else {
3969 _large_page_size = _default_large_page_size;
3970 }
3971
3972 const size_t default_page_size = (size_t)Linux::page_size();
3973 if (_large_page_size > default_page_size) {
3974 _page_sizes[0] = _large_page_size;
3975 _page_sizes[1] = default_page_size;
3976 _page_sizes[2] = 0;
3977 }
3978
3979 return _large_page_size;
3980 }
3981
3982 size_t os::Linux::default_large_page_size() {
3983 return _default_large_page_size;
3984 }
3985
3986 bool os::Linux::setup_large_page_type(size_t page_size) {
3987 if (FLAG_IS_DEFAULT(UseHugeTLBFS) &&
3988 FLAG_IS_DEFAULT(UseSHM) &&
3989 FLAG_IS_DEFAULT(UseTransparentHugePages)) {
3990
3991 // The type of large pages has not been specified by the user.
3992
3993 // Try UseHugeTLBFS and then UseSHM.
3994 UseHugeTLBFS = UseSHM = true;
3995
3996 // Don't try UseTransparentHugePages since there are known
3997 // performance issues with it turned on. This might change in the future.
3998 UseTransparentHugePages = false;
3999 }
4000
4001 if (UseTransparentHugePages) {
4002 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages);
4003 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) {
4004 UseHugeTLBFS = false;
4005 UseSHM = false;
4006 return true;
4007 }
4008 UseTransparentHugePages = false;
4009 }
4010
4011 if (UseHugeTLBFS) {
4012 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS);
4013 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) {
4014 UseSHM = false;
4015 return true;
4016 }
4017 UseHugeTLBFS = false;
4018 }
4019
4020 return UseSHM;
4021 }
4022
4023 void os::large_page_init() {
4024 if (!UseLargePages &&
4025 !UseTransparentHugePages &&
4026 !UseHugeTLBFS &&
4027 !UseSHM) {
4028 // Not using large pages.
4029 return;
4030 }
4031
4032 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) {
4033 // The user explicitly turned off large pages.
4034 // Ignore the rest of the large pages flags.
4035 UseTransparentHugePages = false;
4036 UseHugeTLBFS = false;
4037 UseSHM = false;
4038 return;
4039 }
4040
4041 size_t large_page_size = Linux::setup_large_page_size();
4042 UseLargePages = Linux::setup_large_page_type(large_page_size);
4043
4044 set_coredump_filter(LARGEPAGES_BIT);
4045 }
4046
4047 #ifndef SHM_HUGETLB
4048 #define SHM_HUGETLB 04000
4049 #endif
4050
4051 #define shm_warning_format(format, ...) \
4052 do { \
4053 if (UseLargePages && \
4054 (!FLAG_IS_DEFAULT(UseLargePages) || \
4055 !FLAG_IS_DEFAULT(UseSHM) || \
4056 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \
4057 warning(format, __VA_ARGS__); \
4058 } \
4059 } while (0)
4060
4061 #define shm_warning(str) shm_warning_format("%s", str)
4062
4063 #define shm_warning_with_errno(str) \
4064 do { \
4065 int err = errno; \
4066 shm_warning_format(str " (error = %d)", err); \
4067 } while (0)
4068
4069 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) {
4070 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment");
4071
4072 if (!is_aligned(alignment, SHMLBA)) {
4073 assert(false, "Code below assumes that alignment is at least SHMLBA aligned");
4074 return NULL;
4075 }
4076
4077 // To ensure that we get 'alignment' aligned memory from shmat,
4078 // we pre-reserve aligned virtual memory and then attach to that.
4079
4080 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL);
4081 if (pre_reserved_addr == NULL) {
4082 // Couldn't pre-reserve aligned memory.
4083 shm_warning("Failed to pre-reserve aligned memory for shmat.");
4084 return NULL;
4085 }
4086
4087 // SHM_REMAP is needed to allow shmat to map over an existing mapping.
4088 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP);
4089
4090 if ((intptr_t)addr == -1) {
4091 int err = errno;
4092 shm_warning_with_errno("Failed to attach shared memory.");
4093
4094 assert(err != EACCES, "Unexpected error");
4095 assert(err != EIDRM, "Unexpected error");
4096 assert(err != EINVAL, "Unexpected error");
4097
4098 // Since we don't know if the kernel unmapped the pre-reserved memory area
4099 // we can't unmap it, since that would potentially unmap memory that was
4100 // mapped from other threads.
4101 return NULL;
4102 }
4103
4104 return addr;
4105 }
4106
4107 static char* shmat_at_address(int shmid, char* req_addr) {
4108 if (!is_aligned(req_addr, SHMLBA)) {
4109 assert(false, "Requested address needs to be SHMLBA aligned");
4110 return NULL;
4111 }
4112
4113 char* addr = (char*)shmat(shmid, req_addr, 0);
4114
4115 if ((intptr_t)addr == -1) {
4116 shm_warning_with_errno("Failed to attach shared memory.");
4117 return NULL;
4118 }
4119
4120 return addr;
4121 }
4122
4123 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) {
4124 // If a req_addr has been provided, we assume that the caller has already aligned the address.
4125 if (req_addr != NULL) {
4126 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size");
4127 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment");
4128 return shmat_at_address(shmid, req_addr);
4129 }
4130
4131 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically
4132 // return large page size aligned memory addresses when req_addr == NULL.
4133 // However, if the alignment is larger than the large page size, we have
4134 // to manually ensure that the memory returned is 'alignment' aligned.
4135 if (alignment > os::large_page_size()) {
4136 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size");
4137 return shmat_with_alignment(shmid, bytes, alignment);
4138 } else {
4139 return shmat_at_address(shmid, NULL);
4140 }
4141 }
4142
4143 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment,
4144 char* req_addr, bool exec) {
4145 // "exec" is passed in but not used. Creating the shared image for
4146 // the code cache doesn't have an SHM_X executable permission to check.
4147 assert(UseLargePages && UseSHM, "only for SHM large pages");
4148 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
4149 assert(is_aligned(req_addr, alignment), "Unaligned address");
4150
4151 if (!is_aligned(bytes, os::large_page_size())) {
4152 return NULL; // Fallback to small pages.
4153 }
4154
4155 // Create a large shared memory region to attach to based on size.
4156 // Currently, size is the total size of the heap.
4157 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);
4158 if (shmid == -1) {
4159 // Possible reasons for shmget failure:
4160 // 1. shmmax is too small for Java heap.
4161 // > check shmmax value: cat /proc/sys/kernel/shmmax
4162 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
4163 // 2. not enough large page memory.
4164 // > check available large pages: cat /proc/meminfo
4165 // > increase amount of large pages:
4166 // echo new_value > /proc/sys/vm/nr_hugepages
4167 // Note 1: different Linux may use different name for this property,
4168 // e.g. on Redhat AS-3 it is "hugetlb_pool".
4169 // Note 2: it's possible there's enough physical memory available but
4170 // they are so fragmented after a long run that they can't
4171 // coalesce into large pages. Try to reserve large pages when
4172 // the system is still "fresh".
4173 shm_warning_with_errno("Failed to reserve shared memory.");
4174 return NULL;
4175 }
4176
4177 // Attach to the region.
4178 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr);
4179
4180 // Remove shmid. If shmat() is successful, the actual shared memory segment
4181 // will be deleted when it's detached by shmdt() or when the process
4182 // terminates. If shmat() is not successful this will remove the shared
4183 // segment immediately.
4184 shmctl(shmid, IPC_RMID, NULL);
4185
4186 return addr;
4187 }
4188
4189 static void warn_on_large_pages_failure(char* req_addr, size_t bytes,
4190 int error) {
4191 assert(error == ENOMEM, "Only expect to fail if no memory is available");
4192
4193 bool warn_on_failure = UseLargePages &&
4194 (!FLAG_IS_DEFAULT(UseLargePages) ||
4195 !FLAG_IS_DEFAULT(UseHugeTLBFS) ||
4196 !FLAG_IS_DEFAULT(LargePageSizeInBytes));
4197
4198 if (warn_on_failure) {
4199 char msg[128];
4200 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: "
4201 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error);
4202 warning("%s", msg);
4203 }
4204 }
4205
4206 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes,
4207 char* req_addr,
4208 bool exec) {
4209 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
4210 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size");
4211 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
4212
4213 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
4214 int flags = MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB;
4215
4216 if (os::large_page_size() != default_large_page_size()) {
4217 flags |= (exact_log2(os::large_page_size()) << MAP_HUGE_SHIFT);
4218 }
4219 char* addr = (char*)::mmap(req_addr, bytes, prot, flags, -1, 0);
4220
4221 if (addr == MAP_FAILED) {
4222 warn_on_large_pages_failure(req_addr, bytes, errno);
4223 return NULL;
4224 }
4225
4226 assert(is_aligned(addr, os::large_page_size()), "Must be");
4227
4228 return addr;
4229 }
4230
4231 // Reserve memory using mmap(MAP_HUGETLB).
4232 // - bytes shall be a multiple of alignment.
4233 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
4234 // - alignment sets the alignment at which memory shall be allocated.
4235 // It must be a multiple of allocation granularity.
4236 // Returns address of memory or NULL. If req_addr was not NULL, will only return
4237 // req_addr or NULL.
4238 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes,
4239 size_t alignment,
4240 char* req_addr,
4241 bool exec) {
4242 size_t large_page_size = os::large_page_size();
4243 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes");
4244
4245 assert(is_aligned(req_addr, alignment), "Must be");
4246 assert(is_aligned(bytes, alignment), "Must be");
4247
4248 // First reserve - but not commit - the address range in small pages.
4249 char* const start = anon_mmap_aligned(bytes, alignment, req_addr);
4250
4251 if (start == NULL) {
4252 return NULL;
4253 }
4254
4255 assert(is_aligned(start, alignment), "Must be");
4256
4257 char* end = start + bytes;
4258
4259 // Find the regions of the allocated chunk that can be promoted to large pages.
4260 char* lp_start = align_up(start, large_page_size);
4261 char* lp_end = align_down(end, large_page_size);
4262
4263 size_t lp_bytes = lp_end - lp_start;
4264
4265 assert(is_aligned(lp_bytes, large_page_size), "Must be");
4266
4267 if (lp_bytes == 0) {
4268 // The mapped region doesn't even span the start and the end of a large page.
4269 // Fall back to allocate a non-special area.
4270 ::munmap(start, end - start);
4271 return NULL;
4272 }
4273
4274 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
4275 int flags = MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED;
4276 void* result;
4277
4278 // Commit small-paged leading area.
4279 if (start != lp_start) {
4280 result = ::mmap(start, lp_start - start, prot, flags, -1, 0);
4281 if (result == MAP_FAILED) {
4282 ::munmap(lp_start, end - lp_start);
4283 return NULL;
4284 }
4285 }
4286
4287 // Commit large-paged area.
4288 flags |= MAP_HUGETLB;
4289
4290 if (os::large_page_size() != default_large_page_size()) {
4291 flags |= (exact_log2(os::large_page_size()) << MAP_HUGE_SHIFT);
4292 }
4293
4294 result = ::mmap(lp_start, lp_bytes, prot, flags, -1, 0);
4295 if (result == MAP_FAILED) {
4296 warn_on_large_pages_failure(lp_start, lp_bytes, errno);
4297 // If the mmap above fails, the large pages region will be unmapped and we
4298 // have regions before and after with small pages. Release these regions.
4299 //
4300 // | mapped | unmapped | mapped |
4301 // ^ ^ ^ ^
4302 // start lp_start lp_end end
4303 //
4304 ::munmap(start, lp_start - start);
4305 ::munmap(lp_end, end - lp_end);
4306 return NULL;
4307 }
4308
4309 // Commit small-paged trailing area.
4310 if (lp_end != end) {
4311 result = ::mmap(lp_end, end - lp_end, prot,
4312 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
4313 -1, 0);
4314 if (result == MAP_FAILED) {
4315 ::munmap(start, lp_end - start);
4316 return NULL;
4317 }
4318 }
4319
4320 return start;
4321 }
4322
4323 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes,
4324 size_t alignment,
4325 char* req_addr,
4326 bool exec) {
4327 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
4328 assert(is_aligned(req_addr, alignment), "Must be");
4329 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be");
4330 assert(is_power_of_2(os::large_page_size()), "Must be");
4331 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes");
4332
4333 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) {
4334 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec);
4335 } else {
4336 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec);
4337 }
4338 }
4339
4340 char* os::pd_reserve_memory_special(size_t bytes, size_t alignment,
4341 char* req_addr, bool exec) {
4342 assert(UseLargePages, "only for large pages");
4343
4344 char* addr;
4345 if (UseSHM) {
4346 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec);
4347 } else {
4348 assert(UseHugeTLBFS, "must be");
4349 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec);
4350 }
4351
4352 if (addr != NULL) {
4353 if (UseNUMAInterleaving) {
4354 numa_make_global(addr, bytes);
4355 }
4356 }
4357
4358 return addr;
4359 }
4360
4361 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) {
4362 // detaching the SHM segment will also delete it, see reserve_memory_special_shm()
4363 return shmdt(base) == 0;
4364 }
4365
4366 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) {
4367 return pd_release_memory(base, bytes);
4368 }
4369
4370 bool os::pd_release_memory_special(char* base, size_t bytes) {
4371 assert(UseLargePages, "only for large pages");
4372 bool res;
4373
4374 if (UseSHM) {
4375 res = os::Linux::release_memory_special_shm(base, bytes);
4376 } else {
4377 assert(UseHugeTLBFS, "must be");
4378 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes);
4379 }
4380 return res;
4381 }
4382
4383 size_t os::large_page_size() {
4384 return _large_page_size;
4385 }
4386
4387 // With SysV SHM the entire memory region must be allocated as shared
4388 // memory.
4389 // HugeTLBFS allows application to commit large page memory on demand.
4390 // However, when committing memory with HugeTLBFS fails, the region
4391 // that was supposed to be committed will lose the old reservation
4392 // and allow other threads to steal that memory region. Because of this
4393 // behavior we can't commit HugeTLBFS memory.
4394 bool os::can_commit_large_page_memory() {
4395 return UseTransparentHugePages;
4396 }
4397
4398 bool os::can_execute_large_page_memory() {
4399 return UseTransparentHugePages || UseHugeTLBFS;
4400 }
4401
4402 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
4403 assert(file_desc >= 0, "file_desc is not valid");
4404 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
4405 if (result != NULL) {
4406 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
4407 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
4408 }
4409 }
4410 return result;
4411 }
4412
4413 // Reserve memory at an arbitrary address, only if that area is
4414 // available (and not reserved for something else).
4415
4416 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
4417 // Assert only that the size is a multiple of the page size, since
4418 // that's all that mmap requires, and since that's all we really know
4419 // about at this low abstraction level. If we need higher alignment,
4420 // we can either pass an alignment to this method or verify alignment
4421 // in one of the methods further up the call chain. See bug 5044738.
4422 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
4423
4424 // Repeatedly allocate blocks until the block is allocated at the
4425 // right spot.
4426
4427 // Linux mmap allows caller to pass an address as hint; give it a try first,
4428 // if kernel honors the hint then we can return immediately.
4429 char * addr = anon_mmap(requested_addr, bytes, false);
4430 if (addr == requested_addr) {
4431 return requested_addr;
4432 }
4433
4434 if (addr != NULL) {
4435 // mmap() is successful but it fails to reserve at the requested address
4436 anon_munmap(addr, bytes);
4437 }
4438
4439 return NULL;
4440 }
4441
4442 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
4443 void os::infinite_sleep() {
4444 while (true) { // sleep forever ...
4445 ::sleep(100); // ... 100 seconds at a time
4446 }
4447 }
4448
4449 // Used to convert frequent JVM_Yield() to nops
4450 bool os::dont_yield() {
4451 return DontYieldALot;
4452 }
4453
4454 // Linux CFS scheduler (since 2.6.23) does not guarantee sched_yield(2) will
4455 // actually give up the CPU. Since skip buddy (v2.6.28):
4456 //
4457 // * Sets the yielding task as skip buddy for current CPU's run queue.
4458 // * Picks next from run queue, if empty, picks a skip buddy (can be the yielding task).
4459 // * Clears skip buddies for this run queue (yielding task no longer a skip buddy).
4460 //
4461 // An alternative is calling os::naked_short_nanosleep with a small number to avoid
4462 // getting re-scheduled immediately.
4463 //
4464 void os::naked_yield() {
4465 sched_yield();
4466 }
4467
4468 ////////////////////////////////////////////////////////////////////////////////
4469 // thread priority support
4470
4471 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER
4472 // only supports dynamic priority, static priority must be zero. For real-time
4473 // applications, Linux supports SCHED_RR which allows static priority (1-99).
4474 // However, for large multi-threaded applications, SCHED_RR is not only slower
4475 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
4476 // of 5 runs - Sep 2005).
4477 //
4478 // The following code actually changes the niceness of kernel-thread/LWP. It
4479 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
4480 // not the entire user process, and user level threads are 1:1 mapped to kernel
4481 // threads. It has always been the case, but could change in the future. For
4482 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
4483 // It is only used when ThreadPriorityPolicy=1 and may require system level permission
4484 // (e.g., root privilege or CAP_SYS_NICE capability).
4485
4486 int os::java_to_os_priority[CriticalPriority + 1] = {
4487 19, // 0 Entry should never be used
4488
4489 4, // 1 MinPriority
4490 3, // 2
4491 2, // 3
4492
4493 1, // 4
4494 0, // 5 NormPriority
4495 -1, // 6
4496
4497 -2, // 7
4498 -3, // 8
4499 -4, // 9 NearMaxPriority
4500
4501 -5, // 10 MaxPriority
4502
4503 -5 // 11 CriticalPriority
4504 };
4505
4506 static int prio_init() {
4507 if (ThreadPriorityPolicy == 1) {
4508 if (geteuid() != 0) {
4509 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy) && !FLAG_IS_JIMAGE_RESOURCE(ThreadPriorityPolicy)) {
4510 warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
4511 "e.g., being the root user. If the necessary permission is not " \
4512 "possessed, changes to priority will be silently ignored.");
4513 }
4514 }
4515 }
4516 if (UseCriticalJavaThreadPriority) {
4517 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
4518 }
4519 return 0;
4520 }
4521
4522 OSReturn os::set_native_priority(Thread* thread, int newpri) {
4523 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
4524
4525 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
4526 return (ret == 0) ? OS_OK : OS_ERR;
4527 }
4528
4529 OSReturn os::get_native_priority(const Thread* const thread,
4530 int *priority_ptr) {
4531 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
4532 *priority_ptr = java_to_os_priority[NormPriority];
4533 return OS_OK;
4534 }
4535
4536 errno = 0;
4537 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
4538 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
4539 }
4540
4541 ////////////////////////////////////////////////////////////////////////////////
4542 // suspend/resume support
4543
4544 // The low-level signal-based suspend/resume support is a remnant from the
4545 // old VM-suspension that used to be for java-suspension, safepoints etc,
4546 // within hotspot. Currently used by JFR's OSThreadSampler
4547 //
4548 // The remaining code is greatly simplified from the more general suspension
4549 // code that used to be used.
4550 //
4551 // The protocol is quite simple:
4552 // - suspend:
4553 // - sends a signal to the target thread
4554 // - polls the suspend state of the osthread using a yield loop
4555 // - target thread signal handler (SR_handler) sets suspend state
4556 // and blocks in sigsuspend until continued
4557 // - resume:
4558 // - sets target osthread state to continue
4559 // - sends signal to end the sigsuspend loop in the SR_handler
4560 //
4561 // Note that the SR_lock plays no role in this suspend/resume protocol,
4562 // but is checked for NULL in SR_handler as a thread termination indicator.
4563 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
4564 //
4565 // Note that resume_clear_context() and suspend_save_context() are needed
4566 // by SR_handler(), so that fetch_frame_from_context() works,
4567 // which in part is used by:
4568 // - Forte Analyzer: AsyncGetCallTrace()
4569 // - StackBanging: get_frame_at_stack_banging_point()
4570
4571 static void resume_clear_context(OSThread *osthread) {
4572 osthread->set_ucontext(NULL);
4573 osthread->set_siginfo(NULL);
4574 }
4575
4576 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo,
4577 ucontext_t* context) {
4578 osthread->set_ucontext(context);
4579 osthread->set_siginfo(siginfo);
4580 }
4581
4582 // Handler function invoked when a thread's execution is suspended or
4583 // resumed. We have to be careful that only async-safe functions are
4584 // called here (Note: most pthread functions are not async safe and
4585 // should be avoided.)
4586 //
4587 // Note: sigwait() is a more natural fit than sigsuspend() from an
4588 // interface point of view, but sigwait() prevents the signal hander
4589 // from being run. libpthread would get very confused by not having
4590 // its signal handlers run and prevents sigwait()'s use with the
4591 // mutex granting granting signal.
4592 //
4593 // Currently only ever called on the VMThread and JavaThreads (PC sampling)
4594 //
4595 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
4596 // Save and restore errno to avoid confusing native code with EINTR
4597 // after sigsuspend.
4598 int old_errno = errno;
4599
4600 Thread* thread = Thread::current_or_null_safe();
4601 assert(thread != NULL, "Missing current thread in SR_handler");
4602
4603 // On some systems we have seen signal delivery get "stuck" until the signal
4604 // mask is changed as part of thread termination. Check that the current thread
4605 // has not already terminated (via SR_lock()) - else the following assertion
4606 // will fail because the thread is no longer a JavaThread as the ~JavaThread
4607 // destructor has completed.
4608
4609 if (thread->SR_lock() == NULL) {
4610 return;
4611 }
4612
4613 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
4614
4615 OSThread* osthread = thread->osthread();
4616
4617 os::SuspendResume::State current = osthread->sr.state();
4618 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
4619 suspend_save_context(osthread, siginfo, context);
4620
4621 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
4622 os::SuspendResume::State state = osthread->sr.suspended();
4623 if (state == os::SuspendResume::SR_SUSPENDED) {
4624 sigset_t suspend_set; // signals for sigsuspend()
4625 sigemptyset(&suspend_set);
4626 // get current set of blocked signals and unblock resume signal
4627 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
4628 sigdelset(&suspend_set, SR_signum);
4629
4630 sr_semaphore.signal();
4631 // wait here until we are resumed
4632 while (1) {
4633 sigsuspend(&suspend_set);
4634
4635 os::SuspendResume::State result = osthread->sr.running();
4636 if (result == os::SuspendResume::SR_RUNNING) {
4637 sr_semaphore.signal();
4638 break;
4639 }
4640 }
4641
4642 } else if (state == os::SuspendResume::SR_RUNNING) {
4643 // request was cancelled, continue
4644 } else {
4645 ShouldNotReachHere();
4646 }
4647
4648 resume_clear_context(osthread);
4649 } else if (current == os::SuspendResume::SR_RUNNING) {
4650 // request was cancelled, continue
4651 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
4652 // ignore
4653 } else {
4654 // ignore
4655 }
4656
4657 errno = old_errno;
4658 }
4659
4660 static int SR_initialize() {
4661 struct sigaction act;
4662 char *s;
4663
4664 // Get signal number to use for suspend/resume
4665 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
4666 int sig = ::strtol(s, 0, 10);
4667 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769.
4668 sig < NSIG) { // Must be legal signal and fit into sigflags[].
4669 SR_signum = sig;
4670 } else {
4671 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
4672 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
4673 }
4674 }
4675
4676 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
4677 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
4678
4679 sigemptyset(&SR_sigset);
4680 sigaddset(&SR_sigset, SR_signum);
4681
4682 // Set up signal handler for suspend/resume
4683 act.sa_flags = SA_RESTART|SA_SIGINFO;
4684 act.sa_handler = (void (*)(int)) SR_handler;
4685
4686 // SR_signum is blocked by default.
4687 // 4528190 - We also need to block pthread restart signal (32 on all
4688 // supported Linux platforms). Note that LinuxThreads need to block
4689 // this signal for all threads to work properly. So we don't have
4690 // to use hard-coded signal number when setting up the mask.
4691 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
4692
4693 if (sigaction(SR_signum, &act, 0) == -1) {
4694 return -1;
4695 }
4696
4697 // Save signal flag
4698 os::Linux::set_our_sigflags(SR_signum, act.sa_flags);
4699 return 0;
4700 }
4701
4702 static int sr_notify(OSThread* osthread) {
4703 int status = pthread_kill(osthread->pthread_id(), SR_signum);
4704 assert_status(status == 0, status, "pthread_kill");
4705 return status;
4706 }
4707
4708 // "Randomly" selected value for how long we want to spin
4709 // before bailing out on suspending a thread, also how often
4710 // we send a signal to a thread we want to resume
4711 static const int RANDOMLY_LARGE_INTEGER = 1000000;
4712 static const int RANDOMLY_LARGE_INTEGER2 = 100;
4713
4714 // returns true on success and false on error - really an error is fatal
4715 // but this seems the normal response to library errors
4716 static bool do_suspend(OSThread* osthread) {
4717 assert(osthread->sr.is_running(), "thread should be running");
4718 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
4719
4720 // mark as suspended and send signal
4721 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
4722 // failed to switch, state wasn't running?
4723 ShouldNotReachHere();
4724 return false;
4725 }
4726
4727 if (sr_notify(osthread) != 0) {
4728 ShouldNotReachHere();
4729 }
4730
4731 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
4732 while (true) {
4733 if (sr_semaphore.timedwait(2)) {
4734 break;
4735 } else {
4736 // timeout
4737 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
4738 if (cancelled == os::SuspendResume::SR_RUNNING) {
4739 return false;
4740 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
4741 // make sure that we consume the signal on the semaphore as well
4742 sr_semaphore.wait();
4743 break;
4744 } else {
4745 ShouldNotReachHere();
4746 return false;
4747 }
4748 }
4749 }
4750
4751 guarantee(osthread->sr.is_suspended(), "Must be suspended");
4752 return true;
4753 }
4754
4755 static void do_resume(OSThread* osthread) {
4756 assert(osthread->sr.is_suspended(), "thread should be suspended");
4757 assert(!sr_semaphore.trywait(), "invalid semaphore state");
4758
4759 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
4760 // failed to switch to WAKEUP_REQUEST
4761 ShouldNotReachHere();
4762 return;
4763 }
4764
4765 while (true) {
4766 if (sr_notify(osthread) == 0) {
4767 if (sr_semaphore.timedwait(2)) {
4768 if (osthread->sr.is_running()) {
4769 return;
4770 }
4771 }
4772 } else {
4773 ShouldNotReachHere();
4774 }
4775 }
4776
4777 guarantee(osthread->sr.is_running(), "Must be running!");
4778 }
4779
4780 ///////////////////////////////////////////////////////////////////////////////////
4781 // signal handling (except suspend/resume)
4782
4783 // This routine may be used by user applications as a "hook" to catch signals.
4784 // The user-defined signal handler must pass unrecognized signals to this
4785 // routine, and if it returns true (non-zero), then the signal handler must
4786 // return immediately. If the flag "abort_if_unrecognized" is true, then this
4787 // routine will never retun false (zero), but instead will execute a VM panic
4788 // routine kill the process.
4789 //
4790 // If this routine returns false, it is OK to call it again. This allows
4791 // the user-defined signal handler to perform checks either before or after
4792 // the VM performs its own checks. Naturally, the user code would be making
4793 // a serious error if it tried to handle an exception (such as a null check
4794 // or breakpoint) that the VM was generating for its own correct operation.
4795 //
4796 // This routine may recognize any of the following kinds of signals:
4797 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
4798 // It should be consulted by handlers for any of those signals.
4799 //
4800 // The caller of this routine must pass in the three arguments supplied
4801 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
4802 // field of the structure passed to sigaction(). This routine assumes that
4803 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
4804 //
4805 // Note that the VM will print warnings if it detects conflicting signal
4806 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
4807 //
4808 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo,
4809 siginfo_t* siginfo,
4810 void* ucontext,
4811 int abort_if_unrecognized);
4812
4813 static void signalHandler(int sig, siginfo_t* info, void* uc) {
4814 assert(info != NULL && uc != NULL, "it must be old kernel");
4815 int orig_errno = errno; // Preserve errno value over signal handler.
4816 JVM_handle_linux_signal(sig, info, uc, true);
4817 errno = orig_errno;
4818 }
4819
4820
4821 // This boolean allows users to forward their own non-matching signals
4822 // to JVM_handle_linux_signal, harmlessly.
4823 bool os::Linux::signal_handlers_are_installed = false;
4824
4825 // For signal-chaining
4826 bool os::Linux::libjsig_is_loaded = false;
4827 typedef struct sigaction *(*get_signal_t)(int);
4828 get_signal_t os::Linux::get_signal_action = NULL;
4829
4830 struct sigaction* os::Linux::get_chained_signal_action(int sig) {
4831 struct sigaction *actp = NULL;
4832
4833 if (libjsig_is_loaded) {
4834 // Retrieve the old signal handler from libjsig
4835 actp = (*get_signal_action)(sig);
4836 }
4837 if (actp == NULL) {
4838 // Retrieve the preinstalled signal handler from jvm
4839 actp = os::Posix::get_preinstalled_handler(sig);
4840 }
4841
4842 return actp;
4843 }
4844
4845 static bool call_chained_handler(struct sigaction *actp, int sig,
4846 siginfo_t *siginfo, void *context) {
4847 // Call the old signal handler
4848 if (actp->sa_handler == SIG_DFL) {
4849 // It's more reasonable to let jvm treat it as an unexpected exception
4850 // instead of taking the default action.
4851 return false;
4852 } else if (actp->sa_handler != SIG_IGN) {
4853 if ((actp->sa_flags & SA_NODEFER) == 0) {
4854 // automaticlly block the signal
4855 sigaddset(&(actp->sa_mask), sig);
4856 }
4857
4858 sa_handler_t hand = NULL;
4859 sa_sigaction_t sa = NULL;
4860 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
4861 // retrieve the chained handler
4862 if (siginfo_flag_set) {
4863 sa = actp->sa_sigaction;
4864 } else {
4865 hand = actp->sa_handler;
4866 }
4867
4868 if ((actp->sa_flags & SA_RESETHAND) != 0) {
4869 actp->sa_handler = SIG_DFL;
4870 }
4871
4872 // try to honor the signal mask
4873 sigset_t oset;
4874 sigemptyset(&oset);
4875 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
4876
4877 // call into the chained handler
4878 if (siginfo_flag_set) {
4879 (*sa)(sig, siginfo, context);
4880 } else {
4881 (*hand)(sig);
4882 }
4883
4884 // restore the signal mask
4885 pthread_sigmask(SIG_SETMASK, &oset, NULL);
4886 }
4887 // Tell jvm's signal handler the signal is taken care of.
4888 return true;
4889 }
4890
4891 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) {
4892 bool chained = false;
4893 // signal-chaining
4894 if (UseSignalChaining) {
4895 struct sigaction *actp = get_chained_signal_action(sig);
4896 if (actp != NULL) {
4897 chained = call_chained_handler(actp, sig, siginfo, context);
4898 }
4899 }
4900 return chained;
4901 }
4902
4903 // for diagnostic
4904 int sigflags[NSIG];
4905
4906 int os::Linux::get_our_sigflags(int sig) {
4907 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4908 return sigflags[sig];
4909 }
4910
4911 void os::Linux::set_our_sigflags(int sig, int flags) {
4912 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4913 if (sig > 0 && sig < NSIG) {
4914 sigflags[sig] = flags;
4915 }
4916 }
4917
4918 void os::Linux::set_signal_handler(int sig, bool set_installed) {
4919 // Check for overwrite.
4920 struct sigaction oldAct;
4921 sigaction(sig, (struct sigaction*)NULL, &oldAct);
4922
4923 void* oldhand = oldAct.sa_sigaction
4924 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4925 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4926 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
4927 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
4928 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
4929 if (AllowUserSignalHandlers || !set_installed) {
4930 // Do not overwrite; user takes responsibility to forward to us.
4931 return;
4932 } else if (UseSignalChaining) {
4933 // save the old handler in jvm
4934 os::Posix::save_preinstalled_handler(sig, oldAct);
4935 // libjsig also interposes the sigaction() call below and saves the
4936 // old sigaction on it own.
4937 } else {
4938 fatal("Encountered unexpected pre-existing sigaction handler "
4939 "%#lx for signal %d.", (long)oldhand, sig);
4940 }
4941 }
4942
4943 struct sigaction sigAct;
4944 sigfillset(&(sigAct.sa_mask));
4945 sigAct.sa_handler = SIG_DFL;
4946 if (!set_installed) {
4947 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4948 } else {
4949 sigAct.sa_sigaction = signalHandler;
4950 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4951 }
4952 // Save flags, which are set by ours
4953 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4954 sigflags[sig] = sigAct.sa_flags;
4955
4956 int ret = sigaction(sig, &sigAct, &oldAct);
4957 assert(ret == 0, "check");
4958
4959 void* oldhand2 = oldAct.sa_sigaction
4960 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4961 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4962 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
4963 }
4964
4965 // install signal handlers for signals that HotSpot needs to
4966 // handle in order to support Java-level exception handling.
4967
4968 void os::Linux::install_signal_handlers() {
4969 if (!signal_handlers_are_installed) {
4970 signal_handlers_are_installed = true;
4971
4972 // signal-chaining
4973 typedef void (*signal_setting_t)();
4974 signal_setting_t begin_signal_setting = NULL;
4975 signal_setting_t end_signal_setting = NULL;
4976 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4977 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
4978 if (begin_signal_setting != NULL) {
4979 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4980 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
4981 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
4982 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
4983 libjsig_is_loaded = true;
4984 assert(UseSignalChaining, "should enable signal-chaining");
4985 }
4986 if (libjsig_is_loaded) {
4987 // Tell libjsig jvm is setting signal handlers
4988 (*begin_signal_setting)();
4989 }
4990
4991 set_signal_handler(SIGSEGV, true);
4992 set_signal_handler(SIGPIPE, true);
4993 set_signal_handler(SIGBUS, true);
4994 set_signal_handler(SIGILL, true);
4995 set_signal_handler(SIGFPE, true);
4996 #if defined(PPC64)
4997 set_signal_handler(SIGTRAP, true);
4998 #endif
4999 set_signal_handler(SIGXFSZ, true);
5000
5001 if (libjsig_is_loaded) {
5002 // Tell libjsig jvm finishes setting signal handlers
5003 (*end_signal_setting)();
5004 }
5005
5006 // We don't activate signal checker if libjsig is in place, we trust ourselves
5007 // and if UserSignalHandler is installed all bets are off.
5008 // Log that signal checking is off only if -verbose:jni is specified.
5009 if (CheckJNICalls) {
5010 if (libjsig_is_loaded) {
5011 log_debug(jni, resolve)("Info: libjsig is activated, all active signal checking is disabled");
5012 check_signals = false;
5013 }
5014 if (AllowUserSignalHandlers) {
5015 log_debug(jni, resolve)("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
5016 check_signals = false;
5017 }
5018 }
5019 }
5020 }
5021
5022 // This is the fastest way to get thread cpu time on Linux.
5023 // Returns cpu time (user+sys) for any thread, not only for current.
5024 // POSIX compliant clocks are implemented in the kernels 2.6.16+.
5025 // It might work on 2.6.10+ with a special kernel/glibc patch.
5026 // For reference, please, see IEEE Std 1003.1-2004:
5027 // http://www.unix.org/single_unix_specification
5028
5029 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) {
5030 struct timespec tp;
5031 int rc = os::Posix::clock_gettime(clockid, &tp);
5032 assert(rc == 0, "clock_gettime is expected to return 0 code");
5033
5034 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec;
5035 }
5036
5037 /////
5038 // glibc on Linux platform uses non-documented flag
5039 // to indicate, that some special sort of signal
5040 // trampoline is used.
5041 // We will never set this flag, and we should
5042 // ignore this flag in our diagnostic
5043 #ifdef SIGNIFICANT_SIGNAL_MASK
5044 #undef SIGNIFICANT_SIGNAL_MASK
5045 #endif
5046 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
5047
5048 static const char* get_signal_handler_name(address handler,
5049 char* buf, int buflen) {
5050 int offset = 0;
5051 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
5052 if (found) {
5053 // skip directory names
5054 const char *p1, *p2;
5055 p1 = buf;
5056 size_t len = strlen(os::file_separator());
5057 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
5058 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
5059 } else {
5060 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
5061 }
5062 return buf;
5063 }
5064
5065 static void print_signal_handler(outputStream* st, int sig,
5066 char* buf, size_t buflen) {
5067 struct sigaction sa;
5068
5069 sigaction(sig, NULL, &sa);
5070
5071 // See comment for SIGNIFICANT_SIGNAL_MASK define
5072 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
5073
5074 st->print("%s: ", os::exception_name(sig, buf, buflen));
5075
5076 address handler = (sa.sa_flags & SA_SIGINFO)
5077 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
5078 : CAST_FROM_FN_PTR(address, sa.sa_handler);
5079
5080 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
5081 st->print("SIG_DFL");
5082 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
5083 st->print("SIG_IGN");
5084 } else {
5085 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
5086 }
5087
5088 st->print(", sa_mask[0]=");
5089 os::Posix::print_signal_set_short(st, &sa.sa_mask);
5090
5091 address rh = VMError::get_resetted_sighandler(sig);
5092 // May be, handler was resetted by VMError?
5093 if (rh != NULL) {
5094 handler = rh;
5095 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
5096 }
5097
5098 st->print(", sa_flags=");
5099 os::Posix::print_sa_flags(st, sa.sa_flags);
5100
5101 // Check: is it our handler?
5102 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
5103 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
5104 // It is our signal handler
5105 // check for flags, reset system-used one!
5106 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) {
5107 st->print(
5108 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
5109 os::Linux::get_our_sigflags(sig));
5110 }
5111 }
5112 st->cr();
5113 }
5114
5115
5116 #define DO_SIGNAL_CHECK(sig) \
5117 do { \
5118 if (!sigismember(&check_signal_done, sig)) { \
5119 os::Linux::check_signal_handler(sig); \
5120 } \
5121 } while (0)
5122
5123 // This method is a periodic task to check for misbehaving JNI applications
5124 // under CheckJNI, we can add any periodic checks here
5125
5126 void os::run_periodic_checks() {
5127 if (check_signals == false) return;
5128
5129 // SEGV and BUS if overridden could potentially prevent
5130 // generation of hs*.log in the event of a crash, debugging
5131 // such a case can be very challenging, so we absolutely
5132 // check the following for a good measure:
5133 DO_SIGNAL_CHECK(SIGSEGV);
5134 DO_SIGNAL_CHECK(SIGILL);
5135 DO_SIGNAL_CHECK(SIGFPE);
5136 DO_SIGNAL_CHECK(SIGBUS);
5137 DO_SIGNAL_CHECK(SIGPIPE);
5138 DO_SIGNAL_CHECK(SIGXFSZ);
5139 #if defined(PPC64)
5140 DO_SIGNAL_CHECK(SIGTRAP);
5141 #endif
5142
5143 // ReduceSignalUsage allows the user to override these handlers
5144 // see comments at the very top and jvm_md.h
5145 if (!ReduceSignalUsage) {
5146 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
5147 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
5148 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
5149 DO_SIGNAL_CHECK(BREAK_SIGNAL);
5150 }
5151
5152 DO_SIGNAL_CHECK(SR_signum);
5153 }
5154
5155 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
5156
5157 static os_sigaction_t os_sigaction = NULL;
5158
5159 void os::Linux::check_signal_handler(int sig) {
5160 char buf[O_BUFLEN];
5161 address jvmHandler = NULL;
5162
5163
5164 struct sigaction act;
5165 if (os_sigaction == NULL) {
5166 // only trust the default sigaction, in case it has been interposed
5167 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
5168 if (os_sigaction == NULL) return;
5169 }
5170
5171 os_sigaction(sig, (struct sigaction*)NULL, &act);
5172
5173
5174 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
5175
5176 address thisHandler = (act.sa_flags & SA_SIGINFO)
5177 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
5178 : CAST_FROM_FN_PTR(address, act.sa_handler);
5179
5180
5181 switch (sig) {
5182 case SIGSEGV:
5183 case SIGBUS:
5184 case SIGFPE:
5185 case SIGPIPE:
5186 case SIGILL:
5187 case SIGXFSZ:
5188 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
5189 break;
5190
5191 case SHUTDOWN1_SIGNAL:
5192 case SHUTDOWN2_SIGNAL:
5193 case SHUTDOWN3_SIGNAL:
5194 case BREAK_SIGNAL:
5195 jvmHandler = (address)user_handler();
5196 break;
5197
5198 default:
5199 if (sig == SR_signum) {
5200 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
5201 } else {
5202 return;
5203 }
5204 break;
5205 }
5206
5207 if (thisHandler != jvmHandler) {
5208 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
5209 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
5210 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
5211 // No need to check this sig any longer
5212 sigaddset(&check_signal_done, sig);
5213 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
5214 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
5215 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
5216 exception_name(sig, buf, O_BUFLEN));
5217 }
5218 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) {
5219 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
5220 tty->print("expected:");
5221 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig));
5222 tty->cr();
5223 tty->print(" found:");
5224 os::Posix::print_sa_flags(tty, act.sa_flags);
5225 tty->cr();
5226 // No need to check this sig any longer
5227 sigaddset(&check_signal_done, sig);
5228 }
5229
5230 // Dump all the signal
5231 if (sigismember(&check_signal_done, sig)) {
5232 print_signal_handlers(tty, buf, O_BUFLEN);
5233 }
5234 }
5235
5236 extern void report_error(char* file_name, int line_no, char* title,
5237 char* format, ...);
5238
5239 // this is called _before_ most of the global arguments have been parsed
5240 void os::init(void) {
5241 char dummy; // used to get a guess on initial stack address
5242
5243 clock_tics_per_sec = sysconf(_SC_CLK_TCK);
5244
5245 init_random(1234567);
5246
5247 Linux::set_page_size(sysconf(_SC_PAGESIZE));
5248 if (Linux::page_size() == -1) {
5249 fatal("os_linux.cpp: os::init: sysconf failed (%s)",
5250 os::strerror(errno));
5251 }
5252 init_page_sizes((size_t) Linux::page_size());
5253
5254 Linux::initialize_system_info();
5255
5256 os::Linux::CPUPerfTicks pticks;
5257 bool res = os::Linux::get_tick_information(&pticks, -1);
5258
5259 if (res && pticks.has_steal_ticks) {
5260 has_initial_tick_info = true;
5261 initial_total_ticks = pticks.total;
5262 initial_steal_ticks = pticks.steal;
5263 }
5264
5265 // _main_thread points to the thread that created/loaded the JVM.
5266 Linux::_main_thread = pthread_self();
5267
5268 // retrieve entry point for pthread_setname_np
5269 Linux::_pthread_setname_np =
5270 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np");
5271
5272 os::Posix::init();
5273
5274 initial_time_count = javaTimeNanos();
5275
5276 // Always warn if no monotonic clock available
5277 if (!os::Posix::supports_monotonic_clock()) {
5278 warning("No monotonic clock was available - timed services may " \
5279 "be adversely affected if the time-of-day clock changes");
5280 }
5281 }
5282
5283 // To install functions for atexit system call
5284 extern "C" {
5285 static void perfMemory_exit_helper() {
5286 perfMemory_exit();
5287 }
5288 }
5289
5290 void os::pd_init_container_support() {
5291 OSContainer::init();
5292 }
5293
5294 void os::Linux::numa_init() {
5295
5296 // Java can be invoked as
5297 // 1. Without numactl and heap will be allocated/configured on all nodes as
5298 // per the system policy.
5299 // 2. With numactl --interleave:
5300 // Use numa_get_interleave_mask(v2) API to get nodes bitmask. The same
5301 // API for membind case bitmask is reset.
5302 // Interleave is only hint and Kernel can fallback to other nodes if
5303 // no memory is available on the target nodes.
5304 // 3. With numactl --membind:
5305 // Use numa_get_membind(v2) API to get nodes bitmask. The same API for
5306 // interleave case returns bitmask of all nodes.
5307 // numa_all_nodes_ptr holds bitmask of all nodes.
5308 // numa_get_interleave_mask(v2) and numa_get_membind(v2) APIs returns correct
5309 // bitmask when externally configured to run on all or fewer nodes.
5310
5311 if (!Linux::libnuma_init()) {
5312 FLAG_SET_ERGO(UseNUMA, false);
5313 FLAG_SET_ERGO(UseNUMAInterleaving, false); // Also depends on libnuma.
5314 } else {
5315 if ((Linux::numa_max_node() < 1) || Linux::is_bound_to_single_node()) {
5316 // If there's only one node (they start from 0) or if the process
5317 // is bound explicitly to a single node using membind, disable NUMA
5318 UseNUMA = false;
5319 } else {
5320 LogTarget(Info,os) log;
5321 LogStream ls(log);
5322
5323 Linux::set_configured_numa_policy(Linux::identify_numa_policy());
5324
5325 struct bitmask* bmp = Linux::_numa_membind_bitmask;
5326 const char* numa_mode = "membind";
5327
5328 if (Linux::is_running_in_interleave_mode()) {
5329 bmp = Linux::_numa_interleave_bitmask;
5330 numa_mode = "interleave";
5331 }
5332
5333 ls.print("UseNUMA is enabled and invoked in '%s' mode."
5334 " Heap will be configured using NUMA memory nodes:", numa_mode);
5335
5336 for (int node = 0; node <= Linux::numa_max_node(); node++) {
5337 if (Linux::_numa_bitmask_isbitset(bmp, node)) {
5338 ls.print(" %d", node);
5339 }
5340 }
5341 }
5342 }
5343
5344 // When NUMA requested, not-NUMA-aware allocations default to interleaving.
5345 if (UseNUMA && !UseNUMAInterleaving) {
5346 FLAG_SET_ERGO_IF_DEFAULT(UseNUMAInterleaving, true);
5347 }
5348
5349 if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) {
5350 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way
5351 // we can make the adaptive lgrp chunk resizing work. If the user specified both
5352 // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn
5353 // and disable adaptive resizing.
5354 if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) {
5355 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, "
5356 "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)");
5357 UseAdaptiveSizePolicy = false;
5358 UseAdaptiveNUMAChunkSizing = false;
5359 }
5360 }
5361 }
5362
5363 // this is called _after_ the global arguments have been parsed
5364 jint os::init_2(void) {
5365
5366 // This could be set after os::Posix::init() but all platforms
5367 // have to set it the same so we have to mirror Solaris.
5368 DEBUG_ONLY(os::set_mutex_init_done();)
5369
5370 os::Posix::init_2();
5371
5372 Linux::fast_thread_clock_init();
5373
5374 // initialize suspend/resume support - must do this before signal_sets_init()
5375 if (SR_initialize() != 0) {
5376 perror("SR_initialize failed");
5377 return JNI_ERR;
5378 }
5379
5380 Linux::signal_sets_init();
5381 Linux::install_signal_handlers();
5382 // Initialize data for jdk.internal.misc.Signal
5383 if (!ReduceSignalUsage) {
5384 jdk_misc_signal_init();
5385 }
5386
5387 if (AdjustStackSizeForTLS) {
5388 get_minstack_init();
5389 }
5390
5391 // Check and sets minimum stack sizes against command line options
5392 if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
5393 return JNI_ERR;
5394 }
5395
5396 #if defined(IA32)
5397 // Need to ensure we've determined the process's initial stack to
5398 // perform the workaround
5399 Linux::capture_initial_stack(JavaThread::stack_size_at_create());
5400 workaround_expand_exec_shield_cs_limit();
5401 #else
5402 suppress_primordial_thread_resolution = Arguments::created_by_java_launcher();
5403 if (!suppress_primordial_thread_resolution) {
5404 Linux::capture_initial_stack(JavaThread::stack_size_at_create());
5405 }
5406 #endif
5407
5408 Linux::libpthread_init();
5409 Linux::sched_getcpu_init();
5410 log_info(os)("HotSpot is running with %s, %s",
5411 Linux::glibc_version(), Linux::libpthread_version());
5412
5413 if (UseNUMA || UseNUMAInterleaving) {
5414 Linux::numa_init();
5415 }
5416
5417 if (MaxFDLimit) {
5418 // set the number of file descriptors to max. print out error
5419 // if getrlimit/setrlimit fails but continue regardless.
5420 struct rlimit nbr_files;
5421 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
5422 if (status != 0) {
5423 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
5424 } else {
5425 nbr_files.rlim_cur = nbr_files.rlim_max;
5426 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
5427 if (status != 0) {
5428 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
5429 }
5430 }
5431 }
5432
5433 // at-exit methods are called in the reverse order of their registration.
5434 // atexit functions are called on return from main or as a result of a
5435 // call to exit(3C). There can be only 32 of these functions registered
5436 // and atexit() does not set errno.
5437
5438 if (PerfAllowAtExitRegistration) {
5439 // only register atexit functions if PerfAllowAtExitRegistration is set.
5440 // atexit functions can be delayed until process exit time, which
5441 // can be problematic for embedded VM situations. Embedded VMs should
5442 // call DestroyJavaVM() to assure that VM resources are released.
5443
5444 // note: perfMemory_exit_helper atexit function may be removed in
5445 // the future if the appropriate cleanup code can be added to the
5446 // VM_Exit VMOperation's doit method.
5447 if (atexit(perfMemory_exit_helper) != 0) {
5448 warning("os::init_2 atexit(perfMemory_exit_helper) failed");
5449 }
5450 }
5451
5452 // initialize thread priority policy
5453 prio_init();
5454
5455 if (!FLAG_IS_DEFAULT(AllocateHeapAt) || !FLAG_IS_DEFAULT(AllocateOldGenAt)) {
5456 set_coredump_filter(DAX_SHARED_BIT);
5457 }
5458
5459 if (DumpPrivateMappingsInCore) {
5460 set_coredump_filter(FILE_BACKED_PVT_BIT);
5461 }
5462
5463 if (DumpSharedMappingsInCore) {
5464 set_coredump_filter(FILE_BACKED_SHARED_BIT);
5465 }
5466
5467 return JNI_OK;
5468 }
5469
5470 // older glibc versions don't have this macro (which expands to
5471 // an optimized bit-counting function) so we have to roll our own
5472 #ifndef CPU_COUNT
5473
5474 static int _cpu_count(const cpu_set_t* cpus) {
5475 int count = 0;
5476 // only look up to the number of configured processors
5477 for (int i = 0; i < os::processor_count(); i++) {
5478 if (CPU_ISSET(i, cpus)) {
5479 count++;
5480 }
5481 }
5482 return count;
5483 }
5484
5485 #define CPU_COUNT(cpus) _cpu_count(cpus)
5486
5487 #endif // CPU_COUNT
5488
5489 // Get the current number of available processors for this process.
5490 // This value can change at any time during a process's lifetime.
5491 // sched_getaffinity gives an accurate answer as it accounts for cpusets.
5492 // If it appears there may be more than 1024 processors then we do a
5493 // dynamic check - see 6515172 for details.
5494 // If anything goes wrong we fallback to returning the number of online
5495 // processors - which can be greater than the number available to the process.
5496 int os::Linux::active_processor_count() {
5497 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors
5498 cpu_set_t* cpus_p = &cpus;
5499 int cpus_size = sizeof(cpu_set_t);
5500
5501 int configured_cpus = os::processor_count(); // upper bound on available cpus
5502 int cpu_count = 0;
5503
5504 // old build platforms may not support dynamic cpu sets
5505 #ifdef CPU_ALLOC
5506
5507 // To enable easy testing of the dynamic path on different platforms we
5508 // introduce a diagnostic flag: UseCpuAllocPath
5509 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) {
5510 // kernel may use a mask bigger than cpu_set_t
5511 log_trace(os)("active_processor_count: using dynamic path %s"
5512 "- configured processors: %d",
5513 UseCpuAllocPath ? "(forced) " : "",
5514 configured_cpus);
5515 cpus_p = CPU_ALLOC(configured_cpus);
5516 if (cpus_p != NULL) {
5517 cpus_size = CPU_ALLOC_SIZE(configured_cpus);
5518 // zero it just to be safe
5519 CPU_ZERO_S(cpus_size, cpus_p);
5520 }
5521 else {
5522 // failed to allocate so fallback to online cpus
5523 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
5524 log_trace(os)("active_processor_count: "
5525 "CPU_ALLOC failed (%s) - using "
5526 "online processor count: %d",
5527 os::strerror(errno), online_cpus);
5528 return online_cpus;
5529 }
5530 }
5531 else {
5532 log_trace(os)("active_processor_count: using static path - configured processors: %d",
5533 configured_cpus);
5534 }
5535 #else // CPU_ALLOC
5536 // these stubs won't be executed
5537 #define CPU_COUNT_S(size, cpus) -1
5538 #define CPU_FREE(cpus)
5539
5540 log_trace(os)("active_processor_count: only static path available - configured processors: %d",
5541 configured_cpus);
5542 #endif // CPU_ALLOC
5543
5544 // pid 0 means the current thread - which we have to assume represents the process
5545 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) {
5546 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5547 cpu_count = CPU_COUNT_S(cpus_size, cpus_p);
5548 }
5549 else {
5550 cpu_count = CPU_COUNT(cpus_p);
5551 }
5552 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count);
5553 }
5554 else {
5555 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN);
5556 warning("sched_getaffinity failed (%s)- using online processor count (%d) "
5557 "which may exceed available processors", os::strerror(errno), cpu_count);
5558 }
5559
5560 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5561 CPU_FREE(cpus_p);
5562 }
5563
5564 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check");
5565 return cpu_count;
5566 }
5567
5568 // Determine the active processor count from one of
5569 // three different sources:
5570 //
5571 // 1. User option -XX:ActiveProcessorCount
5572 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN)
5573 // 3. extracted from cgroup cpu subsystem (shares and quotas)
5574 //
5575 // Option 1, if specified, will always override.
5576 // If the cgroup subsystem is active and configured, we
5577 // will return the min of the cgroup and option 2 results.
5578 // This is required since tools, such as numactl, that
5579 // alter cpu affinity do not update cgroup subsystem
5580 // cpuset configuration files.
5581 int os::active_processor_count() {
5582 // User has overridden the number of active processors
5583 if (ActiveProcessorCount > 0) {
5584 log_trace(os)("active_processor_count: "
5585 "active processor count set by user : %d",
5586 ActiveProcessorCount);
5587 return ActiveProcessorCount;
5588 }
5589
5590 int active_cpus;
5591 if (OSContainer::is_containerized()) {
5592 active_cpus = OSContainer::active_processor_count();
5593 log_trace(os)("active_processor_count: determined by OSContainer: %d",
5594 active_cpus);
5595 } else {
5596 active_cpus = os::Linux::active_processor_count();
5597 }
5598
5599 return active_cpus;
5600 }
5601
5602 uint os::processor_id() {
5603 const int id = Linux::sched_getcpu();
5604 assert(id >= 0 && id < _processor_count, "Invalid processor id");
5605 return (uint)id;
5606 }
5607
5608 void os::set_native_thread_name(const char *name) {
5609 if (Linux::_pthread_setname_np) {
5610 char buf [16]; // according to glibc manpage, 16 chars incl. '/0'
5611 snprintf(buf, sizeof(buf), "%s", name);
5612 buf[sizeof(buf) - 1] = '\0';
5613 const int rc = Linux::_pthread_setname_np(pthread_self(), buf);
5614 // ERANGE should not happen; all other errors should just be ignored.
5615 assert(rc != ERANGE, "pthread_setname_np failed");
5616 }
5617 }
5618
5619 bool os::bind_to_processor(uint processor_id) {
5620 // Not yet implemented.
5621 return false;
5622 }
5623
5624 ///
5625
5626 void os::SuspendedThreadTask::internal_do_task() {
5627 if (do_suspend(_thread->osthread())) {
5628 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
5629 do_task(context);
5630 do_resume(_thread->osthread());
5631 }
5632 }
5633
5634 ////////////////////////////////////////////////////////////////////////////////
5635 // debug support
5636
5637 bool os::find(address addr, outputStream* st) {
5638 Dl_info dlinfo;
5639 memset(&dlinfo, 0, sizeof(dlinfo));
5640 if (dladdr(addr, &dlinfo) != 0) {
5641 st->print(PTR_FORMAT ": ", p2i(addr));
5642 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
5643 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname,
5644 p2i(addr) - p2i(dlinfo.dli_saddr));
5645 } else if (dlinfo.dli_fbase != NULL) {
5646 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase));
5647 } else {
5648 st->print("<absolute address>");
5649 }
5650 if (dlinfo.dli_fname != NULL) {
5651 st->print(" in %s", dlinfo.dli_fname);
5652 }
5653 if (dlinfo.dli_fbase != NULL) {
5654 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase));
5655 }
5656 st->cr();
5657
5658 if (Verbose) {
5659 // decode some bytes around the PC
5660 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
5661 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
5662 address lowest = (address) dlinfo.dli_sname;
5663 if (!lowest) lowest = (address) dlinfo.dli_fbase;
5664 if (begin < lowest) begin = lowest;
5665 Dl_info dlinfo2;
5666 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
5667 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
5668 end = (address) dlinfo2.dli_saddr;
5669 }
5670 Disassembler::decode(begin, end, st);
5671 }
5672 return true;
5673 }
5674 return false;
5675 }
5676
5677 ////////////////////////////////////////////////////////////////////////////////
5678 // misc
5679
5680 // This does not do anything on Linux. This is basically a hook for being
5681 // able to use structured exception handling (thread-local exception filters)
5682 // on, e.g., Win32.
5683 void
5684 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
5685 JavaCallArguments* args, Thread* thread) {
5686 f(value, method, args, thread);
5687 }
5688
5689 void os::print_statistics() {
5690 }
5691
5692 bool os::message_box(const char* title, const char* message) {
5693 int i;
5694 fdStream err(defaultStream::error_fd());
5695 for (i = 0; i < 78; i++) err.print_raw("=");
5696 err.cr();
5697 err.print_raw_cr(title);
5698 for (i = 0; i < 78; i++) err.print_raw("-");
5699 err.cr();
5700 err.print_raw_cr(message);
5701 for (i = 0; i < 78; i++) err.print_raw("=");
5702 err.cr();
5703
5704 char buf[16];
5705 // Prevent process from exiting upon "read error" without consuming all CPU
5706 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
5707
5708 return buf[0] == 'y' || buf[0] == 'Y';
5709 }
5710
5711 // Is a (classpath) directory empty?
5712 bool os::dir_is_empty(const char* path) {
5713 DIR *dir = NULL;
5714 struct dirent *ptr;
5715
5716 dir = opendir(path);
5717 if (dir == NULL) return true;
5718
5719 // Scan the directory
5720 bool result = true;
5721 while (result && (ptr = readdir(dir)) != NULL) {
5722 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
5723 result = false;
5724 }
5725 }
5726 closedir(dir);
5727 return result;
5728 }
5729
5730 // This code originates from JDK's sysOpen and open64_w
5731 // from src/solaris/hpi/src/system_md.c
5732
5733 int os::open(const char *path, int oflag, int mode) {
5734 if (strlen(path) > MAX_PATH - 1) {
5735 errno = ENAMETOOLONG;
5736 return -1;
5737 }
5738
5739 // All file descriptors that are opened in the Java process and not
5740 // specifically destined for a subprocess should have the close-on-exec
5741 // flag set. If we don't set it, then careless 3rd party native code
5742 // might fork and exec without closing all appropriate file descriptors
5743 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in
5744 // turn might:
5745 //
5746 // - cause end-of-file to fail to be detected on some file
5747 // descriptors, resulting in mysterious hangs, or
5748 //
5749 // - might cause an fopen in the subprocess to fail on a system
5750 // suffering from bug 1085341.
5751 //
5752 // (Yes, the default setting of the close-on-exec flag is a Unix
5753 // design flaw)
5754 //
5755 // See:
5756 // 1085341: 32-bit stdio routines should support file descriptors >255
5757 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
5758 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
5759 //
5760 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open().
5761 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor
5762 // because it saves a system call and removes a small window where the flag
5763 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored
5764 // and we fall back to using FD_CLOEXEC (see below).
5765 #ifdef O_CLOEXEC
5766 oflag |= O_CLOEXEC;
5767 #endif
5768
5769 int fd = ::open64(path, oflag, mode);
5770 if (fd == -1) return -1;
5771
5772 //If the open succeeded, the file might still be a directory
5773 {
5774 struct stat64 buf64;
5775 int ret = ::fstat64(fd, &buf64);
5776 int st_mode = buf64.st_mode;
5777
5778 if (ret != -1) {
5779 if ((st_mode & S_IFMT) == S_IFDIR) {
5780 errno = EISDIR;
5781 ::close(fd);
5782 return -1;
5783 }
5784 } else {
5785 ::close(fd);
5786 return -1;
5787 }
5788 }
5789
5790 #ifdef FD_CLOEXEC
5791 // Validate that the use of the O_CLOEXEC flag on open above worked.
5792 // With recent kernels, we will perform this check exactly once.
5793 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
5794 if (!O_CLOEXEC_is_known_to_work) {
5795 int flags = ::fcntl(fd, F_GETFD);
5796 if (flags != -1) {
5797 if ((flags & FD_CLOEXEC) != 0)
5798 O_CLOEXEC_is_known_to_work = 1;
5799 else
5800 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
5801 }
5802 }
5803 #endif
5804
5805 return fd;
5806 }
5807
5808
5809 // create binary file, rewriting existing file if required
5810 int os::create_binary_file(const char* path, bool rewrite_existing) {
5811 int oflags = O_WRONLY | O_CREAT;
5812 if (!rewrite_existing) {
5813 oflags |= O_EXCL;
5814 }
5815 return ::open64(path, oflags, S_IREAD | S_IWRITE);
5816 }
5817
5818 // return current position of file pointer
5819 jlong os::current_file_offset(int fd) {
5820 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
5821 }
5822
5823 // move file pointer to the specified offset
5824 jlong os::seek_to_file_offset(int fd, jlong offset) {
5825 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
5826 }
5827
5828 // This code originates from JDK's sysAvailable
5829 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
5830
5831 int os::available(int fd, jlong *bytes) {
5832 jlong cur, end;
5833 int mode;
5834 struct stat64 buf64;
5835
5836 if (::fstat64(fd, &buf64) >= 0) {
5837 mode = buf64.st_mode;
5838 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
5839 int n;
5840 if (::ioctl(fd, FIONREAD, &n) >= 0) {
5841 *bytes = n;
5842 return 1;
5843 }
5844 }
5845 }
5846 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
5847 return 0;
5848 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
5849 return 0;
5850 } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
5851 return 0;
5852 }
5853 *bytes = end - cur;
5854 return 1;
5855 }
5856
5857 // Map a block of memory.
5858 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
5859 char *addr, size_t bytes, bool read_only,
5860 bool allow_exec) {
5861 int prot;
5862 int flags = MAP_PRIVATE;
5863
5864 if (read_only) {
5865 prot = PROT_READ;
5866 } else {
5867 prot = PROT_READ | PROT_WRITE;
5868 }
5869
5870 if (allow_exec) {
5871 prot |= PROT_EXEC;
5872 }
5873
5874 if (addr != NULL) {
5875 flags |= MAP_FIXED;
5876 }
5877
5878 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
5879 fd, file_offset);
5880 if (mapped_address == MAP_FAILED) {
5881 return NULL;
5882 }
5883 return mapped_address;
5884 }
5885
5886
5887 // Remap a block of memory.
5888 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
5889 char *addr, size_t bytes, bool read_only,
5890 bool allow_exec) {
5891 // same as map_memory() on this OS
5892 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
5893 allow_exec);
5894 }
5895
5896
5897 // Unmap a block of memory.
5898 bool os::pd_unmap_memory(char* addr, size_t bytes) {
5899 return munmap(addr, bytes) == 0;
5900 }
5901
5902 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time);
5903
5904 static jlong fast_cpu_time(Thread *thread) {
5905 clockid_t clockid;
5906 int rc = os::Linux::pthread_getcpuclockid(thread->osthread()->pthread_id(),
5907 &clockid);
5908 if (rc == 0) {
5909 return os::Linux::fast_thread_cpu_time(clockid);
5910 } else {
5911 // It's possible to encounter a terminated native thread that failed
5912 // to detach itself from the VM - which should result in ESRCH.
5913 assert_status(rc == ESRCH, rc, "pthread_getcpuclockid failed");
5914 return -1;
5915 }
5916 }
5917
5918 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
5919 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
5920 // of a thread.
5921 //
5922 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
5923 // the fast estimate available on the platform.
5924
5925 jlong os::current_thread_cpu_time() {
5926 if (os::Linux::supports_fast_thread_cpu_time()) {
5927 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5928 } else {
5929 // return user + sys since the cost is the same
5930 return slow_thread_cpu_time(Thread::current(), true /* user + sys */);
5931 }
5932 }
5933
5934 jlong os::thread_cpu_time(Thread* thread) {
5935 // consistent with what current_thread_cpu_time() returns
5936 if (os::Linux::supports_fast_thread_cpu_time()) {
5937 return fast_cpu_time(thread);
5938 } else {
5939 return slow_thread_cpu_time(thread, true /* user + sys */);
5940 }
5941 }
5942
5943 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
5944 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5945 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5946 } else {
5947 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time);
5948 }
5949 }
5950
5951 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5952 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5953 return fast_cpu_time(thread);
5954 } else {
5955 return slow_thread_cpu_time(thread, user_sys_cpu_time);
5956 }
5957 }
5958
5959 // -1 on error.
5960 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5961 pid_t tid = thread->osthread()->thread_id();
5962 char *s;
5963 char stat[2048];
5964 int statlen;
5965 char proc_name[64];
5966 int count;
5967 long sys_time, user_time;
5968 char cdummy;
5969 int idummy;
5970 long ldummy;
5971 FILE *fp;
5972
5973 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid);
5974 fp = fopen(proc_name, "r");
5975 if (fp == NULL) return -1;
5976 statlen = fread(stat, 1, 2047, fp);
5977 stat[statlen] = '\0';
5978 fclose(fp);
5979
5980 // Skip pid and the command string. Note that we could be dealing with
5981 // weird command names, e.g. user could decide to rename java launcher
5982 // to "java 1.4.2 :)", then the stat file would look like
5983 // 1234 (java 1.4.2 :)) R ... ...
5984 // We don't really need to know the command string, just find the last
5985 // occurrence of ")" and then start parsing from there. See bug 4726580.
5986 s = strrchr(stat, ')');
5987 if (s == NULL) return -1;
5988
5989 // Skip blank chars
5990 do { s++; } while (s && isspace(*s));
5991
5992 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu",
5993 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy,
5994 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy,
5995 &user_time, &sys_time);
5996 if (count != 13) return -1;
5997 if (user_sys_cpu_time) {
5998 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
5999 } else {
6000 return (jlong)user_time * (1000000000 / clock_tics_per_sec);
6001 }
6002 }
6003
6004 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
6005 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
6006 info_ptr->may_skip_backward = false; // elapsed time not wall time
6007 info_ptr->may_skip_forward = false; // elapsed time not wall time
6008 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
6009 }
6010
6011 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
6012 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
6013 info_ptr->may_skip_backward = false; // elapsed time not wall time
6014 info_ptr->may_skip_forward = false; // elapsed time not wall time
6015 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
6016 }
6017
6018 bool os::is_thread_cpu_time_supported() {
6019 return true;
6020 }
6021
6022 // System loadavg support. Returns -1 if load average cannot be obtained.
6023 // Linux doesn't yet have a (official) notion of processor sets,
6024 // so just return the system wide load average.
6025 int os::loadavg(double loadavg[], int nelem) {
6026 return ::getloadavg(loadavg, nelem);
6027 }
6028
6029 void os::pause() {
6030 char filename[MAX_PATH];
6031 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
6032 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
6033 } else {
6034 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
6035 }
6036
6037 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
6038 if (fd != -1) {
6039 struct stat buf;
6040 ::close(fd);
6041 while (::stat(filename, &buf) == 0) {
6042 (void)::poll(NULL, 0, 100);
6043 }
6044 } else {
6045 jio_fprintf(stderr,
6046 "Could not open pause file '%s', continuing immediately.\n", filename);
6047 }
6048 }
6049
6050 extern char** environ;
6051
6052 // Run the specified command in a separate process. Return its exit value,
6053 // or -1 on failure (e.g. can't fork a new process).
6054 // Unlike system(), this function can be called from signal handler. It
6055 // doesn't block SIGINT et al.
6056 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
6057 const char * argv[4] = {"sh", "-c", cmd, NULL};
6058
6059 pid_t pid ;
6060
6061 if (use_vfork_if_available) {
6062 pid = vfork();
6063 } else {
6064 pid = fork();
6065 }
6066
6067 if (pid < 0) {
6068 // fork failed
6069 return -1;
6070
6071 } else if (pid == 0) {
6072 // child process
6073
6074 execve("/bin/sh", (char* const*)argv, environ);
6075
6076 // execve failed
6077 _exit(-1);
6078
6079 } else {
6080 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
6081 // care about the actual exit code, for now.
6082
6083 int status;
6084
6085 // Wait for the child process to exit. This returns immediately if
6086 // the child has already exited. */
6087 while (waitpid(pid, &status, 0) < 0) {
6088 switch (errno) {
6089 case ECHILD: return 0;
6090 case EINTR: break;
6091 default: return -1;
6092 }
6093 }
6094
6095 if (WIFEXITED(status)) {
6096 // The child exited normally; get its exit code.
6097 return WEXITSTATUS(status);
6098 } else if (WIFSIGNALED(status)) {
6099 // The child exited because of a signal
6100 // The best value to return is 0x80 + signal number,
6101 // because that is what all Unix shells do, and because
6102 // it allows callers to distinguish between process exit and
6103 // process death by signal.
6104 return 0x80 + WTERMSIG(status);
6105 } else {
6106 // Unknown exit code; pass it through
6107 return status;
6108 }
6109 }
6110 }
6111
6112 // Get the default path to the core file
6113 // Returns the length of the string
6114 int os::get_core_path(char* buffer, size_t bufferSize) {
6115 /*
6116 * Max length of /proc/sys/kernel/core_pattern is 128 characters.
6117 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
6118 */
6119 const int core_pattern_len = 129;
6120 char core_pattern[core_pattern_len] = {0};
6121
6122 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY);
6123 if (core_pattern_file == -1) {
6124 return -1;
6125 }
6126
6127 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len);
6128 ::close(core_pattern_file);
6129 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') {
6130 return -1;
6131 }
6132 if (core_pattern[ret-1] == '\n') {
6133 core_pattern[ret-1] = '\0';
6134 } else {
6135 core_pattern[ret] = '\0';
6136 }
6137
6138 // Replace the %p in the core pattern with the process id. NOTE: we do this
6139 // only if the pattern doesn't start with "|", and we support only one %p in
6140 // the pattern.
6141 char *pid_pos = strstr(core_pattern, "%p");
6142 const char* tail = (pid_pos != NULL) ? (pid_pos + 2) : ""; // skip over the "%p"
6143 int written;
6144
6145 if (core_pattern[0] == '/') {
6146 if (pid_pos != NULL) {
6147 *pid_pos = '\0';
6148 written = jio_snprintf(buffer, bufferSize, "%s%d%s", core_pattern,
6149 current_process_id(), tail);
6150 } else {
6151 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern);
6152 }
6153 } else {
6154 char cwd[PATH_MAX];
6155
6156 const char* p = get_current_directory(cwd, PATH_MAX);
6157 if (p == NULL) {
6158 return -1;
6159 }
6160
6161 if (core_pattern[0] == '|') {
6162 written = jio_snprintf(buffer, bufferSize,
6163 "\"%s\" (or dumping to %s/core.%d)",
6164 &core_pattern[1], p, current_process_id());
6165 } else if (pid_pos != NULL) {
6166 *pid_pos = '\0';
6167 written = jio_snprintf(buffer, bufferSize, "%s/%s%d%s", p, core_pattern,
6168 current_process_id(), tail);
6169 } else {
6170 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern);
6171 }
6172 }
6173
6174 if (written < 0) {
6175 return -1;
6176 }
6177
6178 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) {
6179 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY);
6180
6181 if (core_uses_pid_file != -1) {
6182 char core_uses_pid = 0;
6183 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1);
6184 ::close(core_uses_pid_file);
6185
6186 if (core_uses_pid == '1') {
6187 jio_snprintf(buffer + written, bufferSize - written,
6188 ".%d", current_process_id());
6189 }
6190 }
6191 }
6192
6193 return strlen(buffer);
6194 }
6195
6196 bool os::start_debugging(char *buf, int buflen) {
6197 int len = (int)strlen(buf);
6198 char *p = &buf[len];
6199
6200 jio_snprintf(p, buflen-len,
6201 "\n\n"
6202 "Do you want to debug the problem?\n\n"
6203 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n"
6204 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
6205 "Otherwise, press RETURN to abort...",
6206 os::current_process_id(), os::current_process_id(),
6207 os::current_thread_id(), os::current_thread_id());
6208
6209 bool yes = os::message_box("Unexpected Error", buf);
6210
6211 if (yes) {
6212 // yes, user asked VM to launch debugger
6213 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d",
6214 os::current_process_id(), os::current_process_id());
6215
6216 os::fork_and_exec(buf);
6217 yes = false;
6218 }
6219 return yes;
6220 }
6221
6222
6223 // Java/Compiler thread:
6224 //
6225 // Low memory addresses
6226 // P0 +------------------------+
6227 // | |\ Java thread created by VM does not have glibc
6228 // | glibc guard page | - guard page, attached Java thread usually has
6229 // | |/ 1 glibc guard page.
6230 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
6231 // | |\
6232 // | HotSpot Guard Pages | - red, yellow and reserved pages
6233 // | |/
6234 // +------------------------+ JavaThread::stack_reserved_zone_base()
6235 // | |\
6236 // | Normal Stack | -
6237 // | |/
6238 // P2 +------------------------+ Thread::stack_base()
6239 //
6240 // Non-Java thread:
6241 //
6242 // Low memory addresses
6243 // P0 +------------------------+
6244 // | |\
6245 // | glibc guard page | - usually 1 page
6246 // | |/
6247 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
6248 // | |\
6249 // | Normal Stack | -
6250 // | |/
6251 // P2 +------------------------+ Thread::stack_base()
6252 //
6253 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size
6254 // returned from pthread_attr_getstack().
6255 // ** Due to NPTL implementation error, linux takes the glibc guard page out
6256 // of the stack size given in pthread_attr. We work around this for
6257 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.)
6258 //
6259 #ifndef ZERO
6260 static void current_stack_region(address * bottom, size_t * size) {
6261 if (os::is_primordial_thread()) {
6262 // primordial thread needs special handling because pthread_getattr_np()
6263 // may return bogus value.
6264 *bottom = os::Linux::initial_thread_stack_bottom();
6265 *size = os::Linux::initial_thread_stack_size();
6266 } else {
6267 pthread_attr_t attr;
6268
6269 int rslt = pthread_getattr_np(pthread_self(), &attr);
6270
6271 // JVM needs to know exact stack location, abort if it fails
6272 if (rslt != 0) {
6273 if (rslt == ENOMEM) {
6274 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
6275 } else {
6276 fatal("pthread_getattr_np failed with error = %d", rslt);
6277 }
6278 }
6279
6280 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
6281 fatal("Cannot locate current stack attributes!");
6282 }
6283
6284 // Work around NPTL stack guard error.
6285 size_t guard_size = 0;
6286 rslt = pthread_attr_getguardsize(&attr, &guard_size);
6287 if (rslt != 0) {
6288 fatal("pthread_attr_getguardsize failed with error = %d", rslt);
6289 }
6290 *bottom += guard_size;
6291 *size -= guard_size;
6292
6293 pthread_attr_destroy(&attr);
6294
6295 }
6296 assert(os::current_stack_pointer() >= *bottom &&
6297 os::current_stack_pointer() < *bottom + *size, "just checking");
6298 }
6299
6300 address os::current_stack_base() {
6301 address bottom;
6302 size_t size;
6303 current_stack_region(&bottom, &size);
6304 return (bottom + size);
6305 }
6306
6307 size_t os::current_stack_size() {
6308 // This stack size includes the usable stack and HotSpot guard pages
6309 // (for the threads that have Hotspot guard pages).
6310 address bottom;
6311 size_t size;
6312 current_stack_region(&bottom, &size);
6313 return size;
6314 }
6315 #endif
6316
6317 static inline struct timespec get_mtime(const char* filename) {
6318 struct stat st;
6319 int ret = os::stat(filename, &st);
6320 assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
6321 return st.st_mtim;
6322 }
6323
6324 int os::compare_file_modified_times(const char* file1, const char* file2) {
6325 struct timespec filetime1 = get_mtime(file1);
6326 struct timespec filetime2 = get_mtime(file2);
6327 int diff = filetime1.tv_sec - filetime2.tv_sec;
6328 if (diff == 0) {
6329 return filetime1.tv_nsec - filetime2.tv_nsec;
6330 }
6331 return diff;
6332 }
6333
6334 bool os::supports_map_sync() {
6335 return true;
6336 }
6337
6338 /////////////// Unit tests ///////////////
6339
6340 #ifndef PRODUCT
6341
6342 class TestReserveMemorySpecial : AllStatic {
6343 public:
6344 static void small_page_write(void* addr, size_t size) {
6345 size_t page_size = os::vm_page_size();
6346
6347 char* end = (char*)addr + size;
6348 for (char* p = (char*)addr; p < end; p += page_size) {
6349 *p = 1;
6350 }
6351 }
6352
6353 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) {
6354 if (!UseHugeTLBFS) {
6355 return;
6356 }
6357
6358 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false);
6359
6360 if (addr != NULL) {
6361 small_page_write(addr, size);
6362
6363 os::Linux::release_memory_special_huge_tlbfs(addr, size);
6364 }
6365 }
6366
6367 static void test_reserve_memory_special_huge_tlbfs_only() {
6368 if (!UseHugeTLBFS) {
6369 return;
6370 }
6371
6372 size_t lp = os::large_page_size();
6373
6374 for (size_t size = lp; size <= lp * 10; size += lp) {
6375 test_reserve_memory_special_huge_tlbfs_only(size);
6376 }
6377 }
6378
6379 static void test_reserve_memory_special_huge_tlbfs_mixed() {
6380 size_t lp = os::large_page_size();
6381 size_t ag = os::vm_allocation_granularity();
6382
6383 // sizes to test
6384 const size_t sizes[] = {
6385 lp, lp + ag, lp + lp / 2, lp * 2,
6386 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2,
6387 lp * 10, lp * 10 + lp / 2
6388 };
6389 const int num_sizes = sizeof(sizes) / sizeof(size_t);
6390
6391 // For each size/alignment combination, we test three scenarios:
6392 // 1) with req_addr == NULL
6393 // 2) with a non-null req_addr at which we expect to successfully allocate
6394 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we
6395 // expect the allocation to either fail or to ignore req_addr
6396
6397 // Pre-allocate two areas; they shall be as large as the largest allocation
6398 // and aligned to the largest alignment we will be testing.
6399 const size_t mapping_size = sizes[num_sizes - 1] * 2;
6400 char* const mapping1 = (char*) ::mmap(NULL, mapping_size,
6401 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6402 -1, 0);
6403 assert(mapping1 != MAP_FAILED, "should work");
6404
6405 char* const mapping2 = (char*) ::mmap(NULL, mapping_size,
6406 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6407 -1, 0);
6408 assert(mapping2 != MAP_FAILED, "should work");
6409
6410 // Unmap the first mapping, but leave the second mapping intact: the first
6411 // mapping will serve as a value for a "good" req_addr (case 2). The second
6412 // mapping, still intact, as "bad" req_addr (case 3).
6413 ::munmap(mapping1, mapping_size);
6414
6415 // Case 1
6416 for (int i = 0; i < num_sizes; i++) {
6417 const size_t size = sizes[i];
6418 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6419 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false);
6420 if (p != NULL) {
6421 assert(is_aligned(p, alignment), "must be");
6422 small_page_write(p, size);
6423 os::Linux::release_memory_special_huge_tlbfs(p, size);
6424 }
6425 }
6426 }
6427
6428 // Case 2
6429 for (int i = 0; i < num_sizes; i++) {
6430 const size_t size = sizes[i];
6431 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6432 char* const req_addr = align_up(mapping1, alignment);
6433 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6434 if (p != NULL) {
6435 assert(p == req_addr, "must be");
6436 small_page_write(p, size);
6437 os::Linux::release_memory_special_huge_tlbfs(p, size);
6438 }
6439 }
6440 }
6441
6442 // Case 3
6443 for (int i = 0; i < num_sizes; i++) {
6444 const size_t size = sizes[i];
6445 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6446 char* const req_addr = align_up(mapping2, alignment);
6447 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6448 // as the area around req_addr contains already existing mappings, the API should always
6449 // return NULL (as per contract, it cannot return another address)
6450 assert(p == NULL, "must be");
6451 }
6452 }
6453
6454 ::munmap(mapping2, mapping_size);
6455
6456 }
6457
6458 static void test_reserve_memory_special_huge_tlbfs() {
6459 if (!UseHugeTLBFS) {
6460 return;
6461 }
6462
6463 test_reserve_memory_special_huge_tlbfs_only();
6464 test_reserve_memory_special_huge_tlbfs_mixed();
6465 }
6466
6467 static void test_reserve_memory_special_shm(size_t size, size_t alignment) {
6468 if (!UseSHM) {
6469 return;
6470 }
6471
6472 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false);
6473
6474 if (addr != NULL) {
6475 assert(is_aligned(addr, alignment), "Check");
6476 assert(is_aligned(addr, os::large_page_size()), "Check");
6477
6478 small_page_write(addr, size);
6479
6480 os::Linux::release_memory_special_shm(addr, size);
6481 }
6482 }
6483
6484 static void test_reserve_memory_special_shm() {
6485 size_t lp = os::large_page_size();
6486 size_t ag = os::vm_allocation_granularity();
6487
6488 for (size_t size = ag; size < lp * 3; size += ag) {
6489 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6490 test_reserve_memory_special_shm(size, alignment);
6491 }
6492 }
6493 }
6494
6495 static void test() {
6496 test_reserve_memory_special_huge_tlbfs();
6497 test_reserve_memory_special_shm();
6498 }
6499 };
6500
6501 void TestReserveMemorySpecial_test() {
6502 TestReserveMemorySpecial::test();
6503 }
6504
6505 #endif