1 /*
2 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 // no precompiled headers
26 #include "jvm.h"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "compiler/compileBroker.hpp"
33 #include "compiler/disassembler.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "logging/log.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "memory/filemap.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "os_linux.inline.hpp"
40 #include "os_share_linux.hpp"
41 #include "osContainer_linux.hpp"
42 #include "prims/jniFastGetField.hpp"
43 #include "prims/jvm_misc.hpp"
44 #include "runtime/arguments.hpp"
45 #include "runtime/atomic.hpp"
46 #include "runtime/extendedPC.hpp"
47 #include "runtime/globals.hpp"
48 #include "runtime/interfaceSupport.inline.hpp"
49 #include "runtime/init.hpp"
50 #include "runtime/java.hpp"
51 #include "runtime/javaCalls.hpp"
52 #include "runtime/mutexLocker.hpp"
53 #include "runtime/objectMonitor.hpp"
54 #include "runtime/orderAccess.hpp"
55 #include "runtime/osThread.hpp"
56 #include "runtime/perfMemory.hpp"
57 #include "runtime/sharedRuntime.hpp"
58 #include "runtime/statSampler.hpp"
59 #include "runtime/stubRoutines.hpp"
60 #include "runtime/thread.inline.hpp"
61 #include "runtime/threadCritical.hpp"
62 #include "runtime/threadSMR.hpp"
63 #include "runtime/timer.hpp"
64 #include "semaphore_posix.hpp"
65 #include "services/attachListener.hpp"
66 #include "services/memTracker.hpp"
67 #include "services/runtimeService.hpp"
68 #include "utilities/align.hpp"
69 #include "utilities/decoder.hpp"
70 #include "utilities/defaultStream.hpp"
71 #include "utilities/events.hpp"
72 #include "utilities/elfFile.hpp"
73 #include "utilities/growableArray.hpp"
74 #include "utilities/macros.hpp"
75 #include "utilities/vmError.hpp"
76
77 // put OS-includes here
78 # include <sys/types.h>
79 # include <sys/mman.h>
80 # include <sys/stat.h>
81 # include <sys/select.h>
82 # include <pthread.h>
83 # include <signal.h>
84 # include <errno.h>
85 # include <dlfcn.h>
86 # include <stdio.h>
87 # include <unistd.h>
88 # include <sys/resource.h>
89 # include <pthread.h>
90 # include <sys/stat.h>
91 # include <sys/time.h>
92 # include <sys/times.h>
93 # include <sys/utsname.h>
94 # include <sys/socket.h>
95 # include <sys/wait.h>
96 # include <pwd.h>
97 # include <poll.h>
98 # include <fcntl.h>
99 # include <string.h>
100 # include <syscall.h>
101 # include <sys/sysinfo.h>
102 # include <gnu/libc-version.h>
103 # include <sys/ipc.h>
104 # include <sys/shm.h>
105 # include <link.h>
106 # include <stdint.h>
107 # include <inttypes.h>
108 # include <sys/ioctl.h>
109
110 #ifndef _GNU_SOURCE
111 #define _GNU_SOURCE
112 #include <sched.h>
113 #undef _GNU_SOURCE
114 #else
115 #include <sched.h>
116 #endif
117
118 // if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling
119 // getrusage() is prepared to handle the associated failure.
120 #ifndef RUSAGE_THREAD
121 #define RUSAGE_THREAD (1) /* only the calling thread */
122 #endif
123
124 #define MAX_PATH (2 * K)
125
126 #define MAX_SECS 100000000
127
128 // for timer info max values which include all bits
129 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
130
131 #define LARGEPAGES_BIT (1 << 6)
132 #define DAX_SHARED_BIT (1 << 8)
133 ////////////////////////////////////////////////////////////////////////////////
134 // global variables
135 julong os::Linux::_physical_memory = 0;
136
137 address os::Linux::_initial_thread_stack_bottom = NULL;
138 uintptr_t os::Linux::_initial_thread_stack_size = 0;
139
140 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL;
141 int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL;
142 Mutex* os::Linux::_createThread_lock = NULL;
143 pthread_t os::Linux::_main_thread;
144 int os::Linux::_page_size = -1;
145 bool os::Linux::_supports_fast_thread_cpu_time = false;
146 uint32_t os::Linux::_os_version = 0;
147 const char * os::Linux::_glibc_version = NULL;
148 const char * os::Linux::_libpthread_version = NULL;
149
150 static jlong initial_time_count=0;
151
152 static int clock_tics_per_sec = 100;
153
154 // If the VM might have been created on the primordial thread, we need to resolve the
155 // primordial thread stack bounds and check if the current thread might be the
156 // primordial thread in places. If we know that the primordial thread is never used,
157 // such as when the VM was created by one of the standard java launchers, we can
158 // avoid this
159 static bool suppress_primordial_thread_resolution = false;
160
161 // For diagnostics to print a message once. see run_periodic_checks
162 static sigset_t check_signal_done;
163 static bool check_signals = true;
164
165 // Signal number used to suspend/resume a thread
166
167 // do not use any signal number less than SIGSEGV, see 4355769
168 static int SR_signum = SIGUSR2;
169 sigset_t SR_sigset;
170
171 // utility functions
172
173 static int SR_initialize();
174
175 julong os::available_memory() {
176 return Linux::available_memory();
177 }
178
179 julong os::Linux::available_memory() {
180 // values in struct sysinfo are "unsigned long"
181 struct sysinfo si;
182 julong avail_mem;
183
184 if (OSContainer::is_containerized()) {
185 jlong mem_limit, mem_usage;
186 if ((mem_limit = OSContainer::memory_limit_in_bytes()) < 1) {
187 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
188 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
189 }
190 if (mem_limit > 0 && (mem_usage = OSContainer::memory_usage_in_bytes()) < 1) {
191 log_debug(os, container)("container memory usage failed: " JLONG_FORMAT ", using host value", mem_usage);
192 }
193 if (mem_limit > 0 && mem_usage > 0 ) {
194 avail_mem = mem_limit > mem_usage ? (julong)mem_limit - (julong)mem_usage : 0;
195 log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem);
196 return avail_mem;
197 }
198 }
199
200 sysinfo(&si);
201 avail_mem = (julong)si.freeram * si.mem_unit;
202 log_trace(os)("available memory: " JULONG_FORMAT, avail_mem);
203 return avail_mem;
204 }
205
206 julong os::physical_memory() {
207 jlong phys_mem = 0;
208 if (OSContainer::is_containerized()) {
209 jlong mem_limit;
210 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) {
211 log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit);
212 return mem_limit;
213 }
214 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
215 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
216 }
217
218 phys_mem = Linux::physical_memory();
219 log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem);
220 return phys_mem;
221 }
222
223 // Return true if user is running as root.
224
225 bool os::have_special_privileges() {
226 static bool init = false;
227 static bool privileges = false;
228 if (!init) {
229 privileges = (getuid() != geteuid()) || (getgid() != getegid());
230 init = true;
231 }
232 return privileges;
233 }
234
235
236 #ifndef SYS_gettid
237 // i386: 224, ia64: 1105, amd64: 186, sparc 143
238 #ifdef __ia64__
239 #define SYS_gettid 1105
240 #else
241 #ifdef __i386__
242 #define SYS_gettid 224
243 #else
244 #ifdef __amd64__
245 #define SYS_gettid 186
246 #else
247 #ifdef __sparc__
248 #define SYS_gettid 143
249 #else
250 #error define gettid for the arch
251 #endif
252 #endif
253 #endif
254 #endif
255 #endif
256
257
258 // pid_t gettid()
259 //
260 // Returns the kernel thread id of the currently running thread. Kernel
261 // thread id is used to access /proc.
262 pid_t os::Linux::gettid() {
263 int rslt = syscall(SYS_gettid);
264 assert(rslt != -1, "must be."); // old linuxthreads implementation?
265 return (pid_t)rslt;
266 }
267
268 // Most versions of linux have a bug where the number of processors are
269 // determined by looking at the /proc file system. In a chroot environment,
270 // the system call returns 1.
271 static bool unsafe_chroot_detected = false;
272 static const char *unstable_chroot_error = "/proc file system not found.\n"
273 "Java may be unstable running multithreaded in a chroot "
274 "environment on Linux when /proc filesystem is not mounted.";
275
276 void os::Linux::initialize_system_info() {
277 set_processor_count(sysconf(_SC_NPROCESSORS_CONF));
278 if (processor_count() == 1) {
279 pid_t pid = os::Linux::gettid();
280 char fname[32];
281 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid);
282 FILE *fp = fopen(fname, "r");
283 if (fp == NULL) {
284 unsafe_chroot_detected = true;
285 } else {
286 fclose(fp);
287 }
288 }
289 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE);
290 assert(processor_count() > 0, "linux error");
291 }
292
293 void os::init_system_properties_values() {
294 // The next steps are taken in the product version:
295 //
296 // Obtain the JAVA_HOME value from the location of libjvm.so.
297 // This library should be located at:
298 // <JAVA_HOME>/lib/{client|server}/libjvm.so.
299 //
300 // If "/jre/lib/" appears at the right place in the path, then we
301 // assume libjvm.so is installed in a JDK and we use this path.
302 //
303 // Otherwise exit with message: "Could not create the Java virtual machine."
304 //
305 // The following extra steps are taken in the debugging version:
306 //
307 // If "/jre/lib/" does NOT appear at the right place in the path
308 // instead of exit check for $JAVA_HOME environment variable.
309 //
310 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
311 // then we append a fake suffix "hotspot/libjvm.so" to this path so
312 // it looks like libjvm.so is installed there
313 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
314 //
315 // Otherwise exit.
316 //
317 // Important note: if the location of libjvm.so changes this
318 // code needs to be changed accordingly.
319
320 // See ld(1):
321 // The linker uses the following search paths to locate required
322 // shared libraries:
323 // 1: ...
324 // ...
325 // 7: The default directories, normally /lib and /usr/lib.
326 #ifndef OVERRIDE_LIBPATH
327 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390)
328 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib"
329 #else
330 #define DEFAULT_LIBPATH "/lib:/usr/lib"
331 #endif
332 #else
333 #define DEFAULT_LIBPATH OVERRIDE_LIBPATH
334 #endif
335
336 // Base path of extensions installed on the system.
337 #define SYS_EXT_DIR "/usr/java/packages"
338 #define EXTENSIONS_DIR "/lib/ext"
339
340 // Buffer that fits several sprintfs.
341 // Note that the space for the colon and the trailing null are provided
342 // by the nulls included by the sizeof operator.
343 const size_t bufsize =
344 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
345 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
346 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
347
348 // sysclasspath, java_home, dll_dir
349 {
350 char *pslash;
351 os::jvm_path(buf, bufsize);
352
353 // Found the full path to libjvm.so.
354 // Now cut the path to <java_home>/jre if we can.
355 pslash = strrchr(buf, '/');
356 if (pslash != NULL) {
357 *pslash = '\0'; // Get rid of /libjvm.so.
358 }
359 pslash = strrchr(buf, '/');
360 if (pslash != NULL) {
361 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
362 }
363 Arguments::set_dll_dir(buf);
364
365 if (pslash != NULL) {
366 pslash = strrchr(buf, '/');
367 if (pslash != NULL) {
368 *pslash = '\0'; // Get rid of /lib.
369 }
370 }
371 Arguments::set_java_home(buf);
372 if (!set_boot_path('/', ':')) {
373 vm_exit_during_initialization("Failed setting boot class path.", NULL);
374 }
375 }
376
377 // Where to look for native libraries.
378 //
379 // Note: Due to a legacy implementation, most of the library path
380 // is set in the launcher. This was to accomodate linking restrictions
381 // on legacy Linux implementations (which are no longer supported).
382 // Eventually, all the library path setting will be done here.
383 //
384 // However, to prevent the proliferation of improperly built native
385 // libraries, the new path component /usr/java/packages is added here.
386 // Eventually, all the library path setting will be done here.
387 {
388 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
389 // should always exist (until the legacy problem cited above is
390 // addressed).
391 const char *v = ::getenv("LD_LIBRARY_PATH");
392 const char *v_colon = ":";
393 if (v == NULL) { v = ""; v_colon = ""; }
394 // That's +1 for the colon and +1 for the trailing '\0'.
395 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
396 strlen(v) + 1 +
397 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1,
398 mtInternal);
399 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon);
400 Arguments::set_library_path(ld_library_path);
401 FREE_C_HEAP_ARRAY(char, ld_library_path);
402 }
403
404 // Extensions directories.
405 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
406 Arguments::set_ext_dirs(buf);
407
408 FREE_C_HEAP_ARRAY(char, buf);
409
410 #undef DEFAULT_LIBPATH
411 #undef SYS_EXT_DIR
412 #undef EXTENSIONS_DIR
413 }
414
415 ////////////////////////////////////////////////////////////////////////////////
416 // breakpoint support
417
418 void os::breakpoint() {
419 BREAKPOINT;
420 }
421
422 extern "C" void breakpoint() {
423 // use debugger to set breakpoint here
424 }
425
426 ////////////////////////////////////////////////////////////////////////////////
427 // signal support
428
429 debug_only(static bool signal_sets_initialized = false);
430 static sigset_t unblocked_sigs, vm_sigs;
431
432 void os::Linux::signal_sets_init() {
433 // Should also have an assertion stating we are still single-threaded.
434 assert(!signal_sets_initialized, "Already initialized");
435 // Fill in signals that are necessarily unblocked for all threads in
436 // the VM. Currently, we unblock the following signals:
437 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
438 // by -Xrs (=ReduceSignalUsage));
439 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
440 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
441 // the dispositions or masks wrt these signals.
442 // Programs embedding the VM that want to use the above signals for their
443 // own purposes must, at this time, use the "-Xrs" option to prevent
444 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
445 // (See bug 4345157, and other related bugs).
446 // In reality, though, unblocking these signals is really a nop, since
447 // these signals are not blocked by default.
448 sigemptyset(&unblocked_sigs);
449 sigaddset(&unblocked_sigs, SIGILL);
450 sigaddset(&unblocked_sigs, SIGSEGV);
451 sigaddset(&unblocked_sigs, SIGBUS);
452 sigaddset(&unblocked_sigs, SIGFPE);
453 #if defined(PPC64)
454 sigaddset(&unblocked_sigs, SIGTRAP);
455 #endif
456 sigaddset(&unblocked_sigs, SR_signum);
457
458 if (!ReduceSignalUsage) {
459 if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
460 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
461 }
462 if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
463 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
464 }
465 if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
466 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
467 }
468 }
469 // Fill in signals that are blocked by all but the VM thread.
470 sigemptyset(&vm_sigs);
471 if (!ReduceSignalUsage) {
472 sigaddset(&vm_sigs, BREAK_SIGNAL);
473 }
474 debug_only(signal_sets_initialized = true);
475
476 }
477
478 // These are signals that are unblocked while a thread is running Java.
479 // (For some reason, they get blocked by default.)
480 sigset_t* os::Linux::unblocked_signals() {
481 assert(signal_sets_initialized, "Not initialized");
482 return &unblocked_sigs;
483 }
484
485 // These are the signals that are blocked while a (non-VM) thread is
486 // running Java. Only the VM thread handles these signals.
487 sigset_t* os::Linux::vm_signals() {
488 assert(signal_sets_initialized, "Not initialized");
489 return &vm_sigs;
490 }
491
492 void os::Linux::hotspot_sigmask(Thread* thread) {
493
494 //Save caller's signal mask before setting VM signal mask
495 sigset_t caller_sigmask;
496 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
497
498 OSThread* osthread = thread->osthread();
499 osthread->set_caller_sigmask(caller_sigmask);
500
501 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL);
502
503 if (!ReduceSignalUsage) {
504 if (thread->is_VM_thread()) {
505 // Only the VM thread handles BREAK_SIGNAL ...
506 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
507 } else {
508 // ... all other threads block BREAK_SIGNAL
509 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
510 }
511 }
512 }
513
514 //////////////////////////////////////////////////////////////////////////////
515 // detecting pthread library
516
517 void os::Linux::libpthread_init() {
518 // Save glibc and pthread version strings.
519 #if !defined(_CS_GNU_LIBC_VERSION) || \
520 !defined(_CS_GNU_LIBPTHREAD_VERSION)
521 #error "glibc too old (< 2.3.2)"
522 #endif
523
524 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0);
525 assert(n > 0, "cannot retrieve glibc version");
526 char *str = (char *)malloc(n, mtInternal);
527 confstr(_CS_GNU_LIBC_VERSION, str, n);
528 os::Linux::set_glibc_version(str);
529
530 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
531 assert(n > 0, "cannot retrieve pthread version");
532 str = (char *)malloc(n, mtInternal);
533 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n);
534 os::Linux::set_libpthread_version(str);
535 }
536
537 /////////////////////////////////////////////////////////////////////////////
538 // thread stack expansion
539
540 // os::Linux::manually_expand_stack() takes care of expanding the thread
541 // stack. Note that this is normally not needed: pthread stacks allocate
542 // thread stack using mmap() without MAP_NORESERVE, so the stack is already
543 // committed. Therefore it is not necessary to expand the stack manually.
544 //
545 // Manually expanding the stack was historically needed on LinuxThreads
546 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays
547 // it is kept to deal with very rare corner cases:
548 //
549 // For one, user may run the VM on an own implementation of threads
550 // whose stacks are - like the old LinuxThreads - implemented using
551 // mmap(MAP_GROWSDOWN).
552 //
553 // Also, this coding may be needed if the VM is running on the primordial
554 // thread. Normally we avoid running on the primordial thread; however,
555 // user may still invoke the VM on the primordial thread.
556 //
557 // The following historical comment describes the details about running
558 // on a thread stack allocated with mmap(MAP_GROWSDOWN):
559
560
561 // Force Linux kernel to expand current thread stack. If "bottom" is close
562 // to the stack guard, caller should block all signals.
563 //
564 // MAP_GROWSDOWN:
565 // A special mmap() flag that is used to implement thread stacks. It tells
566 // kernel that the memory region should extend downwards when needed. This
567 // allows early versions of LinuxThreads to only mmap the first few pages
568 // when creating a new thread. Linux kernel will automatically expand thread
569 // stack as needed (on page faults).
570 //
571 // However, because the memory region of a MAP_GROWSDOWN stack can grow on
572 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN
573 // region, it's hard to tell if the fault is due to a legitimate stack
574 // access or because of reading/writing non-exist memory (e.g. buffer
575 // overrun). As a rule, if the fault happens below current stack pointer,
576 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the
577 // application (see Linux kernel fault.c).
578 //
579 // This Linux feature can cause SIGSEGV when VM bangs thread stack for
580 // stack overflow detection.
581 //
582 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do
583 // not use MAP_GROWSDOWN.
584 //
585 // To get around the problem and allow stack banging on Linux, we need to
586 // manually expand thread stack after receiving the SIGSEGV.
587 //
588 // There are two ways to expand thread stack to address "bottom", we used
589 // both of them in JVM before 1.5:
590 // 1. adjust stack pointer first so that it is below "bottom", and then
591 // touch "bottom"
592 // 2. mmap() the page in question
593 //
594 // Now alternate signal stack is gone, it's harder to use 2. For instance,
595 // if current sp is already near the lower end of page 101, and we need to
596 // call mmap() to map page 100, it is possible that part of the mmap() frame
597 // will be placed in page 100. When page 100 is mapped, it is zero-filled.
598 // That will destroy the mmap() frame and cause VM to crash.
599 //
600 // The following code works by adjusting sp first, then accessing the "bottom"
601 // page to force a page fault. Linux kernel will then automatically expand the
602 // stack mapping.
603 //
604 // _expand_stack_to() assumes its frame size is less than page size, which
605 // should always be true if the function is not inlined.
606
607 static void NOINLINE _expand_stack_to(address bottom) {
608 address sp;
609 size_t size;
610 volatile char *p;
611
612 // Adjust bottom to point to the largest address within the same page, it
613 // gives us a one-page buffer if alloca() allocates slightly more memory.
614 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size());
615 bottom += os::Linux::page_size() - 1;
616
617 // sp might be slightly above current stack pointer; if that's the case, we
618 // will alloca() a little more space than necessary, which is OK. Don't use
619 // os::current_stack_pointer(), as its result can be slightly below current
620 // stack pointer, causing us to not alloca enough to reach "bottom".
621 sp = (address)&sp;
622
623 if (sp > bottom) {
624 size = sp - bottom;
625 p = (volatile char *)alloca(size);
626 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?");
627 p[0] = '\0';
628 }
629 }
630
631 void os::Linux::expand_stack_to(address bottom) {
632 _expand_stack_to(bottom);
633 }
634
635 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) {
636 assert(t!=NULL, "just checking");
637 assert(t->osthread()->expanding_stack(), "expand should be set");
638 assert(t->stack_base() != NULL, "stack_base was not initialized");
639
640 if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) {
641 sigset_t mask_all, old_sigset;
642 sigfillset(&mask_all);
643 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset);
644 _expand_stack_to(addr);
645 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL);
646 return true;
647 }
648 return false;
649 }
650
651 //////////////////////////////////////////////////////////////////////////////
652 // create new thread
653
654 // Thread start routine for all newly created threads
655 static void *thread_native_entry(Thread *thread) {
656
657 thread->record_stack_base_and_size();
658
659 // Try to randomize the cache line index of hot stack frames.
660 // This helps when threads of the same stack traces evict each other's
661 // cache lines. The threads can be either from the same JVM instance, or
662 // from different JVM instances. The benefit is especially true for
663 // processors with hyperthreading technology.
664 static int counter = 0;
665 int pid = os::current_process_id();
666 alloca(((pid ^ counter++) & 7) * 128);
667
668 thread->initialize_thread_current();
669
670 OSThread* osthread = thread->osthread();
671 Monitor* sync = osthread->startThread_lock();
672
673 osthread->set_thread_id(os::current_thread_id());
674
675 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
676 os::current_thread_id(), (uintx) pthread_self());
677
678 if (UseNUMA) {
679 int lgrp_id = os::numa_get_group_id();
680 if (lgrp_id != -1) {
681 thread->set_lgrp_id(lgrp_id);
682 }
683 }
684 // initialize signal mask for this thread
685 os::Linux::hotspot_sigmask(thread);
686
687 // initialize floating point control register
688 os::Linux::init_thread_fpu_state();
689
690 // handshaking with parent thread
691 {
692 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
693
694 // notify parent thread
695 osthread->set_state(INITIALIZED);
696 sync->notify_all();
697
698 // wait until os::start_thread()
699 while (osthread->get_state() == INITIALIZED) {
700 sync->wait(Mutex::_no_safepoint_check_flag);
701 }
702 }
703
704 // call one more level start routine
705 thread->call_run();
706
707 // Note: at this point the thread object may already have deleted itself.
708 // Prevent dereferencing it from here on out.
709 thread = NULL;
710
711 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
712 os::current_thread_id(), (uintx) pthread_self());
713
714 return 0;
715 }
716
717 bool os::create_thread(Thread* thread, ThreadType thr_type,
718 size_t req_stack_size) {
719 assert(thread->osthread() == NULL, "caller responsible");
720
721 // Allocate the OSThread object
722 OSThread* osthread = new OSThread(NULL, NULL);
723 if (osthread == NULL) {
724 return false;
725 }
726
727 // set the correct thread state
728 osthread->set_thread_type(thr_type);
729
730 // Initial state is ALLOCATED but not INITIALIZED
731 osthread->set_state(ALLOCATED);
732
733 thread->set_osthread(osthread);
734
735 // init thread attributes
736 pthread_attr_t attr;
737 pthread_attr_init(&attr);
738 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
739
740 // Calculate stack size if it's not specified by caller.
741 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
742 // In the Linux NPTL pthread implementation the guard size mechanism
743 // is not implemented properly. The posix standard requires adding
744 // the size of the guard pages to the stack size, instead Linux
745 // takes the space out of 'stacksize'. Thus we adapt the requested
746 // stack_size by the size of the guard pages to mimick proper
747 // behaviour. However, be careful not to end up with a size
748 // of zero due to overflow. Don't add the guard page in that case.
749 size_t guard_size = os::Linux::default_guard_size(thr_type);
750 if (stack_size <= SIZE_MAX - guard_size) {
751 stack_size += guard_size;
752 }
753 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned");
754
755 int status = pthread_attr_setstacksize(&attr, stack_size);
756 assert_status(status == 0, status, "pthread_attr_setstacksize");
757
758 // Configure glibc guard page.
759 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type));
760
761 ThreadState state;
762
763 {
764 pthread_t tid;
765 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
766
767 char buf[64];
768 if (ret == 0) {
769 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
770 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
771 } else {
772 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
773 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
774 }
775
776 pthread_attr_destroy(&attr);
777
778 if (ret != 0) {
779 // Need to clean up stuff we've allocated so far
780 thread->set_osthread(NULL);
781 delete osthread;
782 return false;
783 }
784
785 // Store pthread info into the OSThread
786 osthread->set_pthread_id(tid);
787
788 // Wait until child thread is either initialized or aborted
789 {
790 Monitor* sync_with_child = osthread->startThread_lock();
791 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
792 while ((state = osthread->get_state()) == ALLOCATED) {
793 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
794 }
795 }
796 }
797
798 // Aborted due to thread limit being reached
799 if (state == ZOMBIE) {
800 thread->set_osthread(NULL);
801 delete osthread;
802 return false;
803 }
804
805 // The thread is returned suspended (in state INITIALIZED),
806 // and is started higher up in the call chain
807 assert(state == INITIALIZED, "race condition");
808 return true;
809 }
810
811 /////////////////////////////////////////////////////////////////////////////
812 // attach existing thread
813
814 // bootstrap the main thread
815 bool os::create_main_thread(JavaThread* thread) {
816 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread");
817 return create_attached_thread(thread);
818 }
819
820 bool os::create_attached_thread(JavaThread* thread) {
821 #ifdef ASSERT
822 thread->verify_not_published();
823 #endif
824
825 // Allocate the OSThread object
826 OSThread* osthread = new OSThread(NULL, NULL);
827
828 if (osthread == NULL) {
829 return false;
830 }
831
832 // Store pthread info into the OSThread
833 osthread->set_thread_id(os::Linux::gettid());
834 osthread->set_pthread_id(::pthread_self());
835
836 // initialize floating point control register
837 os::Linux::init_thread_fpu_state();
838
839 // Initial thread state is RUNNABLE
840 osthread->set_state(RUNNABLE);
841
842 thread->set_osthread(osthread);
843
844 if (UseNUMA) {
845 int lgrp_id = os::numa_get_group_id();
846 if (lgrp_id != -1) {
847 thread->set_lgrp_id(lgrp_id);
848 }
849 }
850
851 if (os::is_primordial_thread()) {
852 // If current thread is primordial thread, its stack is mapped on demand,
853 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map
854 // the entire stack region to avoid SEGV in stack banging.
855 // It is also useful to get around the heap-stack-gap problem on SuSE
856 // kernel (see 4821821 for details). We first expand stack to the top
857 // of yellow zone, then enable stack yellow zone (order is significant,
858 // enabling yellow zone first will crash JVM on SuSE Linux), so there
859 // is no gap between the last two virtual memory regions.
860
861 JavaThread *jt = (JavaThread *)thread;
862 address addr = jt->stack_reserved_zone_base();
863 assert(addr != NULL, "initialization problem?");
864 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled");
865
866 osthread->set_expanding_stack();
867 os::Linux::manually_expand_stack(jt, addr);
868 osthread->clear_expanding_stack();
869 }
870
871 // initialize signal mask for this thread
872 // and save the caller's signal mask
873 os::Linux::hotspot_sigmask(thread);
874
875 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
876 os::current_thread_id(), (uintx) pthread_self());
877
878 return true;
879 }
880
881 void os::pd_start_thread(Thread* thread) {
882 OSThread * osthread = thread->osthread();
883 assert(osthread->get_state() != INITIALIZED, "just checking");
884 Monitor* sync_with_child = osthread->startThread_lock();
885 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
886 sync_with_child->notify();
887 }
888
889 // Free Linux resources related to the OSThread
890 void os::free_thread(OSThread* osthread) {
891 assert(osthread != NULL, "osthread not set");
892
893 // We are told to free resources of the argument thread,
894 // but we can only really operate on the current thread.
895 assert(Thread::current()->osthread() == osthread,
896 "os::free_thread but not current thread");
897
898 #ifdef ASSERT
899 sigset_t current;
900 sigemptyset(¤t);
901 pthread_sigmask(SIG_SETMASK, NULL, ¤t);
902 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!");
903 #endif
904
905 // Restore caller's signal mask
906 sigset_t sigmask = osthread->caller_sigmask();
907 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
908
909 delete osthread;
910 }
911
912 //////////////////////////////////////////////////////////////////////////////
913 // primordial thread
914
915 // Check if current thread is the primordial thread, similar to Solaris thr_main.
916 bool os::is_primordial_thread(void) {
917 if (suppress_primordial_thread_resolution) {
918 return false;
919 }
920 char dummy;
921 // If called before init complete, thread stack bottom will be null.
922 // Can be called if fatal error occurs before initialization.
923 if (os::Linux::initial_thread_stack_bottom() == NULL) return false;
924 assert(os::Linux::initial_thread_stack_bottom() != NULL &&
925 os::Linux::initial_thread_stack_size() != 0,
926 "os::init did not locate primordial thread's stack region");
927 if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() &&
928 (address)&dummy < os::Linux::initial_thread_stack_bottom() +
929 os::Linux::initial_thread_stack_size()) {
930 return true;
931 } else {
932 return false;
933 }
934 }
935
936 // Find the virtual memory area that contains addr
937 static bool find_vma(address addr, address* vma_low, address* vma_high) {
938 FILE *fp = fopen("/proc/self/maps", "r");
939 if (fp) {
940 address low, high;
941 while (!feof(fp)) {
942 if (fscanf(fp, "%p-%p", &low, &high) == 2) {
943 if (low <= addr && addr < high) {
944 if (vma_low) *vma_low = low;
945 if (vma_high) *vma_high = high;
946 fclose(fp);
947 return true;
948 }
949 }
950 for (;;) {
951 int ch = fgetc(fp);
952 if (ch == EOF || ch == (int)'\n') break;
953 }
954 }
955 fclose(fp);
956 }
957 return false;
958 }
959
960 // Locate primordial thread stack. This special handling of primordial thread stack
961 // is needed because pthread_getattr_np() on most (all?) Linux distros returns
962 // bogus value for the primordial process thread. While the launcher has created
963 // the VM in a new thread since JDK 6, we still have to allow for the use of the
964 // JNI invocation API from a primordial thread.
965 void os::Linux::capture_initial_stack(size_t max_size) {
966
967 // max_size is either 0 (which means accept OS default for thread stacks) or
968 // a user-specified value known to be at least the minimum needed. If we
969 // are actually on the primordial thread we can make it appear that we have a
970 // smaller max_size stack by inserting the guard pages at that location. But we
971 // cannot do anything to emulate a larger stack than what has been provided by
972 // the OS or threading library. In fact if we try to use a stack greater than
973 // what is set by rlimit then we will crash the hosting process.
974
975 // Maximum stack size is the easy part, get it from RLIMIT_STACK.
976 // If this is "unlimited" then it will be a huge value.
977 struct rlimit rlim;
978 getrlimit(RLIMIT_STACK, &rlim);
979 size_t stack_size = rlim.rlim_cur;
980
981 // 6308388: a bug in ld.so will relocate its own .data section to the
982 // lower end of primordial stack; reduce ulimit -s value a little bit
983 // so we won't install guard page on ld.so's data section.
984 // But ensure we don't underflow the stack size - allow 1 page spare
985 if (stack_size >= (size_t)(3 * page_size())) {
986 stack_size -= 2 * page_size();
987 }
988
989 // Try to figure out where the stack base (top) is. This is harder.
990 //
991 // When an application is started, glibc saves the initial stack pointer in
992 // a global variable "__libc_stack_end", which is then used by system
993 // libraries. __libc_stack_end should be pretty close to stack top. The
994 // variable is available since the very early days. However, because it is
995 // a private interface, it could disappear in the future.
996 //
997 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar
998 // to __libc_stack_end, it is very close to stack top, but isn't the real
999 // stack top. Note that /proc may not exist if VM is running as a chroot
1000 // program, so reading /proc/<pid>/stat could fail. Also the contents of
1001 // /proc/<pid>/stat could change in the future (though unlikely).
1002 //
1003 // We try __libc_stack_end first. If that doesn't work, look for
1004 // /proc/<pid>/stat. If neither of them works, we use current stack pointer
1005 // as a hint, which should work well in most cases.
1006
1007 uintptr_t stack_start;
1008
1009 // try __libc_stack_end first
1010 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end");
1011 if (p && *p) {
1012 stack_start = *p;
1013 } else {
1014 // see if we can get the start_stack field from /proc/self/stat
1015 FILE *fp;
1016 int pid;
1017 char state;
1018 int ppid;
1019 int pgrp;
1020 int session;
1021 int nr;
1022 int tpgrp;
1023 unsigned long flags;
1024 unsigned long minflt;
1025 unsigned long cminflt;
1026 unsigned long majflt;
1027 unsigned long cmajflt;
1028 unsigned long utime;
1029 unsigned long stime;
1030 long cutime;
1031 long cstime;
1032 long prio;
1033 long nice;
1034 long junk;
1035 long it_real;
1036 uintptr_t start;
1037 uintptr_t vsize;
1038 intptr_t rss;
1039 uintptr_t rsslim;
1040 uintptr_t scodes;
1041 uintptr_t ecode;
1042 int i;
1043
1044 // Figure what the primordial thread stack base is. Code is inspired
1045 // by email from Hans Boehm. /proc/self/stat begins with current pid,
1046 // followed by command name surrounded by parentheses, state, etc.
1047 char stat[2048];
1048 int statlen;
1049
1050 fp = fopen("/proc/self/stat", "r");
1051 if (fp) {
1052 statlen = fread(stat, 1, 2047, fp);
1053 stat[statlen] = '\0';
1054 fclose(fp);
1055
1056 // Skip pid and the command string. Note that we could be dealing with
1057 // weird command names, e.g. user could decide to rename java launcher
1058 // to "java 1.4.2 :)", then the stat file would look like
1059 // 1234 (java 1.4.2 :)) R ... ...
1060 // We don't really need to know the command string, just find the last
1061 // occurrence of ")" and then start parsing from there. See bug 4726580.
1062 char * s = strrchr(stat, ')');
1063
1064 i = 0;
1065 if (s) {
1066 // Skip blank chars
1067 do { s++; } while (s && isspace(*s));
1068
1069 #define _UFM UINTX_FORMAT
1070 #define _DFM INTX_FORMAT
1071
1072 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2
1073 // 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8
1074 i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM,
1075 &state, // 3 %c
1076 &ppid, // 4 %d
1077 &pgrp, // 5 %d
1078 &session, // 6 %d
1079 &nr, // 7 %d
1080 &tpgrp, // 8 %d
1081 &flags, // 9 %lu
1082 &minflt, // 10 %lu
1083 &cminflt, // 11 %lu
1084 &majflt, // 12 %lu
1085 &cmajflt, // 13 %lu
1086 &utime, // 14 %lu
1087 &stime, // 15 %lu
1088 &cutime, // 16 %ld
1089 &cstime, // 17 %ld
1090 &prio, // 18 %ld
1091 &nice, // 19 %ld
1092 &junk, // 20 %ld
1093 &it_real, // 21 %ld
1094 &start, // 22 UINTX_FORMAT
1095 &vsize, // 23 UINTX_FORMAT
1096 &rss, // 24 INTX_FORMAT
1097 &rsslim, // 25 UINTX_FORMAT
1098 &scodes, // 26 UINTX_FORMAT
1099 &ecode, // 27 UINTX_FORMAT
1100 &stack_start); // 28 UINTX_FORMAT
1101 }
1102
1103 #undef _UFM
1104 #undef _DFM
1105
1106 if (i != 28 - 2) {
1107 assert(false, "Bad conversion from /proc/self/stat");
1108 // product mode - assume we are the primordial thread, good luck in the
1109 // embedded case.
1110 warning("Can't detect primordial thread stack location - bad conversion");
1111 stack_start = (uintptr_t) &rlim;
1112 }
1113 } else {
1114 // For some reason we can't open /proc/self/stat (for example, running on
1115 // FreeBSD with a Linux emulator, or inside chroot), this should work for
1116 // most cases, so don't abort:
1117 warning("Can't detect primordial thread stack location - no /proc/self/stat");
1118 stack_start = (uintptr_t) &rlim;
1119 }
1120 }
1121
1122 // Now we have a pointer (stack_start) very close to the stack top, the
1123 // next thing to do is to figure out the exact location of stack top. We
1124 // can find out the virtual memory area that contains stack_start by
1125 // reading /proc/self/maps, it should be the last vma in /proc/self/maps,
1126 // and its upper limit is the real stack top. (again, this would fail if
1127 // running inside chroot, because /proc may not exist.)
1128
1129 uintptr_t stack_top;
1130 address low, high;
1131 if (find_vma((address)stack_start, &low, &high)) {
1132 // success, "high" is the true stack top. (ignore "low", because initial
1133 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.)
1134 stack_top = (uintptr_t)high;
1135 } else {
1136 // failed, likely because /proc/self/maps does not exist
1137 warning("Can't detect primordial thread stack location - find_vma failed");
1138 // best effort: stack_start is normally within a few pages below the real
1139 // stack top, use it as stack top, and reduce stack size so we won't put
1140 // guard page outside stack.
1141 stack_top = stack_start;
1142 stack_size -= 16 * page_size();
1143 }
1144
1145 // stack_top could be partially down the page so align it
1146 stack_top = align_up(stack_top, page_size());
1147
1148 // Allowed stack value is minimum of max_size and what we derived from rlimit
1149 if (max_size > 0) {
1150 _initial_thread_stack_size = MIN2(max_size, stack_size);
1151 } else {
1152 // Accept the rlimit max, but if stack is unlimited then it will be huge, so
1153 // clamp it at 8MB as we do on Solaris
1154 _initial_thread_stack_size = MIN2(stack_size, 8*M);
1155 }
1156 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size());
1157 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size;
1158
1159 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!");
1160
1161 if (log_is_enabled(Info, os, thread)) {
1162 // See if we seem to be on primordial process thread
1163 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) &&
1164 uintptr_t(&rlim) < stack_top;
1165
1166 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: "
1167 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT,
1168 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K,
1169 stack_top, intptr_t(_initial_thread_stack_bottom));
1170 }
1171 }
1172
1173 ////////////////////////////////////////////////////////////////////////////////
1174 // time support
1175
1176 #ifndef SUPPORTS_CLOCK_MONOTONIC
1177 #error "Build platform doesn't support clock_gettime and related functionality"
1178 #endif
1179
1180 // Time since start-up in seconds to a fine granularity.
1181 // Used by VMSelfDestructTimer and the MemProfiler.
1182 double os::elapsedTime() {
1183
1184 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
1185 }
1186
1187 jlong os::elapsed_counter() {
1188 return javaTimeNanos() - initial_time_count;
1189 }
1190
1191 jlong os::elapsed_frequency() {
1192 return NANOSECS_PER_SEC; // nanosecond resolution
1193 }
1194
1195 bool os::supports_vtime() { return true; }
1196 bool os::enable_vtime() { return false; }
1197 bool os::vtime_enabled() { return false; }
1198
1199 double os::elapsedVTime() {
1200 struct rusage usage;
1201 int retval = getrusage(RUSAGE_THREAD, &usage);
1202 if (retval == 0) {
1203 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);
1204 } else {
1205 // better than nothing, but not much
1206 return elapsedTime();
1207 }
1208 }
1209
1210 jlong os::javaTimeMillis() {
1211 timeval time;
1212 int status = gettimeofday(&time, NULL);
1213 assert(status != -1, "linux error");
1214 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
1215 }
1216
1217 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
1218 timeval time;
1219 int status = gettimeofday(&time, NULL);
1220 assert(status != -1, "linux error");
1221 seconds = jlong(time.tv_sec);
1222 nanos = jlong(time.tv_usec) * 1000;
1223 }
1224
1225 void os::Linux::fast_thread_clock_init() {
1226 if (!UseLinuxPosixThreadCPUClocks) {
1227 return;
1228 }
1229 clockid_t clockid;
1230 struct timespec tp;
1231 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) =
1232 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid");
1233
1234 // Switch to using fast clocks for thread cpu time if
1235 // the clock_getres() returns 0 error code.
1236 // Note, that some kernels may support the current thread
1237 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks
1238 // returned by the pthread_getcpuclockid().
1239 // If the fast Posix clocks are supported then the clock_getres()
1240 // must return at least tp.tv_sec == 0 which means a resolution
1241 // better than 1 sec. This is extra check for reliability.
1242
1243 if (pthread_getcpuclockid_func &&
1244 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 &&
1245 os::Posix::clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) {
1246 _supports_fast_thread_cpu_time = true;
1247 _pthread_getcpuclockid = pthread_getcpuclockid_func;
1248 }
1249 }
1250
1251 jlong os::javaTimeNanos() {
1252 if (os::supports_monotonic_clock()) {
1253 struct timespec tp;
1254 int status = os::Posix::clock_gettime(CLOCK_MONOTONIC, &tp);
1255 assert(status == 0, "gettime error");
1256 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1257 return result;
1258 } else {
1259 timeval time;
1260 int status = gettimeofday(&time, NULL);
1261 assert(status != -1, "linux error");
1262 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1263 return 1000 * usecs;
1264 }
1265 }
1266
1267 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1268 if (os::supports_monotonic_clock()) {
1269 info_ptr->max_value = ALL_64_BITS;
1270
1271 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1272 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1273 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1274 } else {
1275 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1276 info_ptr->max_value = ALL_64_BITS;
1277
1278 // gettimeofday is a real time clock so it skips
1279 info_ptr->may_skip_backward = true;
1280 info_ptr->may_skip_forward = true;
1281 }
1282
1283 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1284 }
1285
1286 // Return the real, user, and system times in seconds from an
1287 // arbitrary fixed point in the past.
1288 bool os::getTimesSecs(double* process_real_time,
1289 double* process_user_time,
1290 double* process_system_time) {
1291 struct tms ticks;
1292 clock_t real_ticks = times(&ticks);
1293
1294 if (real_ticks == (clock_t) (-1)) {
1295 return false;
1296 } else {
1297 double ticks_per_second = (double) clock_tics_per_sec;
1298 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1299 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1300 *process_real_time = ((double) real_ticks) / ticks_per_second;
1301
1302 return true;
1303 }
1304 }
1305
1306
1307 char * os::local_time_string(char *buf, size_t buflen) {
1308 struct tm t;
1309 time_t long_time;
1310 time(&long_time);
1311 localtime_r(&long_time, &t);
1312 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1313 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1314 t.tm_hour, t.tm_min, t.tm_sec);
1315 return buf;
1316 }
1317
1318 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1319 return localtime_r(clock, res);
1320 }
1321
1322 ////////////////////////////////////////////////////////////////////////////////
1323 // runtime exit support
1324
1325 // Note: os::shutdown() might be called very early during initialization, or
1326 // called from signal handler. Before adding something to os::shutdown(), make
1327 // sure it is async-safe and can handle partially initialized VM.
1328 void os::shutdown() {
1329
1330 // allow PerfMemory to attempt cleanup of any persistent resources
1331 perfMemory_exit();
1332
1333 // needs to remove object in file system
1334 AttachListener::abort();
1335
1336 // flush buffered output, finish log files
1337 ostream_abort();
1338
1339 // Check for abort hook
1340 abort_hook_t abort_hook = Arguments::abort_hook();
1341 if (abort_hook != NULL) {
1342 abort_hook();
1343 }
1344
1345 }
1346
1347 // Note: os::abort() might be called very early during initialization, or
1348 // called from signal handler. Before adding something to os::abort(), make
1349 // sure it is async-safe and can handle partially initialized VM.
1350 void os::abort(bool dump_core, void* siginfo, const void* context) {
1351 os::shutdown();
1352 if (dump_core) {
1353 #ifndef PRODUCT
1354 fdStream out(defaultStream::output_fd());
1355 out.print_raw("Current thread is ");
1356 char buf[16];
1357 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1358 out.print_raw_cr(buf);
1359 out.print_raw_cr("Dumping core ...");
1360 #endif
1361 ::abort(); // dump core
1362 }
1363
1364 ::exit(1);
1365 }
1366
1367 // Die immediately, no exit hook, no abort hook, no cleanup.
1368 void os::die() {
1369 ::abort();
1370 }
1371
1372 // thread_id is kernel thread id (similar to Solaris LWP id)
1373 intx os::current_thread_id() { return os::Linux::gettid(); }
1374 int os::current_process_id() {
1375 return ::getpid();
1376 }
1377
1378 // DLL functions
1379
1380 const char* os::dll_file_extension() { return ".so"; }
1381
1382 // This must be hard coded because it's the system's temporary
1383 // directory not the java application's temp directory, ala java.io.tmpdir.
1384 const char* os::get_temp_directory() { return "/tmp"; }
1385
1386 static bool file_exists(const char* filename) {
1387 struct stat statbuf;
1388 if (filename == NULL || strlen(filename) == 0) {
1389 return false;
1390 }
1391 return os::stat(filename, &statbuf) == 0;
1392 }
1393
1394 // check if addr is inside libjvm.so
1395 bool os::address_is_in_vm(address addr) {
1396 static address libjvm_base_addr;
1397 Dl_info dlinfo;
1398
1399 if (libjvm_base_addr == NULL) {
1400 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1401 libjvm_base_addr = (address)dlinfo.dli_fbase;
1402 }
1403 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1404 }
1405
1406 if (dladdr((void *)addr, &dlinfo) != 0) {
1407 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1408 }
1409
1410 return false;
1411 }
1412
1413 bool os::dll_address_to_function_name(address addr, char *buf,
1414 int buflen, int *offset,
1415 bool demangle) {
1416 // buf is not optional, but offset is optional
1417 assert(buf != NULL, "sanity check");
1418
1419 Dl_info dlinfo;
1420
1421 if (dladdr((void*)addr, &dlinfo) != 0) {
1422 // see if we have a matching symbol
1423 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1424 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1425 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1426 }
1427 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1428 return true;
1429 }
1430 // no matching symbol so try for just file info
1431 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1432 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1433 buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1434 return true;
1435 }
1436 }
1437 }
1438
1439 buf[0] = '\0';
1440 if (offset != NULL) *offset = -1;
1441 return false;
1442 }
1443
1444 struct _address_to_library_name {
1445 address addr; // input : memory address
1446 size_t buflen; // size of fname
1447 char* fname; // output: library name
1448 address base; // library base addr
1449 };
1450
1451 static int address_to_library_name_callback(struct dl_phdr_info *info,
1452 size_t size, void *data) {
1453 int i;
1454 bool found = false;
1455 address libbase = NULL;
1456 struct _address_to_library_name * d = (struct _address_to_library_name *)data;
1457
1458 // iterate through all loadable segments
1459 for (i = 0; i < info->dlpi_phnum; i++) {
1460 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
1461 if (info->dlpi_phdr[i].p_type == PT_LOAD) {
1462 // base address of a library is the lowest address of its loaded
1463 // segments.
1464 if (libbase == NULL || libbase > segbase) {
1465 libbase = segbase;
1466 }
1467 // see if 'addr' is within current segment
1468 if (segbase <= d->addr &&
1469 d->addr < segbase + info->dlpi_phdr[i].p_memsz) {
1470 found = true;
1471 }
1472 }
1473 }
1474
1475 // dlpi_name is NULL or empty if the ELF file is executable, return 0
1476 // so dll_address_to_library_name() can fall through to use dladdr() which
1477 // can figure out executable name from argv[0].
1478 if (found && info->dlpi_name && info->dlpi_name[0]) {
1479 d->base = libbase;
1480 if (d->fname) {
1481 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name);
1482 }
1483 return 1;
1484 }
1485 return 0;
1486 }
1487
1488 bool os::dll_address_to_library_name(address addr, char* buf,
1489 int buflen, int* offset) {
1490 // buf is not optional, but offset is optional
1491 assert(buf != NULL, "sanity check");
1492
1493 Dl_info dlinfo;
1494 struct _address_to_library_name data;
1495
1496 // There is a bug in old glibc dladdr() implementation that it could resolve
1497 // to wrong library name if the .so file has a base address != NULL. Here
1498 // we iterate through the program headers of all loaded libraries to find
1499 // out which library 'addr' really belongs to. This workaround can be
1500 // removed once the minimum requirement for glibc is moved to 2.3.x.
1501 data.addr = addr;
1502 data.fname = buf;
1503 data.buflen = buflen;
1504 data.base = NULL;
1505 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data);
1506
1507 if (rslt) {
1508 // buf already contains library name
1509 if (offset) *offset = addr - data.base;
1510 return true;
1511 }
1512 if (dladdr((void*)addr, &dlinfo) != 0) {
1513 if (dlinfo.dli_fname != NULL) {
1514 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1515 }
1516 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1517 *offset = addr - (address)dlinfo.dli_fbase;
1518 }
1519 return true;
1520 }
1521
1522 buf[0] = '\0';
1523 if (offset) *offset = -1;
1524 return false;
1525 }
1526
1527 // Loads .dll/.so and
1528 // in case of error it checks if .dll/.so was built for the
1529 // same architecture as Hotspot is running on
1530
1531
1532 // Remember the stack's state. The Linux dynamic linker will change
1533 // the stack to 'executable' at most once, so we must safepoint only once.
1534 bool os::Linux::_stack_is_executable = false;
1535
1536 // VM operation that loads a library. This is necessary if stack protection
1537 // of the Java stacks can be lost during loading the library. If we
1538 // do not stop the Java threads, they can stack overflow before the stacks
1539 // are protected again.
1540 class VM_LinuxDllLoad: public VM_Operation {
1541 private:
1542 const char *_filename;
1543 char *_ebuf;
1544 int _ebuflen;
1545 void *_lib;
1546 public:
1547 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) :
1548 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {}
1549 VMOp_Type type() const { return VMOp_LinuxDllLoad; }
1550 void doit() {
1551 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen);
1552 os::Linux::_stack_is_executable = true;
1553 }
1554 void* loaded_library() { return _lib; }
1555 };
1556
1557 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1558 void * result = NULL;
1559 bool load_attempted = false;
1560
1561 // Check whether the library to load might change execution rights
1562 // of the stack. If they are changed, the protection of the stack
1563 // guard pages will be lost. We need a safepoint to fix this.
1564 //
1565 // See Linux man page execstack(8) for more info.
1566 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) {
1567 if (!ElfFile::specifies_noexecstack(filename)) {
1568 if (!is_init_completed()) {
1569 os::Linux::_stack_is_executable = true;
1570 // This is OK - No Java threads have been created yet, and hence no
1571 // stack guard pages to fix.
1572 //
1573 // Dynamic loader will make all stacks executable after
1574 // this function returns, and will not do that again.
1575 assert(Threads::number_of_threads() == 0, "no Java threads should exist yet.");
1576 } else {
1577 warning("You have loaded library %s which might have disabled stack guard. "
1578 "The VM will try to fix the stack guard now.\n"
1579 "It's highly recommended that you fix the library with "
1580 "'execstack -c <libfile>', or link it with '-z noexecstack'.",
1581 filename);
1582
1583 assert(Thread::current()->is_Java_thread(), "must be Java thread");
1584 JavaThread *jt = JavaThread::current();
1585 if (jt->thread_state() != _thread_in_native) {
1586 // This happens when a compiler thread tries to load a hsdis-<arch>.so file
1587 // that requires ExecStack. Cannot enter safe point. Let's give up.
1588 warning("Unable to fix stack guard. Giving up.");
1589 } else {
1590 if (!LoadExecStackDllInVMThread) {
1591 // This is for the case where the DLL has an static
1592 // constructor function that executes JNI code. We cannot
1593 // load such DLLs in the VMThread.
1594 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1595 }
1596
1597 ThreadInVMfromNative tiv(jt);
1598 debug_only(VMNativeEntryWrapper vew;)
1599
1600 VM_LinuxDllLoad op(filename, ebuf, ebuflen);
1601 VMThread::execute(&op);
1602 if (LoadExecStackDllInVMThread) {
1603 result = op.loaded_library();
1604 }
1605 load_attempted = true;
1606 }
1607 }
1608 }
1609 }
1610
1611 if (!load_attempted) {
1612 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1613 }
1614
1615 if (result != NULL) {
1616 // Successful loading
1617 return result;
1618 }
1619
1620 Elf32_Ehdr elf_head;
1621 int diag_msg_max_length=ebuflen-strlen(ebuf);
1622 char* diag_msg_buf=ebuf+strlen(ebuf);
1623
1624 if (diag_msg_max_length==0) {
1625 // No more space in ebuf for additional diagnostics message
1626 return NULL;
1627 }
1628
1629
1630 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1631
1632 if (file_descriptor < 0) {
1633 // Can't open library, report dlerror() message
1634 return NULL;
1635 }
1636
1637 bool failed_to_read_elf_head=
1638 (sizeof(elf_head)!=
1639 (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1640
1641 ::close(file_descriptor);
1642 if (failed_to_read_elf_head) {
1643 // file i/o error - report dlerror() msg
1644 return NULL;
1645 }
1646
1647 typedef struct {
1648 Elf32_Half code; // Actual value as defined in elf.h
1649 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1650 unsigned char elf_class; // 32 or 64 bit
1651 unsigned char endianess; // MSB or LSB
1652 char* name; // String representation
1653 } arch_t;
1654
1655 #ifndef EM_486
1656 #define EM_486 6 /* Intel 80486 */
1657 #endif
1658 #ifndef EM_AARCH64
1659 #define EM_AARCH64 183 /* ARM AARCH64 */
1660 #endif
1661
1662 static const arch_t arch_array[]={
1663 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1664 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1665 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1666 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1667 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1668 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1669 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1670 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1671 #if defined(VM_LITTLE_ENDIAN)
1672 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"},
1673 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"},
1674 #else
1675 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1676 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"},
1677 #endif
1678 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1679 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1680 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1681 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1682 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1683 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1684 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"},
1685 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"},
1686 };
1687
1688 #if (defined IA32)
1689 static Elf32_Half running_arch_code=EM_386;
1690 #elif (defined AMD64) || (defined X32)
1691 static Elf32_Half running_arch_code=EM_X86_64;
1692 #elif (defined IA64)
1693 static Elf32_Half running_arch_code=EM_IA_64;
1694 #elif (defined __sparc) && (defined _LP64)
1695 static Elf32_Half running_arch_code=EM_SPARCV9;
1696 #elif (defined __sparc) && (!defined _LP64)
1697 static Elf32_Half running_arch_code=EM_SPARC;
1698 #elif (defined __powerpc64__)
1699 static Elf32_Half running_arch_code=EM_PPC64;
1700 #elif (defined __powerpc__)
1701 static Elf32_Half running_arch_code=EM_PPC;
1702 #elif (defined AARCH64)
1703 static Elf32_Half running_arch_code=EM_AARCH64;
1704 #elif (defined ARM)
1705 static Elf32_Half running_arch_code=EM_ARM;
1706 #elif (defined S390)
1707 static Elf32_Half running_arch_code=EM_S390;
1708 #elif (defined ALPHA)
1709 static Elf32_Half running_arch_code=EM_ALPHA;
1710 #elif (defined MIPSEL)
1711 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1712 #elif (defined PARISC)
1713 static Elf32_Half running_arch_code=EM_PARISC;
1714 #elif (defined MIPS)
1715 static Elf32_Half running_arch_code=EM_MIPS;
1716 #elif (defined M68K)
1717 static Elf32_Half running_arch_code=EM_68K;
1718 #elif (defined SH)
1719 static Elf32_Half running_arch_code=EM_SH;
1720 #else
1721 #error Method os::dll_load requires that one of following is defined:\
1722 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc
1723 #endif
1724
1725 // Identify compatability class for VM's architecture and library's architecture
1726 // Obtain string descriptions for architectures
1727
1728 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1729 int running_arch_index=-1;
1730
1731 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1732 if (running_arch_code == arch_array[i].code) {
1733 running_arch_index = i;
1734 }
1735 if (lib_arch.code == arch_array[i].code) {
1736 lib_arch.compat_class = arch_array[i].compat_class;
1737 lib_arch.name = arch_array[i].name;
1738 }
1739 }
1740
1741 assert(running_arch_index != -1,
1742 "Didn't find running architecture code (running_arch_code) in arch_array");
1743 if (running_arch_index == -1) {
1744 // Even though running architecture detection failed
1745 // we may still continue with reporting dlerror() message
1746 return NULL;
1747 }
1748
1749 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1750 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1751 return NULL;
1752 }
1753
1754 #ifndef S390
1755 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1756 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1757 return NULL;
1758 }
1759 #endif // !S390
1760
1761 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1762 if (lib_arch.name!=NULL) {
1763 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1764 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1765 lib_arch.name, arch_array[running_arch_index].name);
1766 } else {
1767 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1768 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1769 lib_arch.code,
1770 arch_array[running_arch_index].name);
1771 }
1772 }
1773
1774 return NULL;
1775 }
1776
1777 void * os::Linux::dlopen_helper(const char *filename, char *ebuf,
1778 int ebuflen) {
1779 void * result = ::dlopen(filename, RTLD_LAZY);
1780 if (result == NULL) {
1781 ::strncpy(ebuf, ::dlerror(), ebuflen - 1);
1782 ebuf[ebuflen-1] = '\0';
1783 }
1784 return result;
1785 }
1786
1787 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf,
1788 int ebuflen) {
1789 void * result = NULL;
1790 if (LoadExecStackDllInVMThread) {
1791 result = dlopen_helper(filename, ebuf, ebuflen);
1792 }
1793
1794 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a
1795 // library that requires an executable stack, or which does not have this
1796 // stack attribute set, dlopen changes the stack attribute to executable. The
1797 // read protection of the guard pages gets lost.
1798 //
1799 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad
1800 // may have been queued at the same time.
1801
1802 if (!_stack_is_executable) {
1803 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
1804 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized
1805 jt->stack_guards_enabled()) { // No pending stack overflow exceptions
1806 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) {
1807 warning("Attempt to reguard stack yellow zone failed.");
1808 }
1809 }
1810 }
1811 }
1812
1813 return result;
1814 }
1815
1816 void* os::dll_lookup(void* handle, const char* name) {
1817 void* res = dlsym(handle, name);
1818 return res;
1819 }
1820
1821 void* os::get_default_process_handle() {
1822 return (void*)::dlopen(NULL, RTLD_LAZY);
1823 }
1824
1825 static bool _print_ascii_file(const char* filename, outputStream* st, const char* hdr = NULL) {
1826 int fd = ::open(filename, O_RDONLY);
1827 if (fd == -1) {
1828 return false;
1829 }
1830
1831 if (hdr != NULL) {
1832 st->print_cr("%s", hdr);
1833 }
1834
1835 char buf[33];
1836 int bytes;
1837 buf[32] = '\0';
1838 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) {
1839 st->print_raw(buf, bytes);
1840 }
1841
1842 ::close(fd);
1843
1844 return true;
1845 }
1846
1847 void os::print_dll_info(outputStream *st) {
1848 st->print_cr("Dynamic libraries:");
1849
1850 char fname[32];
1851 pid_t pid = os::Linux::gettid();
1852
1853 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid);
1854
1855 if (!_print_ascii_file(fname, st)) {
1856 st->print("Can not get library information for pid = %d\n", pid);
1857 }
1858 }
1859
1860 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1861 FILE *procmapsFile = NULL;
1862
1863 // Open the procfs maps file for the current process
1864 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) {
1865 // Allocate PATH_MAX for file name plus a reasonable size for other fields.
1866 char line[PATH_MAX + 100];
1867
1868 // Read line by line from 'file'
1869 while (fgets(line, sizeof(line), procmapsFile) != NULL) {
1870 u8 base, top, offset, inode;
1871 char permissions[5];
1872 char device[6];
1873 char name[PATH_MAX + 1];
1874
1875 // Parse fields from line
1876 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s",
1877 &base, &top, permissions, &offset, device, &inode, name);
1878
1879 // Filter by device id '00:00' so that we only get file system mapped files.
1880 if (strcmp(device, "00:00") != 0) {
1881
1882 // Call callback with the fields of interest
1883 if(callback(name, (address)base, (address)top, param)) {
1884 // Oops abort, callback aborted
1885 fclose(procmapsFile);
1886 return 1;
1887 }
1888 }
1889 }
1890 fclose(procmapsFile);
1891 }
1892 return 0;
1893 }
1894
1895 void os::print_os_info_brief(outputStream* st) {
1896 os::Linux::print_distro_info(st);
1897
1898 os::Posix::print_uname_info(st);
1899
1900 os::Linux::print_libversion_info(st);
1901
1902 }
1903
1904 void os::print_os_info(outputStream* st) {
1905 st->print("OS:");
1906
1907 os::Linux::print_distro_info(st);
1908
1909 os::Posix::print_uname_info(st);
1910
1911 // Print warning if unsafe chroot environment detected
1912 if (unsafe_chroot_detected) {
1913 st->print("WARNING!! ");
1914 st->print_cr("%s", unstable_chroot_error);
1915 }
1916
1917 os::Linux::print_libversion_info(st);
1918
1919 os::Posix::print_rlimit_info(st);
1920
1921 os::Posix::print_load_average(st);
1922
1923 os::Linux::print_full_memory_info(st);
1924
1925 os::Linux::print_proc_sys_info(st);
1926
1927 os::Linux::print_ld_preload_file(st);
1928
1929 os::Linux::print_container_info(st);
1930 }
1931
1932 // Try to identify popular distros.
1933 // Most Linux distributions have a /etc/XXX-release file, which contains
1934 // the OS version string. Newer Linux distributions have a /etc/lsb-release
1935 // file that also contains the OS version string. Some have more than one
1936 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and
1937 // /etc/redhat-release.), so the order is important.
1938 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have
1939 // their own specific XXX-release file as well as a redhat-release file.
1940 // Because of this the XXX-release file needs to be searched for before the
1941 // redhat-release file.
1942 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the
1943 // search for redhat-release / SuSE-release needs to be before lsb-release.
1944 // Since the lsb-release file is the new standard it needs to be searched
1945 // before the older style release files.
1946 // Searching system-release (Red Hat) and os-release (other Linuxes) are a
1947 // next to last resort. The os-release file is a new standard that contains
1948 // distribution information and the system-release file seems to be an old
1949 // standard that has been replaced by the lsb-release and os-release files.
1950 // Searching for the debian_version file is the last resort. It contains
1951 // an informative string like "6.0.6" or "wheezy/sid". Because of this
1952 // "Debian " is printed before the contents of the debian_version file.
1953
1954 const char* distro_files[] = {
1955 "/etc/oracle-release",
1956 "/etc/mandriva-release",
1957 "/etc/mandrake-release",
1958 "/etc/sun-release",
1959 "/etc/redhat-release",
1960 "/etc/SuSE-release",
1961 "/etc/lsb-release",
1962 "/etc/turbolinux-release",
1963 "/etc/gentoo-release",
1964 "/etc/ltib-release",
1965 "/etc/angstrom-version",
1966 "/etc/system-release",
1967 "/etc/os-release",
1968 NULL };
1969
1970 void os::Linux::print_distro_info(outputStream* st) {
1971 for (int i = 0;; i++) {
1972 const char* file = distro_files[i];
1973 if (file == NULL) {
1974 break; // done
1975 }
1976 // If file prints, we found it.
1977 if (_print_ascii_file(file, st)) {
1978 return;
1979 }
1980 }
1981
1982 if (file_exists("/etc/debian_version")) {
1983 st->print("Debian ");
1984 _print_ascii_file("/etc/debian_version", st);
1985 } else {
1986 st->print("Linux");
1987 }
1988 st->cr();
1989 }
1990
1991 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) {
1992 char buf[256];
1993 while (fgets(buf, sizeof(buf), fp)) {
1994 // Edit out extra stuff in expected format
1995 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) {
1996 char* ptr = strstr(buf, "\""); // the name is in quotes
1997 if (ptr != NULL) {
1998 ptr++; // go beyond first quote
1999 char* nl = strchr(ptr, '\"');
2000 if (nl != NULL) *nl = '\0';
2001 strncpy(distro, ptr, length);
2002 } else {
2003 ptr = strstr(buf, "=");
2004 ptr++; // go beyond equals then
2005 char* nl = strchr(ptr, '\n');
2006 if (nl != NULL) *nl = '\0';
2007 strncpy(distro, ptr, length);
2008 }
2009 return;
2010 } else if (get_first_line) {
2011 char* nl = strchr(buf, '\n');
2012 if (nl != NULL) *nl = '\0';
2013 strncpy(distro, buf, length);
2014 return;
2015 }
2016 }
2017 // print last line and close
2018 char* nl = strchr(buf, '\n');
2019 if (nl != NULL) *nl = '\0';
2020 strncpy(distro, buf, length);
2021 }
2022
2023 static void parse_os_info(char* distro, size_t length, const char* file) {
2024 FILE* fp = fopen(file, "r");
2025 if (fp != NULL) {
2026 // if suse format, print out first line
2027 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0);
2028 parse_os_info_helper(fp, distro, length, get_first_line);
2029 fclose(fp);
2030 }
2031 }
2032
2033 void os::get_summary_os_info(char* buf, size_t buflen) {
2034 for (int i = 0;; i++) {
2035 const char* file = distro_files[i];
2036 if (file == NULL) {
2037 break; // ran out of distro_files
2038 }
2039 if (file_exists(file)) {
2040 parse_os_info(buf, buflen, file);
2041 return;
2042 }
2043 }
2044 // special case for debian
2045 if (file_exists("/etc/debian_version")) {
2046 strncpy(buf, "Debian ", buflen);
2047 if (buflen > 7) {
2048 parse_os_info(&buf[7], buflen-7, "/etc/debian_version");
2049 }
2050 } else {
2051 strncpy(buf, "Linux", buflen);
2052 }
2053 }
2054
2055 void os::Linux::print_libversion_info(outputStream* st) {
2056 // libc, pthread
2057 st->print("libc:");
2058 st->print("%s ", os::Linux::glibc_version());
2059 st->print("%s ", os::Linux::libpthread_version());
2060 st->cr();
2061 }
2062
2063 void os::Linux::print_proc_sys_info(outputStream* st) {
2064 st->cr();
2065 st->print_cr("/proc/sys/kernel/threads-max (system-wide limit on the number of threads):");
2066 _print_ascii_file("/proc/sys/kernel/threads-max", st);
2067 st->cr();
2068 st->cr();
2069
2070 st->print_cr("/proc/sys/vm/max_map_count (maximum number of memory map areas a process may have):");
2071 _print_ascii_file("/proc/sys/vm/max_map_count", st);
2072 st->cr();
2073 st->cr();
2074
2075 st->print_cr("/proc/sys/kernel/pid_max (system-wide limit on number of process identifiers):");
2076 _print_ascii_file("/proc/sys/kernel/pid_max", st);
2077 st->cr();
2078 st->cr();
2079 }
2080
2081 void os::Linux::print_full_memory_info(outputStream* st) {
2082 st->print("\n/proc/meminfo:\n");
2083 _print_ascii_file("/proc/meminfo", st);
2084 st->cr();
2085 }
2086
2087 void os::Linux::print_ld_preload_file(outputStream* st) {
2088 _print_ascii_file("/etc/ld.so.preload", st, "\n/etc/ld.so.preload:");
2089 st->cr();
2090 }
2091
2092 void os::Linux::print_container_info(outputStream* st) {
2093 if (!OSContainer::is_containerized()) {
2094 return;
2095 }
2096
2097 st->print("container (cgroup) information:\n");
2098
2099 const char *p_ct = OSContainer::container_type();
2100 st->print("container_type: %s\n", p_ct != NULL ? p_ct : "failed");
2101
2102 char *p = OSContainer::cpu_cpuset_cpus();
2103 st->print("cpu_cpuset_cpus: %s\n", p != NULL ? p : "failed");
2104 free(p);
2105
2106 p = OSContainer::cpu_cpuset_memory_nodes();
2107 st->print("cpu_memory_nodes: %s\n", p != NULL ? p : "failed");
2108 free(p);
2109
2110 int i = OSContainer::active_processor_count();
2111 if (i > 0) {
2112 st->print("active_processor_count: %d\n", i);
2113 } else {
2114 st->print("active_processor_count: failed\n");
2115 }
2116
2117 i = OSContainer::cpu_quota();
2118 st->print("cpu_quota: %d\n", i);
2119
2120 i = OSContainer::cpu_period();
2121 st->print("cpu_period: %d\n", i);
2122
2123 i = OSContainer::cpu_shares();
2124 st->print("cpu_shares: %d\n", i);
2125
2126 jlong j = OSContainer::memory_limit_in_bytes();
2127 st->print("memory_limit_in_bytes: " JLONG_FORMAT "\n", j);
2128
2129 j = OSContainer::memory_and_swap_limit_in_bytes();
2130 st->print("memory_and_swap_limit_in_bytes: " JLONG_FORMAT "\n", j);
2131
2132 j = OSContainer::memory_soft_limit_in_bytes();
2133 st->print("memory_soft_limit_in_bytes: " JLONG_FORMAT "\n", j);
2134
2135 j = OSContainer::OSContainer::memory_usage_in_bytes();
2136 st->print("memory_usage_in_bytes: " JLONG_FORMAT "\n", j);
2137
2138 j = OSContainer::OSContainer::memory_max_usage_in_bytes();
2139 st->print("memory_max_usage_in_bytes: " JLONG_FORMAT "\n", j);
2140 st->cr();
2141 }
2142
2143 void os::print_memory_info(outputStream* st) {
2144
2145 st->print("Memory:");
2146 st->print(" %dk page", os::vm_page_size()>>10);
2147
2148 // values in struct sysinfo are "unsigned long"
2149 struct sysinfo si;
2150 sysinfo(&si);
2151
2152 st->print(", physical " UINT64_FORMAT "k",
2153 os::physical_memory() >> 10);
2154 st->print("(" UINT64_FORMAT "k free)",
2155 os::available_memory() >> 10);
2156 st->print(", swap " UINT64_FORMAT "k",
2157 ((jlong)si.totalswap * si.mem_unit) >> 10);
2158 st->print("(" UINT64_FORMAT "k free)",
2159 ((jlong)si.freeswap * si.mem_unit) >> 10);
2160 st->cr();
2161 }
2162
2163 // Print the first "model name" line and the first "flags" line
2164 // that we find and nothing more. We assume "model name" comes
2165 // before "flags" so if we find a second "model name", then the
2166 // "flags" field is considered missing.
2167 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) {
2168 #if defined(IA32) || defined(AMD64)
2169 // Other platforms have less repetitive cpuinfo files
2170 FILE *fp = fopen("/proc/cpuinfo", "r");
2171 if (fp) {
2172 while (!feof(fp)) {
2173 if (fgets(buf, buflen, fp)) {
2174 // Assume model name comes before flags
2175 bool model_name_printed = false;
2176 if (strstr(buf, "model name") != NULL) {
2177 if (!model_name_printed) {
2178 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n");
2179 st->print_raw(buf);
2180 model_name_printed = true;
2181 } else {
2182 // model name printed but not flags? Odd, just return
2183 fclose(fp);
2184 return true;
2185 }
2186 }
2187 // print the flags line too
2188 if (strstr(buf, "flags") != NULL) {
2189 st->print_raw(buf);
2190 fclose(fp);
2191 return true;
2192 }
2193 }
2194 }
2195 fclose(fp);
2196 }
2197 #endif // x86 platforms
2198 return false;
2199 }
2200
2201 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
2202 // Only print the model name if the platform provides this as a summary
2203 if (!print_model_name_and_flags(st, buf, buflen)) {
2204 st->print("\n/proc/cpuinfo:\n");
2205 if (!_print_ascii_file("/proc/cpuinfo", st)) {
2206 st->print_cr(" <Not Available>");
2207 }
2208 }
2209 }
2210
2211 #if defined(AMD64) || defined(IA32) || defined(X32)
2212 const char* search_string = "model name";
2213 #elif defined(M68K)
2214 const char* search_string = "CPU";
2215 #elif defined(PPC64)
2216 const char* search_string = "cpu";
2217 #elif defined(S390)
2218 const char* search_string = "processor";
2219 #elif defined(SPARC)
2220 const char* search_string = "cpu";
2221 #else
2222 const char* search_string = "Processor";
2223 #endif
2224
2225 // Parses the cpuinfo file for string representing the model name.
2226 void os::get_summary_cpu_info(char* cpuinfo, size_t length) {
2227 FILE* fp = fopen("/proc/cpuinfo", "r");
2228 if (fp != NULL) {
2229 while (!feof(fp)) {
2230 char buf[256];
2231 if (fgets(buf, sizeof(buf), fp)) {
2232 char* start = strstr(buf, search_string);
2233 if (start != NULL) {
2234 char *ptr = start + strlen(search_string);
2235 char *end = buf + strlen(buf);
2236 while (ptr != end) {
2237 // skip whitespace and colon for the rest of the name.
2238 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') {
2239 break;
2240 }
2241 ptr++;
2242 }
2243 if (ptr != end) {
2244 // reasonable string, get rid of newline and keep the rest
2245 char* nl = strchr(buf, '\n');
2246 if (nl != NULL) *nl = '\0';
2247 strncpy(cpuinfo, ptr, length);
2248 fclose(fp);
2249 return;
2250 }
2251 }
2252 }
2253 }
2254 fclose(fp);
2255 }
2256 // cpuinfo not found or parsing failed, just print generic string. The entire
2257 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86)
2258 #if defined(AARCH64)
2259 strncpy(cpuinfo, "AArch64", length);
2260 #elif defined(AMD64)
2261 strncpy(cpuinfo, "x86_64", length);
2262 #elif defined(ARM) // Order wrt. AARCH64 is relevant!
2263 strncpy(cpuinfo, "ARM", length);
2264 #elif defined(IA32)
2265 strncpy(cpuinfo, "x86_32", length);
2266 #elif defined(IA64)
2267 strncpy(cpuinfo, "IA64", length);
2268 #elif defined(PPC)
2269 strncpy(cpuinfo, "PPC64", length);
2270 #elif defined(S390)
2271 strncpy(cpuinfo, "S390", length);
2272 #elif defined(SPARC)
2273 strncpy(cpuinfo, "sparcv9", length);
2274 #elif defined(ZERO_LIBARCH)
2275 strncpy(cpuinfo, ZERO_LIBARCH, length);
2276 #else
2277 strncpy(cpuinfo, "unknown", length);
2278 #endif
2279 }
2280
2281 static void print_signal_handler(outputStream* st, int sig,
2282 char* buf, size_t buflen);
2283
2284 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
2285 st->print_cr("Signal Handlers:");
2286 print_signal_handler(st, SIGSEGV, buf, buflen);
2287 print_signal_handler(st, SIGBUS , buf, buflen);
2288 print_signal_handler(st, SIGFPE , buf, buflen);
2289 print_signal_handler(st, SIGPIPE, buf, buflen);
2290 print_signal_handler(st, SIGXFSZ, buf, buflen);
2291 print_signal_handler(st, SIGILL , buf, buflen);
2292 print_signal_handler(st, SR_signum, buf, buflen);
2293 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
2294 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
2295 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
2296 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
2297 #if defined(PPC64)
2298 print_signal_handler(st, SIGTRAP, buf, buflen);
2299 #endif
2300 }
2301
2302 static char saved_jvm_path[MAXPATHLEN] = {0};
2303
2304 // Find the full path to the current module, libjvm.so
2305 void os::jvm_path(char *buf, jint buflen) {
2306 // Error checking.
2307 if (buflen < MAXPATHLEN) {
2308 assert(false, "must use a large-enough buffer");
2309 buf[0] = '\0';
2310 return;
2311 }
2312 // Lazy resolve the path to current module.
2313 if (saved_jvm_path[0] != 0) {
2314 strcpy(buf, saved_jvm_path);
2315 return;
2316 }
2317
2318 char dli_fname[MAXPATHLEN];
2319 bool ret = dll_address_to_library_name(
2320 CAST_FROM_FN_PTR(address, os::jvm_path),
2321 dli_fname, sizeof(dli_fname), NULL);
2322 assert(ret, "cannot locate libjvm");
2323 char *rp = NULL;
2324 if (ret && dli_fname[0] != '\0') {
2325 rp = os::Posix::realpath(dli_fname, buf, buflen);
2326 }
2327 if (rp == NULL) {
2328 return;
2329 }
2330
2331 if (Arguments::sun_java_launcher_is_altjvm()) {
2332 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
2333 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
2334 // If "/jre/lib/" appears at the right place in the string, then
2335 // assume we are installed in a JDK and we're done. Otherwise, check
2336 // for a JAVA_HOME environment variable and fix up the path so it
2337 // looks like libjvm.so is installed there (append a fake suffix
2338 // hotspot/libjvm.so).
2339 const char *p = buf + strlen(buf) - 1;
2340 for (int count = 0; p > buf && count < 5; ++count) {
2341 for (--p; p > buf && *p != '/'; --p)
2342 /* empty */ ;
2343 }
2344
2345 if (strncmp(p, "/jre/lib/", 9) != 0) {
2346 // Look for JAVA_HOME in the environment.
2347 char* java_home_var = ::getenv("JAVA_HOME");
2348 if (java_home_var != NULL && java_home_var[0] != 0) {
2349 char* jrelib_p;
2350 int len;
2351
2352 // Check the current module name "libjvm.so".
2353 p = strrchr(buf, '/');
2354 if (p == NULL) {
2355 return;
2356 }
2357 assert(strstr(p, "/libjvm") == p, "invalid library name");
2358
2359 rp = os::Posix::realpath(java_home_var, buf, buflen);
2360 if (rp == NULL) {
2361 return;
2362 }
2363
2364 // determine if this is a legacy image or modules image
2365 // modules image doesn't have "jre" subdirectory
2366 len = strlen(buf);
2367 assert(len < buflen, "Ran out of buffer room");
2368 jrelib_p = buf + len;
2369 snprintf(jrelib_p, buflen-len, "/jre/lib");
2370 if (0 != access(buf, F_OK)) {
2371 snprintf(jrelib_p, buflen-len, "/lib");
2372 }
2373
2374 if (0 == access(buf, F_OK)) {
2375 // Use current module name "libjvm.so"
2376 len = strlen(buf);
2377 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
2378 } else {
2379 // Go back to path of .so
2380 rp = os::Posix::realpath(dli_fname, buf, buflen);
2381 if (rp == NULL) {
2382 return;
2383 }
2384 }
2385 }
2386 }
2387 }
2388
2389 strncpy(saved_jvm_path, buf, MAXPATHLEN);
2390 saved_jvm_path[MAXPATHLEN - 1] = '\0';
2391 }
2392
2393 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
2394 // no prefix required, not even "_"
2395 }
2396
2397 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
2398 // no suffix required
2399 }
2400
2401 ////////////////////////////////////////////////////////////////////////////////
2402 // sun.misc.Signal support
2403
2404 static volatile jint sigint_count = 0;
2405
2406 static void UserHandler(int sig, void *siginfo, void *context) {
2407 // 4511530 - sem_post is serialized and handled by the manager thread. When
2408 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
2409 // don't want to flood the manager thread with sem_post requests.
2410 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
2411 return;
2412 }
2413
2414 // Ctrl-C is pressed during error reporting, likely because the error
2415 // handler fails to abort. Let VM die immediately.
2416 if (sig == SIGINT && VMError::is_error_reported()) {
2417 os::die();
2418 }
2419
2420 os::signal_notify(sig);
2421 }
2422
2423 void* os::user_handler() {
2424 return CAST_FROM_FN_PTR(void*, UserHandler);
2425 }
2426
2427 static struct timespec create_semaphore_timespec(unsigned int sec, int nsec) {
2428 struct timespec ts;
2429 // Semaphore's are always associated with CLOCK_REALTIME
2430 os::Posix::clock_gettime(CLOCK_REALTIME, &ts);
2431 // see os_posix.cpp for discussion on overflow checking
2432 if (sec >= MAX_SECS) {
2433 ts.tv_sec += MAX_SECS;
2434 ts.tv_nsec = 0;
2435 } else {
2436 ts.tv_sec += sec;
2437 ts.tv_nsec += nsec;
2438 if (ts.tv_nsec >= NANOSECS_PER_SEC) {
2439 ts.tv_nsec -= NANOSECS_PER_SEC;
2440 ++ts.tv_sec; // note: this must be <= max_secs
2441 }
2442 }
2443
2444 return ts;
2445 }
2446
2447 extern "C" {
2448 typedef void (*sa_handler_t)(int);
2449 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
2450 }
2451
2452 void* os::signal(int signal_number, void* handler) {
2453 struct sigaction sigAct, oldSigAct;
2454
2455 sigfillset(&(sigAct.sa_mask));
2456 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
2457 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
2458
2459 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
2460 // -1 means registration failed
2461 return (void *)-1;
2462 }
2463
2464 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
2465 }
2466
2467 void os::signal_raise(int signal_number) {
2468 ::raise(signal_number);
2469 }
2470
2471 // The following code is moved from os.cpp for making this
2472 // code platform specific, which it is by its very nature.
2473
2474 // Will be modified when max signal is changed to be dynamic
2475 int os::sigexitnum_pd() {
2476 return NSIG;
2477 }
2478
2479 // a counter for each possible signal value
2480 static volatile jint pending_signals[NSIG+1] = { 0 };
2481
2482 // Linux(POSIX) specific hand shaking semaphore.
2483 static Semaphore* sig_sem = NULL;
2484 static PosixSemaphore sr_semaphore;
2485
2486 static void jdk_misc_signal_init() {
2487 // Initialize signal structures
2488 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2489
2490 // Initialize signal semaphore
2491 sig_sem = new Semaphore();
2492 }
2493
2494 void os::signal_notify(int sig) {
2495 if (sig_sem != NULL) {
2496 Atomic::inc(&pending_signals[sig]);
2497 sig_sem->signal();
2498 } else {
2499 // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
2500 // initialization isn't called.
2501 assert(ReduceSignalUsage, "signal semaphore should be created");
2502 }
2503 }
2504
2505 static int check_pending_signals() {
2506 Atomic::store(0, &sigint_count);
2507 for (;;) {
2508 for (int i = 0; i < NSIG + 1; i++) {
2509 jint n = pending_signals[i];
2510 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2511 return i;
2512 }
2513 }
2514 JavaThread *thread = JavaThread::current();
2515 ThreadBlockInVM tbivm(thread);
2516
2517 bool threadIsSuspended;
2518 do {
2519 thread->set_suspend_equivalent();
2520 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2521 sig_sem->wait();
2522
2523 // were we externally suspended while we were waiting?
2524 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2525 if (threadIsSuspended) {
2526 // The semaphore has been incremented, but while we were waiting
2527 // another thread suspended us. We don't want to continue running
2528 // while suspended because that would surprise the thread that
2529 // suspended us.
2530 sig_sem->signal();
2531
2532 thread->java_suspend_self();
2533 }
2534 } while (threadIsSuspended);
2535 }
2536 }
2537
2538 int os::signal_wait() {
2539 return check_pending_signals();
2540 }
2541
2542 ////////////////////////////////////////////////////////////////////////////////
2543 // Virtual Memory
2544
2545 int os::vm_page_size() {
2546 // Seems redundant as all get out
2547 assert(os::Linux::page_size() != -1, "must call os::init");
2548 return os::Linux::page_size();
2549 }
2550
2551 // Solaris allocates memory by pages.
2552 int os::vm_allocation_granularity() {
2553 assert(os::Linux::page_size() != -1, "must call os::init");
2554 return os::Linux::page_size();
2555 }
2556
2557 // Rationale behind this function:
2558 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2559 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2560 // samples for JITted code. Here we create private executable mapping over the code cache
2561 // and then we can use standard (well, almost, as mapping can change) way to provide
2562 // info for the reporting script by storing timestamp and location of symbol
2563 void linux_wrap_code(char* base, size_t size) {
2564 static volatile jint cnt = 0;
2565
2566 if (!UseOprofile) {
2567 return;
2568 }
2569
2570 char buf[PATH_MAX+1];
2571 int num = Atomic::add(1, &cnt);
2572
2573 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d",
2574 os::get_temp_directory(), os::current_process_id(), num);
2575 unlink(buf);
2576
2577 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2578
2579 if (fd != -1) {
2580 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2581 if (rv != (off_t)-1) {
2582 if (::write(fd, "", 1) == 1) {
2583 mmap(base, size,
2584 PROT_READ|PROT_WRITE|PROT_EXEC,
2585 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2586 }
2587 }
2588 ::close(fd);
2589 unlink(buf);
2590 }
2591 }
2592
2593 static bool recoverable_mmap_error(int err) {
2594 // See if the error is one we can let the caller handle. This
2595 // list of errno values comes from JBS-6843484. I can't find a
2596 // Linux man page that documents this specific set of errno
2597 // values so while this list currently matches Solaris, it may
2598 // change as we gain experience with this failure mode.
2599 switch (err) {
2600 case EBADF:
2601 case EINVAL:
2602 case ENOTSUP:
2603 // let the caller deal with these errors
2604 return true;
2605
2606 default:
2607 // Any remaining errors on this OS can cause our reserved mapping
2608 // to be lost. That can cause confusion where different data
2609 // structures think they have the same memory mapped. The worst
2610 // scenario is if both the VM and a library think they have the
2611 // same memory mapped.
2612 return false;
2613 }
2614 }
2615
2616 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2617 int err) {
2618 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2619 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
2620 os::strerror(err), err);
2621 }
2622
2623 static void warn_fail_commit_memory(char* addr, size_t size,
2624 size_t alignment_hint, bool exec,
2625 int err) {
2626 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2627 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size,
2628 alignment_hint, exec, os::strerror(err), err);
2629 }
2630
2631 // NOTE: Linux kernel does not really reserve the pages for us.
2632 // All it does is to check if there are enough free pages
2633 // left at the time of mmap(). This could be a potential
2634 // problem.
2635 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) {
2636 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2637 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2638 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2639 if (res != (uintptr_t) MAP_FAILED) {
2640 if (UseNUMAInterleaving) {
2641 numa_make_global(addr, size);
2642 }
2643 return 0;
2644 }
2645
2646 int err = errno; // save errno from mmap() call above
2647
2648 if (!recoverable_mmap_error(err)) {
2649 warn_fail_commit_memory(addr, size, exec, err);
2650 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory.");
2651 }
2652
2653 return err;
2654 }
2655
2656 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2657 return os::Linux::commit_memory_impl(addr, size, exec) == 0;
2658 }
2659
2660 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2661 const char* mesg) {
2662 assert(mesg != NULL, "mesg must be specified");
2663 int err = os::Linux::commit_memory_impl(addr, size, exec);
2664 if (err != 0) {
2665 // the caller wants all commit errors to exit with the specified mesg:
2666 warn_fail_commit_memory(addr, size, exec, err);
2667 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2668 }
2669 }
2670
2671 // Define MAP_HUGETLB here so we can build HotSpot on old systems.
2672 #ifndef MAP_HUGETLB
2673 #define MAP_HUGETLB 0x40000
2674 #endif
2675
2676 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems.
2677 #ifndef MADV_HUGEPAGE
2678 #define MADV_HUGEPAGE 14
2679 #endif
2680
2681 int os::Linux::commit_memory_impl(char* addr, size_t size,
2682 size_t alignment_hint, bool exec) {
2683 int err = os::Linux::commit_memory_impl(addr, size, exec);
2684 if (err == 0) {
2685 realign_memory(addr, size, alignment_hint);
2686 }
2687 return err;
2688 }
2689
2690 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2691 bool exec) {
2692 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0;
2693 }
2694
2695 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2696 size_t alignment_hint, bool exec,
2697 const char* mesg) {
2698 assert(mesg != NULL, "mesg must be specified");
2699 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec);
2700 if (err != 0) {
2701 // the caller wants all commit errors to exit with the specified mesg:
2702 warn_fail_commit_memory(addr, size, alignment_hint, exec, err);
2703 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2704 }
2705 }
2706
2707 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2708 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) {
2709 // We don't check the return value: madvise(MADV_HUGEPAGE) may not
2710 // be supported or the memory may already be backed by huge pages.
2711 ::madvise(addr, bytes, MADV_HUGEPAGE);
2712 }
2713 }
2714
2715 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2716 // This method works by doing an mmap over an existing mmaping and effectively discarding
2717 // the existing pages. However it won't work for SHM-based large pages that cannot be
2718 // uncommitted at all. We don't do anything in this case to avoid creating a segment with
2719 // small pages on top of the SHM segment. This method always works for small pages, so we
2720 // allow that in any case.
2721 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) {
2722 commit_memory(addr, bytes, alignment_hint, !ExecMem);
2723 }
2724 }
2725
2726 void os::numa_make_global(char *addr, size_t bytes) {
2727 Linux::numa_interleave_memory(addr, bytes);
2728 }
2729
2730 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the
2731 // bind policy to MPOL_PREFERRED for the current thread.
2732 #define USE_MPOL_PREFERRED 0
2733
2734 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2735 // To make NUMA and large pages more robust when both enabled, we need to ease
2736 // the requirements on where the memory should be allocated. MPOL_BIND is the
2737 // default policy and it will force memory to be allocated on the specified
2738 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on
2739 // the specified node, but will not force it. Using this policy will prevent
2740 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no
2741 // free large pages.
2742 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED);
2743 Linux::numa_tonode_memory(addr, bytes, lgrp_hint);
2744 }
2745
2746 bool os::numa_topology_changed() { return false; }
2747
2748 size_t os::numa_get_groups_num() {
2749 // Return just the number of nodes in which it's possible to allocate memory
2750 // (in numa terminology, configured nodes).
2751 return Linux::numa_num_configured_nodes();
2752 }
2753
2754 int os::numa_get_group_id() {
2755 int cpu_id = Linux::sched_getcpu();
2756 if (cpu_id != -1) {
2757 int lgrp_id = Linux::get_node_by_cpu(cpu_id);
2758 if (lgrp_id != -1) {
2759 return lgrp_id;
2760 }
2761 }
2762 return 0;
2763 }
2764
2765 int os::Linux::get_existing_num_nodes() {
2766 int node;
2767 int highest_node_number = Linux::numa_max_node();
2768 int num_nodes = 0;
2769
2770 // Get the total number of nodes in the system including nodes without memory.
2771 for (node = 0; node <= highest_node_number; node++) {
2772 if (isnode_in_existing_nodes(node)) {
2773 num_nodes++;
2774 }
2775 }
2776 return num_nodes;
2777 }
2778
2779 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2780 int highest_node_number = Linux::numa_max_node();
2781 size_t i = 0;
2782
2783 // Map all node ids in which it is possible to allocate memory. Also nodes are
2784 // not always consecutively available, i.e. available from 0 to the highest
2785 // node number. If the nodes have been bound explicitly using numactl membind,
2786 // then allocate memory from those nodes only.
2787 for (int node = 0; node <= highest_node_number; node++) {
2788 if (Linux::isnode_in_bound_nodes((unsigned int)node)) {
2789 ids[i++] = node;
2790 }
2791 }
2792 return i;
2793 }
2794
2795 bool os::get_page_info(char *start, page_info* info) {
2796 return false;
2797 }
2798
2799 char *os::scan_pages(char *start, char* end, page_info* page_expected,
2800 page_info* page_found) {
2801 return end;
2802 }
2803
2804
2805 int os::Linux::sched_getcpu_syscall(void) {
2806 unsigned int cpu = 0;
2807 int retval = -1;
2808
2809 #if defined(IA32)
2810 #ifndef SYS_getcpu
2811 #define SYS_getcpu 318
2812 #endif
2813 retval = syscall(SYS_getcpu, &cpu, NULL, NULL);
2814 #elif defined(AMD64)
2815 // Unfortunately we have to bring all these macros here from vsyscall.h
2816 // to be able to compile on old linuxes.
2817 #define __NR_vgetcpu 2
2818 #define VSYSCALL_START (-10UL << 20)
2819 #define VSYSCALL_SIZE 1024
2820 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
2821 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache);
2822 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu);
2823 retval = vgetcpu(&cpu, NULL, NULL);
2824 #endif
2825
2826 return (retval == -1) ? retval : cpu;
2827 }
2828
2829 void os::Linux::sched_getcpu_init() {
2830 // sched_getcpu() should be in libc.
2831 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
2832 dlsym(RTLD_DEFAULT, "sched_getcpu")));
2833
2834 // If it's not, try a direct syscall.
2835 if (sched_getcpu() == -1) {
2836 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
2837 (void*)&sched_getcpu_syscall));
2838 }
2839
2840 if (sched_getcpu() == -1) {
2841 vm_exit_during_initialization("getcpu(2) system call not supported by kernel");
2842 }
2843 }
2844
2845 // Something to do with the numa-aware allocator needs these symbols
2846 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { }
2847 extern "C" JNIEXPORT void numa_error(char *where) { }
2848
2849 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails
2850 // load symbol from base version instead.
2851 void* os::Linux::libnuma_dlsym(void* handle, const char *name) {
2852 void *f = dlvsym(handle, name, "libnuma_1.1");
2853 if (f == NULL) {
2854 f = dlsym(handle, name);
2855 }
2856 return f;
2857 }
2858
2859 // Handle request to load libnuma symbol version 1.2 (API v2) only.
2860 // Return NULL if the symbol is not defined in this particular version.
2861 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) {
2862 return dlvsym(handle, name, "libnuma_1.2");
2863 }
2864
2865 bool os::Linux::libnuma_init() {
2866 if (sched_getcpu() != -1) { // Requires sched_getcpu() support
2867 void *handle = dlopen("libnuma.so.1", RTLD_LAZY);
2868 if (handle != NULL) {
2869 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t,
2870 libnuma_dlsym(handle, "numa_node_to_cpus")));
2871 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t,
2872 libnuma_dlsym(handle, "numa_max_node")));
2873 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t,
2874 libnuma_dlsym(handle, "numa_num_configured_nodes")));
2875 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t,
2876 libnuma_dlsym(handle, "numa_available")));
2877 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t,
2878 libnuma_dlsym(handle, "numa_tonode_memory")));
2879 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t,
2880 libnuma_dlsym(handle, "numa_interleave_memory")));
2881 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t,
2882 libnuma_v2_dlsym(handle, "numa_interleave_memory")));
2883 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t,
2884 libnuma_dlsym(handle, "numa_set_bind_policy")));
2885 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t,
2886 libnuma_dlsym(handle, "numa_bitmask_isbitset")));
2887 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t,
2888 libnuma_dlsym(handle, "numa_distance")));
2889 set_numa_get_membind(CAST_TO_FN_PTR(numa_get_membind_func_t,
2890 libnuma_v2_dlsym(handle, "numa_get_membind")));
2891
2892 if (numa_available() != -1) {
2893 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes"));
2894 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr"));
2895 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr"));
2896 // Create an index -> node mapping, since nodes are not always consecutive
2897 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
2898 rebuild_nindex_to_node_map();
2899 // Create a cpu -> node mapping
2900 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
2901 rebuild_cpu_to_node_map();
2902 return true;
2903 }
2904 }
2905 }
2906 return false;
2907 }
2908
2909 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
2910 // Creating guard page is very expensive. Java thread has HotSpot
2911 // guard pages, only enable glibc guard page for non-Java threads.
2912 // (Remember: compiler thread is a Java thread, too!)
2913 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size());
2914 }
2915
2916 void os::Linux::rebuild_nindex_to_node_map() {
2917 int highest_node_number = Linux::numa_max_node();
2918
2919 nindex_to_node()->clear();
2920 for (int node = 0; node <= highest_node_number; node++) {
2921 if (Linux::isnode_in_existing_nodes(node)) {
2922 nindex_to_node()->append(node);
2923 }
2924 }
2925 }
2926
2927 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id.
2928 // The table is later used in get_node_by_cpu().
2929 void os::Linux::rebuild_cpu_to_node_map() {
2930 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure
2931 // in libnuma (possible values are starting from 16,
2932 // and continuing up with every other power of 2, but less
2933 // than the maximum number of CPUs supported by kernel), and
2934 // is a subject to change (in libnuma version 2 the requirements
2935 // are more reasonable) we'll just hardcode the number they use
2936 // in the library.
2937 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT;
2938
2939 size_t cpu_num = processor_count();
2940 size_t cpu_map_size = NCPUS / BitsPerCLong;
2941 size_t cpu_map_valid_size =
2942 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size);
2943
2944 cpu_to_node()->clear();
2945 cpu_to_node()->at_grow(cpu_num - 1);
2946
2947 size_t node_num = get_existing_num_nodes();
2948
2949 int distance = 0;
2950 int closest_distance = INT_MAX;
2951 int closest_node = 0;
2952 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal);
2953 for (size_t i = 0; i < node_num; i++) {
2954 // Check if node is configured (not a memory-less node). If it is not, find
2955 // the closest configured node. Check also if node is bound, i.e. it's allowed
2956 // to allocate memory from the node. If it's not allowed, map cpus in that node
2957 // to the closest node from which memory allocation is allowed.
2958 if (!isnode_in_configured_nodes(nindex_to_node()->at(i)) ||
2959 !isnode_in_bound_nodes(nindex_to_node()->at(i))) {
2960 closest_distance = INT_MAX;
2961 // Check distance from all remaining nodes in the system. Ignore distance
2962 // from itself, from another non-configured node, and from another non-bound
2963 // node.
2964 for (size_t m = 0; m < node_num; m++) {
2965 if (m != i &&
2966 isnode_in_configured_nodes(nindex_to_node()->at(m)) &&
2967 isnode_in_bound_nodes(nindex_to_node()->at(m))) {
2968 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m));
2969 // If a closest node is found, update. There is always at least one
2970 // configured and bound node in the system so there is always at least
2971 // one node close.
2972 if (distance != 0 && distance < closest_distance) {
2973 closest_distance = distance;
2974 closest_node = nindex_to_node()->at(m);
2975 }
2976 }
2977 }
2978 } else {
2979 // Current node is already a configured node.
2980 closest_node = nindex_to_node()->at(i);
2981 }
2982
2983 // Get cpus from the original node and map them to the closest node. If node
2984 // is a configured node (not a memory-less node), then original node and
2985 // closest node are the same.
2986 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) {
2987 for (size_t j = 0; j < cpu_map_valid_size; j++) {
2988 if (cpu_map[j] != 0) {
2989 for (size_t k = 0; k < BitsPerCLong; k++) {
2990 if (cpu_map[j] & (1UL << k)) {
2991 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node);
2992 }
2993 }
2994 }
2995 }
2996 }
2997 }
2998 FREE_C_HEAP_ARRAY(unsigned long, cpu_map);
2999 }
3000
3001 int os::Linux::get_node_by_cpu(int cpu_id) {
3002 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) {
3003 return cpu_to_node()->at(cpu_id);
3004 }
3005 return -1;
3006 }
3007
3008 GrowableArray<int>* os::Linux::_cpu_to_node;
3009 GrowableArray<int>* os::Linux::_nindex_to_node;
3010 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu;
3011 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus;
3012 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node;
3013 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes;
3014 os::Linux::numa_available_func_t os::Linux::_numa_available;
3015 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory;
3016 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory;
3017 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2;
3018 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy;
3019 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset;
3020 os::Linux::numa_distance_func_t os::Linux::_numa_distance;
3021 os::Linux::numa_get_membind_func_t os::Linux::_numa_get_membind;
3022 unsigned long* os::Linux::_numa_all_nodes;
3023 struct bitmask* os::Linux::_numa_all_nodes_ptr;
3024 struct bitmask* os::Linux::_numa_nodes_ptr;
3025
3026 bool os::pd_uncommit_memory(char* addr, size_t size) {
3027 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
3028 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
3029 return res != (uintptr_t) MAP_FAILED;
3030 }
3031
3032 static address get_stack_commited_bottom(address bottom, size_t size) {
3033 address nbot = bottom;
3034 address ntop = bottom + size;
3035
3036 size_t page_sz = os::vm_page_size();
3037 unsigned pages = size / page_sz;
3038
3039 unsigned char vec[1];
3040 unsigned imin = 1, imax = pages + 1, imid;
3041 int mincore_return_value = 0;
3042
3043 assert(imin <= imax, "Unexpected page size");
3044
3045 while (imin < imax) {
3046 imid = (imax + imin) / 2;
3047 nbot = ntop - (imid * page_sz);
3048
3049 // Use a trick with mincore to check whether the page is mapped or not.
3050 // mincore sets vec to 1 if page resides in memory and to 0 if page
3051 // is swapped output but if page we are asking for is unmapped
3052 // it returns -1,ENOMEM
3053 mincore_return_value = mincore(nbot, page_sz, vec);
3054
3055 if (mincore_return_value == -1) {
3056 // Page is not mapped go up
3057 // to find first mapped page
3058 if (errno != EAGAIN) {
3059 assert(errno == ENOMEM, "Unexpected mincore errno");
3060 imax = imid;
3061 }
3062 } else {
3063 // Page is mapped go down
3064 // to find first not mapped page
3065 imin = imid + 1;
3066 }
3067 }
3068
3069 nbot = nbot + page_sz;
3070
3071 // Adjust stack bottom one page up if last checked page is not mapped
3072 if (mincore_return_value == -1) {
3073 nbot = nbot + page_sz;
3074 }
3075
3076 return nbot;
3077 }
3078
3079 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
3080 int mincore_return_value;
3081 const size_t stripe = 1024; // query this many pages each time
3082 unsigned char vec[stripe + 1];
3083 // set a guard
3084 vec[stripe] = 'X';
3085
3086 const size_t page_sz = os::vm_page_size();
3087 size_t pages = size / page_sz;
3088
3089 assert(is_aligned(start, page_sz), "Start address must be page aligned");
3090 assert(is_aligned(size, page_sz), "Size must be page aligned");
3091
3092 committed_start = NULL;
3093
3094 int loops = (pages + stripe - 1) / stripe;
3095 int committed_pages = 0;
3096 address loop_base = start;
3097 bool found_range = false;
3098
3099 for (int index = 0; index < loops && !found_range; index ++) {
3100 assert(pages > 0, "Nothing to do");
3101 int pages_to_query = (pages >= stripe) ? stripe : pages;
3102 pages -= pages_to_query;
3103
3104 // Get stable read
3105 while ((mincore_return_value = mincore(loop_base, pages_to_query * page_sz, vec)) == -1 && errno == EAGAIN);
3106
3107 // During shutdown, some memory goes away without properly notifying NMT,
3108 // E.g. ConcurrentGCThread/WatcherThread can exit without deleting thread object.
3109 // Bailout and return as not committed for now.
3110 if (mincore_return_value == -1 && errno == ENOMEM) {
3111 return false;
3112 }
3113
3114 assert(vec[stripe] == 'X', "overflow guard");
3115 assert(mincore_return_value == 0, "Range must be valid");
3116 // Process this stripe
3117 for (int vecIdx = 0; vecIdx < pages_to_query; vecIdx ++) {
3118 if ((vec[vecIdx] & 0x01) == 0) { // not committed
3119 // End of current contiguous region
3120 if (committed_start != NULL) {
3121 found_range = true;
3122 break;
3123 }
3124 } else { // committed
3125 // Start of region
3126 if (committed_start == NULL) {
3127 committed_start = loop_base + page_sz * vecIdx;
3128 }
3129 committed_pages ++;
3130 }
3131 }
3132
3133 loop_base += pages_to_query * page_sz;
3134 }
3135
3136 if (committed_start != NULL) {
3137 assert(committed_pages > 0, "Must have committed region");
3138 assert(committed_pages <= int(size / page_sz), "Can not commit more than it has");
3139 assert(committed_start >= start && committed_start < start + size, "Out of range");
3140 committed_size = page_sz * committed_pages;
3141 return true;
3142 } else {
3143 assert(committed_pages == 0, "Should not have committed region");
3144 return false;
3145 }
3146 }
3147
3148
3149 // Linux uses a growable mapping for the stack, and if the mapping for
3150 // the stack guard pages is not removed when we detach a thread the
3151 // stack cannot grow beyond the pages where the stack guard was
3152 // mapped. If at some point later in the process the stack expands to
3153 // that point, the Linux kernel cannot expand the stack any further
3154 // because the guard pages are in the way, and a segfault occurs.
3155 //
3156 // However, it's essential not to split the stack region by unmapping
3157 // a region (leaving a hole) that's already part of the stack mapping,
3158 // so if the stack mapping has already grown beyond the guard pages at
3159 // the time we create them, we have to truncate the stack mapping.
3160 // So, we need to know the extent of the stack mapping when
3161 // create_stack_guard_pages() is called.
3162
3163 // We only need this for stacks that are growable: at the time of
3164 // writing thread stacks don't use growable mappings (i.e. those
3165 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this
3166 // only applies to the main thread.
3167
3168 // If the (growable) stack mapping already extends beyond the point
3169 // where we're going to put our guard pages, truncate the mapping at
3170 // that point by munmap()ping it. This ensures that when we later
3171 // munmap() the guard pages we don't leave a hole in the stack
3172 // mapping. This only affects the main/primordial thread
3173
3174 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
3175 if (os::is_primordial_thread()) {
3176 // As we manually grow stack up to bottom inside create_attached_thread(),
3177 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and
3178 // we don't need to do anything special.
3179 // Check it first, before calling heavy function.
3180 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom();
3181 unsigned char vec[1];
3182
3183 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) {
3184 // Fallback to slow path on all errors, including EAGAIN
3185 stack_extent = (uintptr_t) get_stack_commited_bottom(
3186 os::Linux::initial_thread_stack_bottom(),
3187 (size_t)addr - stack_extent);
3188 }
3189
3190 if (stack_extent < (uintptr_t)addr) {
3191 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent));
3192 }
3193 }
3194
3195 return os::commit_memory(addr, size, !ExecMem);
3196 }
3197
3198 // If this is a growable mapping, remove the guard pages entirely by
3199 // munmap()ping them. If not, just call uncommit_memory(). This only
3200 // affects the main/primordial thread, but guard against future OS changes.
3201 // It's safe to always unmap guard pages for primordial thread because we
3202 // always place it right after end of the mapped region.
3203
3204 bool os::remove_stack_guard_pages(char* addr, size_t size) {
3205 uintptr_t stack_extent, stack_base;
3206
3207 if (os::is_primordial_thread()) {
3208 return ::munmap(addr, size) == 0;
3209 }
3210
3211 return os::uncommit_memory(addr, size);
3212 }
3213
3214 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
3215 // at 'requested_addr'. If there are existing memory mappings at the same
3216 // location, however, they will be overwritten. If 'fixed' is false,
3217 // 'requested_addr' is only treated as a hint, the return value may or
3218 // may not start from the requested address. Unlike Linux mmap(), this
3219 // function returns NULL to indicate failure.
3220 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
3221 char * addr;
3222 int flags;
3223
3224 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
3225 if (fixed) {
3226 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address");
3227 flags |= MAP_FIXED;
3228 }
3229
3230 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
3231 // touch an uncommitted page. Otherwise, the read/write might
3232 // succeed if we have enough swap space to back the physical page.
3233 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
3234 flags, -1, 0);
3235
3236 return addr == MAP_FAILED ? NULL : addr;
3237 }
3238
3239 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address
3240 // (req_addr != NULL) or with a given alignment.
3241 // - bytes shall be a multiple of alignment.
3242 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3243 // - alignment sets the alignment at which memory shall be allocated.
3244 // It must be a multiple of allocation granularity.
3245 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3246 // req_addr or NULL.
3247 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) {
3248
3249 size_t extra_size = bytes;
3250 if (req_addr == NULL && alignment > 0) {
3251 extra_size += alignment;
3252 }
3253
3254 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE,
3255 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
3256 -1, 0);
3257 if (start == MAP_FAILED) {
3258 start = NULL;
3259 } else {
3260 if (req_addr != NULL) {
3261 if (start != req_addr) {
3262 ::munmap(start, extra_size);
3263 start = NULL;
3264 }
3265 } else {
3266 char* const start_aligned = align_up(start, alignment);
3267 char* const end_aligned = start_aligned + bytes;
3268 char* const end = start + extra_size;
3269 if (start_aligned > start) {
3270 ::munmap(start, start_aligned - start);
3271 }
3272 if (end_aligned < end) {
3273 ::munmap(end_aligned, end - end_aligned);
3274 }
3275 start = start_aligned;
3276 }
3277 }
3278 return start;
3279 }
3280
3281 static int anon_munmap(char * addr, size_t size) {
3282 return ::munmap(addr, size) == 0;
3283 }
3284
3285 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
3286 size_t alignment_hint) {
3287 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
3288 }
3289
3290 bool os::pd_release_memory(char* addr, size_t size) {
3291 return anon_munmap(addr, size);
3292 }
3293
3294 static bool linux_mprotect(char* addr, size_t size, int prot) {
3295 // Linux wants the mprotect address argument to be page aligned.
3296 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size());
3297
3298 // According to SUSv3, mprotect() should only be used with mappings
3299 // established by mmap(), and mmap() always maps whole pages. Unaligned
3300 // 'addr' likely indicates problem in the VM (e.g. trying to change
3301 // protection of malloc'ed or statically allocated memory). Check the
3302 // caller if you hit this assert.
3303 assert(addr == bottom, "sanity check");
3304
3305 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size());
3306 return ::mprotect(bottom, size, prot) == 0;
3307 }
3308
3309 // Set protections specified
3310 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
3311 bool is_committed) {
3312 unsigned int p = 0;
3313 switch (prot) {
3314 case MEM_PROT_NONE: p = PROT_NONE; break;
3315 case MEM_PROT_READ: p = PROT_READ; break;
3316 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
3317 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
3318 default:
3319 ShouldNotReachHere();
3320 }
3321 // is_committed is unused.
3322 return linux_mprotect(addr, bytes, p);
3323 }
3324
3325 bool os::guard_memory(char* addr, size_t size) {
3326 return linux_mprotect(addr, size, PROT_NONE);
3327 }
3328
3329 bool os::unguard_memory(char* addr, size_t size) {
3330 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE);
3331 }
3332
3333 bool os::Linux::transparent_huge_pages_sanity_check(bool warn,
3334 size_t page_size) {
3335 bool result = false;
3336 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,
3337 MAP_ANONYMOUS|MAP_PRIVATE,
3338 -1, 0);
3339 if (p != MAP_FAILED) {
3340 void *aligned_p = align_up(p, page_size);
3341
3342 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0;
3343
3344 munmap(p, page_size * 2);
3345 }
3346
3347 if (warn && !result) {
3348 warning("TransparentHugePages is not supported by the operating system.");
3349 }
3350
3351 return result;
3352 }
3353
3354 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) {
3355 bool result = false;
3356 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
3357 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB,
3358 -1, 0);
3359
3360 if (p != MAP_FAILED) {
3361 // We don't know if this really is a huge page or not.
3362 FILE *fp = fopen("/proc/self/maps", "r");
3363 if (fp) {
3364 while (!feof(fp)) {
3365 char chars[257];
3366 long x = 0;
3367 if (fgets(chars, sizeof(chars), fp)) {
3368 if (sscanf(chars, "%lx-%*x", &x) == 1
3369 && x == (long)p) {
3370 if (strstr (chars, "hugepage")) {
3371 result = true;
3372 break;
3373 }
3374 }
3375 }
3376 }
3377 fclose(fp);
3378 }
3379 munmap(p, page_size);
3380 }
3381
3382 if (warn && !result) {
3383 warning("HugeTLBFS is not supported by the operating system.");
3384 }
3385
3386 return result;
3387 }
3388
3389 // Set the coredump_filter bits to include largepages in core dump (bit 6)
3390 //
3391 // From the coredump_filter documentation:
3392 //
3393 // - (bit 0) anonymous private memory
3394 // - (bit 1) anonymous shared memory
3395 // - (bit 2) file-backed private memory
3396 // - (bit 3) file-backed shared memory
3397 // - (bit 4) ELF header pages in file-backed private memory areas (it is
3398 // effective only if the bit 2 is cleared)
3399 // - (bit 5) hugetlb private memory
3400 // - (bit 6) hugetlb shared memory
3401 // - (bit 7) dax private memory
3402 // - (bit 8) dax shared memory
3403 //
3404 static void set_coredump_filter(bool largepages, bool dax_shared) {
3405 FILE *f;
3406 long cdm;
3407 bool filter_changed = false;
3408
3409 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
3410 return;
3411 }
3412
3413 if (fscanf(f, "%lx", &cdm) != 1) {
3414 fclose(f);
3415 return;
3416 }
3417
3418 rewind(f);
3419
3420 if (largepages && (cdm & LARGEPAGES_BIT) == 0) {
3421 cdm |= LARGEPAGES_BIT;
3422 filter_changed = true;
3423 }
3424 if (dax_shared && (cdm & DAX_SHARED_BIT) == 0) {
3425 cdm |= DAX_SHARED_BIT;
3426 filter_changed = true;
3427 }
3428 if (filter_changed) {
3429 fprintf(f, "%#lx", cdm);
3430 }
3431
3432 fclose(f);
3433 }
3434
3435 // Large page support
3436
3437 static size_t _large_page_size = 0;
3438
3439 size_t os::Linux::find_large_page_size() {
3440 size_t large_page_size = 0;
3441
3442 // large_page_size on Linux is used to round up heap size. x86 uses either
3443 // 2M or 4M page, depending on whether PAE (Physical Address Extensions)
3444 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use
3445 // page as large as 256M.
3446 //
3447 // Here we try to figure out page size by parsing /proc/meminfo and looking
3448 // for a line with the following format:
3449 // Hugepagesize: 2048 kB
3450 //
3451 // If we can't determine the value (e.g. /proc is not mounted, or the text
3452 // format has been changed), we'll use the largest page size supported by
3453 // the processor.
3454
3455 #ifndef ZERO
3456 large_page_size =
3457 AARCH64_ONLY(2 * M)
3458 AMD64_ONLY(2 * M)
3459 ARM32_ONLY(2 * M)
3460 IA32_ONLY(4 * M)
3461 IA64_ONLY(256 * M)
3462 PPC_ONLY(4 * M)
3463 S390_ONLY(1 * M)
3464 SPARC_ONLY(4 * M);
3465 #endif // ZERO
3466
3467 FILE *fp = fopen("/proc/meminfo", "r");
3468 if (fp) {
3469 while (!feof(fp)) {
3470 int x = 0;
3471 char buf[16];
3472 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) {
3473 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) {
3474 large_page_size = x * K;
3475 break;
3476 }
3477 } else {
3478 // skip to next line
3479 for (;;) {
3480 int ch = fgetc(fp);
3481 if (ch == EOF || ch == (int)'\n') break;
3482 }
3483 }
3484 }
3485 fclose(fp);
3486 }
3487
3488 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) {
3489 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is "
3490 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size),
3491 proper_unit_for_byte_size(large_page_size));
3492 }
3493
3494 return large_page_size;
3495 }
3496
3497 size_t os::Linux::setup_large_page_size() {
3498 _large_page_size = Linux::find_large_page_size();
3499 const size_t default_page_size = (size_t)Linux::page_size();
3500 if (_large_page_size > default_page_size) {
3501 _page_sizes[0] = _large_page_size;
3502 _page_sizes[1] = default_page_size;
3503 _page_sizes[2] = 0;
3504 }
3505
3506 return _large_page_size;
3507 }
3508
3509 bool os::Linux::setup_large_page_type(size_t page_size) {
3510 if (FLAG_IS_DEFAULT(UseHugeTLBFS) &&
3511 FLAG_IS_DEFAULT(UseSHM) &&
3512 FLAG_IS_DEFAULT(UseTransparentHugePages)) {
3513
3514 // The type of large pages has not been specified by the user.
3515
3516 // Try UseHugeTLBFS and then UseSHM.
3517 UseHugeTLBFS = UseSHM = true;
3518
3519 // Don't try UseTransparentHugePages since there are known
3520 // performance issues with it turned on. This might change in the future.
3521 UseTransparentHugePages = false;
3522 }
3523
3524 if (UseTransparentHugePages) {
3525 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages);
3526 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) {
3527 UseHugeTLBFS = false;
3528 UseSHM = false;
3529 return true;
3530 }
3531 UseTransparentHugePages = false;
3532 }
3533
3534 if (UseHugeTLBFS) {
3535 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS);
3536 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) {
3537 UseSHM = false;
3538 return true;
3539 }
3540 UseHugeTLBFS = false;
3541 }
3542
3543 return UseSHM;
3544 }
3545
3546 void os::large_page_init() {
3547 if (!UseLargePages &&
3548 !UseTransparentHugePages &&
3549 !UseHugeTLBFS &&
3550 !UseSHM) {
3551 // Not using large pages.
3552 return;
3553 }
3554
3555 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) {
3556 // The user explicitly turned off large pages.
3557 // Ignore the rest of the large pages flags.
3558 UseTransparentHugePages = false;
3559 UseHugeTLBFS = false;
3560 UseSHM = false;
3561 return;
3562 }
3563
3564 size_t large_page_size = Linux::setup_large_page_size();
3565 UseLargePages = Linux::setup_large_page_type(large_page_size);
3566
3567 set_coredump_filter(true /*largepages*/, false /*dax_shared*/);
3568 }
3569
3570 #ifndef SHM_HUGETLB
3571 #define SHM_HUGETLB 04000
3572 #endif
3573
3574 #define shm_warning_format(format, ...) \
3575 do { \
3576 if (UseLargePages && \
3577 (!FLAG_IS_DEFAULT(UseLargePages) || \
3578 !FLAG_IS_DEFAULT(UseSHM) || \
3579 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \
3580 warning(format, __VA_ARGS__); \
3581 } \
3582 } while (0)
3583
3584 #define shm_warning(str) shm_warning_format("%s", str)
3585
3586 #define shm_warning_with_errno(str) \
3587 do { \
3588 int err = errno; \
3589 shm_warning_format(str " (error = %d)", err); \
3590 } while (0)
3591
3592 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) {
3593 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment");
3594
3595 if (!is_aligned(alignment, SHMLBA)) {
3596 assert(false, "Code below assumes that alignment is at least SHMLBA aligned");
3597 return NULL;
3598 }
3599
3600 // To ensure that we get 'alignment' aligned memory from shmat,
3601 // we pre-reserve aligned virtual memory and then attach to that.
3602
3603 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL);
3604 if (pre_reserved_addr == NULL) {
3605 // Couldn't pre-reserve aligned memory.
3606 shm_warning("Failed to pre-reserve aligned memory for shmat.");
3607 return NULL;
3608 }
3609
3610 // SHM_REMAP is needed to allow shmat to map over an existing mapping.
3611 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP);
3612
3613 if ((intptr_t)addr == -1) {
3614 int err = errno;
3615 shm_warning_with_errno("Failed to attach shared memory.");
3616
3617 assert(err != EACCES, "Unexpected error");
3618 assert(err != EIDRM, "Unexpected error");
3619 assert(err != EINVAL, "Unexpected error");
3620
3621 // Since we don't know if the kernel unmapped the pre-reserved memory area
3622 // we can't unmap it, since that would potentially unmap memory that was
3623 // mapped from other threads.
3624 return NULL;
3625 }
3626
3627 return addr;
3628 }
3629
3630 static char* shmat_at_address(int shmid, char* req_addr) {
3631 if (!is_aligned(req_addr, SHMLBA)) {
3632 assert(false, "Requested address needs to be SHMLBA aligned");
3633 return NULL;
3634 }
3635
3636 char* addr = (char*)shmat(shmid, req_addr, 0);
3637
3638 if ((intptr_t)addr == -1) {
3639 shm_warning_with_errno("Failed to attach shared memory.");
3640 return NULL;
3641 }
3642
3643 return addr;
3644 }
3645
3646 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) {
3647 // If a req_addr has been provided, we assume that the caller has already aligned the address.
3648 if (req_addr != NULL) {
3649 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size");
3650 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment");
3651 return shmat_at_address(shmid, req_addr);
3652 }
3653
3654 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically
3655 // return large page size aligned memory addresses when req_addr == NULL.
3656 // However, if the alignment is larger than the large page size, we have
3657 // to manually ensure that the memory returned is 'alignment' aligned.
3658 if (alignment > os::large_page_size()) {
3659 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size");
3660 return shmat_with_alignment(shmid, bytes, alignment);
3661 } else {
3662 return shmat_at_address(shmid, NULL);
3663 }
3664 }
3665
3666 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment,
3667 char* req_addr, bool exec) {
3668 // "exec" is passed in but not used. Creating the shared image for
3669 // the code cache doesn't have an SHM_X executable permission to check.
3670 assert(UseLargePages && UseSHM, "only for SHM large pages");
3671 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
3672 assert(is_aligned(req_addr, alignment), "Unaligned address");
3673
3674 if (!is_aligned(bytes, os::large_page_size())) {
3675 return NULL; // Fallback to small pages.
3676 }
3677
3678 // Create a large shared memory region to attach to based on size.
3679 // Currently, size is the total size of the heap.
3680 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);
3681 if (shmid == -1) {
3682 // Possible reasons for shmget failure:
3683 // 1. shmmax is too small for Java heap.
3684 // > check shmmax value: cat /proc/sys/kernel/shmmax
3685 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
3686 // 2. not enough large page memory.
3687 // > check available large pages: cat /proc/meminfo
3688 // > increase amount of large pages:
3689 // echo new_value > /proc/sys/vm/nr_hugepages
3690 // Note 1: different Linux may use different name for this property,
3691 // e.g. on Redhat AS-3 it is "hugetlb_pool".
3692 // Note 2: it's possible there's enough physical memory available but
3693 // they are so fragmented after a long run that they can't
3694 // coalesce into large pages. Try to reserve large pages when
3695 // the system is still "fresh".
3696 shm_warning_with_errno("Failed to reserve shared memory.");
3697 return NULL;
3698 }
3699
3700 // Attach to the region.
3701 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr);
3702
3703 // Remove shmid. If shmat() is successful, the actual shared memory segment
3704 // will be deleted when it's detached by shmdt() or when the process
3705 // terminates. If shmat() is not successful this will remove the shared
3706 // segment immediately.
3707 shmctl(shmid, IPC_RMID, NULL);
3708
3709 return addr;
3710 }
3711
3712 static void warn_on_large_pages_failure(char* req_addr, size_t bytes,
3713 int error) {
3714 assert(error == ENOMEM, "Only expect to fail if no memory is available");
3715
3716 bool warn_on_failure = UseLargePages &&
3717 (!FLAG_IS_DEFAULT(UseLargePages) ||
3718 !FLAG_IS_DEFAULT(UseHugeTLBFS) ||
3719 !FLAG_IS_DEFAULT(LargePageSizeInBytes));
3720
3721 if (warn_on_failure) {
3722 char msg[128];
3723 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: "
3724 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error);
3725 warning("%s", msg);
3726 }
3727 }
3728
3729 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes,
3730 char* req_addr,
3731 bool exec) {
3732 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
3733 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size");
3734 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
3735
3736 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
3737 char* addr = (char*)::mmap(req_addr, bytes, prot,
3738 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB,
3739 -1, 0);
3740
3741 if (addr == MAP_FAILED) {
3742 warn_on_large_pages_failure(req_addr, bytes, errno);
3743 return NULL;
3744 }
3745
3746 assert(is_aligned(addr, os::large_page_size()), "Must be");
3747
3748 return addr;
3749 }
3750
3751 // Reserve memory using mmap(MAP_HUGETLB).
3752 // - bytes shall be a multiple of alignment.
3753 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3754 // - alignment sets the alignment at which memory shall be allocated.
3755 // It must be a multiple of allocation granularity.
3756 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3757 // req_addr or NULL.
3758 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes,
3759 size_t alignment,
3760 char* req_addr,
3761 bool exec) {
3762 size_t large_page_size = os::large_page_size();
3763 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes");
3764
3765 assert(is_aligned(req_addr, alignment), "Must be");
3766 assert(is_aligned(bytes, alignment), "Must be");
3767
3768 // First reserve - but not commit - the address range in small pages.
3769 char* const start = anon_mmap_aligned(bytes, alignment, req_addr);
3770
3771 if (start == NULL) {
3772 return NULL;
3773 }
3774
3775 assert(is_aligned(start, alignment), "Must be");
3776
3777 char* end = start + bytes;
3778
3779 // Find the regions of the allocated chunk that can be promoted to large pages.
3780 char* lp_start = align_up(start, large_page_size);
3781 char* lp_end = align_down(end, large_page_size);
3782
3783 size_t lp_bytes = lp_end - lp_start;
3784
3785 assert(is_aligned(lp_bytes, large_page_size), "Must be");
3786
3787 if (lp_bytes == 0) {
3788 // The mapped region doesn't even span the start and the end of a large page.
3789 // Fall back to allocate a non-special area.
3790 ::munmap(start, end - start);
3791 return NULL;
3792 }
3793
3794 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
3795
3796 void* result;
3797
3798 // Commit small-paged leading area.
3799 if (start != lp_start) {
3800 result = ::mmap(start, lp_start - start, prot,
3801 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
3802 -1, 0);
3803 if (result == MAP_FAILED) {
3804 ::munmap(lp_start, end - lp_start);
3805 return NULL;
3806 }
3807 }
3808
3809 // Commit large-paged area.
3810 result = ::mmap(lp_start, lp_bytes, prot,
3811 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB,
3812 -1, 0);
3813 if (result == MAP_FAILED) {
3814 warn_on_large_pages_failure(lp_start, lp_bytes, errno);
3815 // If the mmap above fails, the large pages region will be unmapped and we
3816 // have regions before and after with small pages. Release these regions.
3817 //
3818 // | mapped | unmapped | mapped |
3819 // ^ ^ ^ ^
3820 // start lp_start lp_end end
3821 //
3822 ::munmap(start, lp_start - start);
3823 ::munmap(lp_end, end - lp_end);
3824 return NULL;
3825 }
3826
3827 // Commit small-paged trailing area.
3828 if (lp_end != end) {
3829 result = ::mmap(lp_end, end - lp_end, prot,
3830 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
3831 -1, 0);
3832 if (result == MAP_FAILED) {
3833 ::munmap(start, lp_end - start);
3834 return NULL;
3835 }
3836 }
3837
3838 return start;
3839 }
3840
3841 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes,
3842 size_t alignment,
3843 char* req_addr,
3844 bool exec) {
3845 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
3846 assert(is_aligned(req_addr, alignment), "Must be");
3847 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be");
3848 assert(is_power_of_2(os::large_page_size()), "Must be");
3849 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes");
3850
3851 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) {
3852 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec);
3853 } else {
3854 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec);
3855 }
3856 }
3857
3858 char* os::reserve_memory_special(size_t bytes, size_t alignment,
3859 char* req_addr, bool exec) {
3860 assert(UseLargePages, "only for large pages");
3861
3862 char* addr;
3863 if (UseSHM) {
3864 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec);
3865 } else {
3866 assert(UseHugeTLBFS, "must be");
3867 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec);
3868 }
3869
3870 if (addr != NULL) {
3871 if (UseNUMAInterleaving) {
3872 numa_make_global(addr, bytes);
3873 }
3874
3875 // The memory is committed
3876 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
3877 }
3878
3879 return addr;
3880 }
3881
3882 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) {
3883 // detaching the SHM segment will also delete it, see reserve_memory_special_shm()
3884 return shmdt(base) == 0;
3885 }
3886
3887 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) {
3888 return pd_release_memory(base, bytes);
3889 }
3890
3891 bool os::release_memory_special(char* base, size_t bytes) {
3892 bool res;
3893 if (MemTracker::tracking_level() > NMT_minimal) {
3894 Tracker tkr(Tracker::release);
3895 res = os::Linux::release_memory_special_impl(base, bytes);
3896 if (res) {
3897 tkr.record((address)base, bytes);
3898 }
3899
3900 } else {
3901 res = os::Linux::release_memory_special_impl(base, bytes);
3902 }
3903 return res;
3904 }
3905
3906 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) {
3907 assert(UseLargePages, "only for large pages");
3908 bool res;
3909
3910 if (UseSHM) {
3911 res = os::Linux::release_memory_special_shm(base, bytes);
3912 } else {
3913 assert(UseHugeTLBFS, "must be");
3914 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes);
3915 }
3916 return res;
3917 }
3918
3919 size_t os::large_page_size() {
3920 return _large_page_size;
3921 }
3922
3923 // With SysV SHM the entire memory region must be allocated as shared
3924 // memory.
3925 // HugeTLBFS allows application to commit large page memory on demand.
3926 // However, when committing memory with HugeTLBFS fails, the region
3927 // that was supposed to be committed will lose the old reservation
3928 // and allow other threads to steal that memory region. Because of this
3929 // behavior we can't commit HugeTLBFS memory.
3930 bool os::can_commit_large_page_memory() {
3931 return UseTransparentHugePages;
3932 }
3933
3934 bool os::can_execute_large_page_memory() {
3935 return UseTransparentHugePages || UseHugeTLBFS;
3936 }
3937
3938 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
3939 assert(file_desc >= 0, "file_desc is not valid");
3940 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
3941 if (result != NULL) {
3942 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
3943 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
3944 }
3945 }
3946 return result;
3947 }
3948
3949 // Reserve memory at an arbitrary address, only if that area is
3950 // available (and not reserved for something else).
3951
3952 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
3953 const int max_tries = 10;
3954 char* base[max_tries];
3955 size_t size[max_tries];
3956 const size_t gap = 0x000000;
3957
3958 // Assert only that the size is a multiple of the page size, since
3959 // that's all that mmap requires, and since that's all we really know
3960 // about at this low abstraction level. If we need higher alignment,
3961 // we can either pass an alignment to this method or verify alignment
3962 // in one of the methods further up the call chain. See bug 5044738.
3963 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
3964
3965 // Repeatedly allocate blocks until the block is allocated at the
3966 // right spot.
3967
3968 // Linux mmap allows caller to pass an address as hint; give it a try first,
3969 // if kernel honors the hint then we can return immediately.
3970 char * addr = anon_mmap(requested_addr, bytes, false);
3971 if (addr == requested_addr) {
3972 return requested_addr;
3973 }
3974
3975 if (addr != NULL) {
3976 // mmap() is successful but it fails to reserve at the requested address
3977 anon_munmap(addr, bytes);
3978 }
3979
3980 int i;
3981 for (i = 0; i < max_tries; ++i) {
3982 base[i] = reserve_memory(bytes);
3983
3984 if (base[i] != NULL) {
3985 // Is this the block we wanted?
3986 if (base[i] == requested_addr) {
3987 size[i] = bytes;
3988 break;
3989 }
3990
3991 // Does this overlap the block we wanted? Give back the overlapped
3992 // parts and try again.
3993
3994 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i];
3995 if (top_overlap >= 0 && (size_t)top_overlap < bytes) {
3996 unmap_memory(base[i], top_overlap);
3997 base[i] += top_overlap;
3998 size[i] = bytes - top_overlap;
3999 } else {
4000 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr;
4001 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) {
4002 unmap_memory(requested_addr, bottom_overlap);
4003 size[i] = bytes - bottom_overlap;
4004 } else {
4005 size[i] = bytes;
4006 }
4007 }
4008 }
4009 }
4010
4011 // Give back the unused reserved pieces.
4012
4013 for (int j = 0; j < i; ++j) {
4014 if (base[j] != NULL) {
4015 unmap_memory(base[j], size[j]);
4016 }
4017 }
4018
4019 if (i < max_tries) {
4020 return requested_addr;
4021 } else {
4022 return NULL;
4023 }
4024 }
4025
4026 size_t os::read(int fd, void *buf, unsigned int nBytes) {
4027 return ::read(fd, buf, nBytes);
4028 }
4029
4030 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
4031 return ::pread(fd, buf, nBytes, offset);
4032 }
4033
4034 // Short sleep, direct OS call.
4035 //
4036 // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee
4037 // sched_yield(2) will actually give up the CPU:
4038 //
4039 // * Alone on this pariticular CPU, keeps running.
4040 // * Before the introduction of "skip_buddy" with "compat_yield" disabled
4041 // (pre 2.6.39).
4042 //
4043 // So calling this with 0 is an alternative.
4044 //
4045 void os::naked_short_sleep(jlong ms) {
4046 struct timespec req;
4047
4048 assert(ms < 1000, "Un-interruptable sleep, short time use only");
4049 req.tv_sec = 0;
4050 if (ms > 0) {
4051 req.tv_nsec = (ms % 1000) * 1000000;
4052 } else {
4053 req.tv_nsec = 1;
4054 }
4055
4056 nanosleep(&req, NULL);
4057
4058 return;
4059 }
4060
4061 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
4062 void os::infinite_sleep() {
4063 while (true) { // sleep forever ...
4064 ::sleep(100); // ... 100 seconds at a time
4065 }
4066 }
4067
4068 // Used to convert frequent JVM_Yield() to nops
4069 bool os::dont_yield() {
4070 return DontYieldALot;
4071 }
4072
4073 void os::naked_yield() {
4074 sched_yield();
4075 }
4076
4077 ////////////////////////////////////////////////////////////////////////////////
4078 // thread priority support
4079
4080 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER
4081 // only supports dynamic priority, static priority must be zero. For real-time
4082 // applications, Linux supports SCHED_RR which allows static priority (1-99).
4083 // However, for large multi-threaded applications, SCHED_RR is not only slower
4084 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
4085 // of 5 runs - Sep 2005).
4086 //
4087 // The following code actually changes the niceness of kernel-thread/LWP. It
4088 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
4089 // not the entire user process, and user level threads are 1:1 mapped to kernel
4090 // threads. It has always been the case, but could change in the future. For
4091 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
4092 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
4093
4094 int os::java_to_os_priority[CriticalPriority + 1] = {
4095 19, // 0 Entry should never be used
4096
4097 4, // 1 MinPriority
4098 3, // 2
4099 2, // 3
4100
4101 1, // 4
4102 0, // 5 NormPriority
4103 -1, // 6
4104
4105 -2, // 7
4106 -3, // 8
4107 -4, // 9 NearMaxPriority
4108
4109 -5, // 10 MaxPriority
4110
4111 -5 // 11 CriticalPriority
4112 };
4113
4114 static int prio_init() {
4115 if (ThreadPriorityPolicy == 1) {
4116 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
4117 // if effective uid is not root. Perhaps, a more elegant way of doing
4118 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
4119 if (geteuid() != 0) {
4120 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
4121 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux");
4122 }
4123 ThreadPriorityPolicy = 0;
4124 }
4125 }
4126 if (UseCriticalJavaThreadPriority) {
4127 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
4128 }
4129 return 0;
4130 }
4131
4132 OSReturn os::set_native_priority(Thread* thread, int newpri) {
4133 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
4134
4135 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
4136 return (ret == 0) ? OS_OK : OS_ERR;
4137 }
4138
4139 OSReturn os::get_native_priority(const Thread* const thread,
4140 int *priority_ptr) {
4141 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
4142 *priority_ptr = java_to_os_priority[NormPriority];
4143 return OS_OK;
4144 }
4145
4146 errno = 0;
4147 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
4148 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
4149 }
4150
4151 ////////////////////////////////////////////////////////////////////////////////
4152 // suspend/resume support
4153
4154 // The low-level signal-based suspend/resume support is a remnant from the
4155 // old VM-suspension that used to be for java-suspension, safepoints etc,
4156 // within hotspot. Currently used by JFR's OSThreadSampler
4157 //
4158 // The remaining code is greatly simplified from the more general suspension
4159 // code that used to be used.
4160 //
4161 // The protocol is quite simple:
4162 // - suspend:
4163 // - sends a signal to the target thread
4164 // - polls the suspend state of the osthread using a yield loop
4165 // - target thread signal handler (SR_handler) sets suspend state
4166 // and blocks in sigsuspend until continued
4167 // - resume:
4168 // - sets target osthread state to continue
4169 // - sends signal to end the sigsuspend loop in the SR_handler
4170 //
4171 // Note that the SR_lock plays no role in this suspend/resume protocol,
4172 // but is checked for NULL in SR_handler as a thread termination indicator.
4173 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
4174 //
4175 // Note that resume_clear_context() and suspend_save_context() are needed
4176 // by SR_handler(), so that fetch_frame_from_ucontext() works,
4177 // which in part is used by:
4178 // - Forte Analyzer: AsyncGetCallTrace()
4179 // - StackBanging: get_frame_at_stack_banging_point()
4180
4181 static void resume_clear_context(OSThread *osthread) {
4182 osthread->set_ucontext(NULL);
4183 osthread->set_siginfo(NULL);
4184 }
4185
4186 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo,
4187 ucontext_t* context) {
4188 osthread->set_ucontext(context);
4189 osthread->set_siginfo(siginfo);
4190 }
4191
4192 // Handler function invoked when a thread's execution is suspended or
4193 // resumed. We have to be careful that only async-safe functions are
4194 // called here (Note: most pthread functions are not async safe and
4195 // should be avoided.)
4196 //
4197 // Note: sigwait() is a more natural fit than sigsuspend() from an
4198 // interface point of view, but sigwait() prevents the signal hander
4199 // from being run. libpthread would get very confused by not having
4200 // its signal handlers run and prevents sigwait()'s use with the
4201 // mutex granting granting signal.
4202 //
4203 // Currently only ever called on the VMThread and JavaThreads (PC sampling)
4204 //
4205 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
4206 // Save and restore errno to avoid confusing native code with EINTR
4207 // after sigsuspend.
4208 int old_errno = errno;
4209
4210 Thread* thread = Thread::current_or_null_safe();
4211 assert(thread != NULL, "Missing current thread in SR_handler");
4212
4213 // On some systems we have seen signal delivery get "stuck" until the signal
4214 // mask is changed as part of thread termination. Check that the current thread
4215 // has not already terminated (via SR_lock()) - else the following assertion
4216 // will fail because the thread is no longer a JavaThread as the ~JavaThread
4217 // destructor has completed.
4218
4219 if (thread->SR_lock() == NULL) {
4220 return;
4221 }
4222
4223 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
4224
4225 OSThread* osthread = thread->osthread();
4226
4227 os::SuspendResume::State current = osthread->sr.state();
4228 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
4229 suspend_save_context(osthread, siginfo, context);
4230
4231 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
4232 os::SuspendResume::State state = osthread->sr.suspended();
4233 if (state == os::SuspendResume::SR_SUSPENDED) {
4234 sigset_t suspend_set; // signals for sigsuspend()
4235 sigemptyset(&suspend_set);
4236 // get current set of blocked signals and unblock resume signal
4237 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
4238 sigdelset(&suspend_set, SR_signum);
4239
4240 sr_semaphore.signal();
4241 // wait here until we are resumed
4242 while (1) {
4243 sigsuspend(&suspend_set);
4244
4245 os::SuspendResume::State result = osthread->sr.running();
4246 if (result == os::SuspendResume::SR_RUNNING) {
4247 sr_semaphore.signal();
4248 break;
4249 }
4250 }
4251
4252 } else if (state == os::SuspendResume::SR_RUNNING) {
4253 // request was cancelled, continue
4254 } else {
4255 ShouldNotReachHere();
4256 }
4257
4258 resume_clear_context(osthread);
4259 } else if (current == os::SuspendResume::SR_RUNNING) {
4260 // request was cancelled, continue
4261 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
4262 // ignore
4263 } else {
4264 // ignore
4265 }
4266
4267 errno = old_errno;
4268 }
4269
4270 static int SR_initialize() {
4271 struct sigaction act;
4272 char *s;
4273
4274 // Get signal number to use for suspend/resume
4275 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
4276 int sig = ::strtol(s, 0, 10);
4277 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769.
4278 sig < NSIG) { // Must be legal signal and fit into sigflags[].
4279 SR_signum = sig;
4280 } else {
4281 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
4282 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
4283 }
4284 }
4285
4286 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
4287 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
4288
4289 sigemptyset(&SR_sigset);
4290 sigaddset(&SR_sigset, SR_signum);
4291
4292 // Set up signal handler for suspend/resume
4293 act.sa_flags = SA_RESTART|SA_SIGINFO;
4294 act.sa_handler = (void (*)(int)) SR_handler;
4295
4296 // SR_signum is blocked by default.
4297 // 4528190 - We also need to block pthread restart signal (32 on all
4298 // supported Linux platforms). Note that LinuxThreads need to block
4299 // this signal for all threads to work properly. So we don't have
4300 // to use hard-coded signal number when setting up the mask.
4301 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
4302
4303 if (sigaction(SR_signum, &act, 0) == -1) {
4304 return -1;
4305 }
4306
4307 // Save signal flag
4308 os::Linux::set_our_sigflags(SR_signum, act.sa_flags);
4309 return 0;
4310 }
4311
4312 static int sr_notify(OSThread* osthread) {
4313 int status = pthread_kill(osthread->pthread_id(), SR_signum);
4314 assert_status(status == 0, status, "pthread_kill");
4315 return status;
4316 }
4317
4318 // "Randomly" selected value for how long we want to spin
4319 // before bailing out on suspending a thread, also how often
4320 // we send a signal to a thread we want to resume
4321 static const int RANDOMLY_LARGE_INTEGER = 1000000;
4322 static const int RANDOMLY_LARGE_INTEGER2 = 100;
4323
4324 // returns true on success and false on error - really an error is fatal
4325 // but this seems the normal response to library errors
4326 static bool do_suspend(OSThread* osthread) {
4327 assert(osthread->sr.is_running(), "thread should be running");
4328 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
4329
4330 // mark as suspended and send signal
4331 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
4332 // failed to switch, state wasn't running?
4333 ShouldNotReachHere();
4334 return false;
4335 }
4336
4337 if (sr_notify(osthread) != 0) {
4338 ShouldNotReachHere();
4339 }
4340
4341 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
4342 while (true) {
4343 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) {
4344 break;
4345 } else {
4346 // timeout
4347 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
4348 if (cancelled == os::SuspendResume::SR_RUNNING) {
4349 return false;
4350 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
4351 // make sure that we consume the signal on the semaphore as well
4352 sr_semaphore.wait();
4353 break;
4354 } else {
4355 ShouldNotReachHere();
4356 return false;
4357 }
4358 }
4359 }
4360
4361 guarantee(osthread->sr.is_suspended(), "Must be suspended");
4362 return true;
4363 }
4364
4365 static void do_resume(OSThread* osthread) {
4366 assert(osthread->sr.is_suspended(), "thread should be suspended");
4367 assert(!sr_semaphore.trywait(), "invalid semaphore state");
4368
4369 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
4370 // failed to switch to WAKEUP_REQUEST
4371 ShouldNotReachHere();
4372 return;
4373 }
4374
4375 while (true) {
4376 if (sr_notify(osthread) == 0) {
4377 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) {
4378 if (osthread->sr.is_running()) {
4379 return;
4380 }
4381 }
4382 } else {
4383 ShouldNotReachHere();
4384 }
4385 }
4386
4387 guarantee(osthread->sr.is_running(), "Must be running!");
4388 }
4389
4390 ///////////////////////////////////////////////////////////////////////////////////
4391 // signal handling (except suspend/resume)
4392
4393 // This routine may be used by user applications as a "hook" to catch signals.
4394 // The user-defined signal handler must pass unrecognized signals to this
4395 // routine, and if it returns true (non-zero), then the signal handler must
4396 // return immediately. If the flag "abort_if_unrecognized" is true, then this
4397 // routine will never retun false (zero), but instead will execute a VM panic
4398 // routine kill the process.
4399 //
4400 // If this routine returns false, it is OK to call it again. This allows
4401 // the user-defined signal handler to perform checks either before or after
4402 // the VM performs its own checks. Naturally, the user code would be making
4403 // a serious error if it tried to handle an exception (such as a null check
4404 // or breakpoint) that the VM was generating for its own correct operation.
4405 //
4406 // This routine may recognize any of the following kinds of signals:
4407 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
4408 // It should be consulted by handlers for any of those signals.
4409 //
4410 // The caller of this routine must pass in the three arguments supplied
4411 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
4412 // field of the structure passed to sigaction(). This routine assumes that
4413 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
4414 //
4415 // Note that the VM will print warnings if it detects conflicting signal
4416 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
4417 //
4418 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo,
4419 siginfo_t* siginfo,
4420 void* ucontext,
4421 int abort_if_unrecognized);
4422
4423 static void signalHandler(int sig, siginfo_t* info, void* uc) {
4424 assert(info != NULL && uc != NULL, "it must be old kernel");
4425 int orig_errno = errno; // Preserve errno value over signal handler.
4426 JVM_handle_linux_signal(sig, info, uc, true);
4427 errno = orig_errno;
4428 }
4429
4430
4431 // This boolean allows users to forward their own non-matching signals
4432 // to JVM_handle_linux_signal, harmlessly.
4433 bool os::Linux::signal_handlers_are_installed = false;
4434
4435 // For signal-chaining
4436 struct sigaction sigact[NSIG];
4437 uint64_t sigs = 0;
4438 #if (64 < NSIG-1)
4439 #error "Not all signals can be encoded in sigs. Adapt its type!"
4440 #endif
4441 bool os::Linux::libjsig_is_loaded = false;
4442 typedef struct sigaction *(*get_signal_t)(int);
4443 get_signal_t os::Linux::get_signal_action = NULL;
4444
4445 struct sigaction* os::Linux::get_chained_signal_action(int sig) {
4446 struct sigaction *actp = NULL;
4447
4448 if (libjsig_is_loaded) {
4449 // Retrieve the old signal handler from libjsig
4450 actp = (*get_signal_action)(sig);
4451 }
4452 if (actp == NULL) {
4453 // Retrieve the preinstalled signal handler from jvm
4454 actp = get_preinstalled_handler(sig);
4455 }
4456
4457 return actp;
4458 }
4459
4460 static bool call_chained_handler(struct sigaction *actp, int sig,
4461 siginfo_t *siginfo, void *context) {
4462 // Call the old signal handler
4463 if (actp->sa_handler == SIG_DFL) {
4464 // It's more reasonable to let jvm treat it as an unexpected exception
4465 // instead of taking the default action.
4466 return false;
4467 } else if (actp->sa_handler != SIG_IGN) {
4468 if ((actp->sa_flags & SA_NODEFER) == 0) {
4469 // automaticlly block the signal
4470 sigaddset(&(actp->sa_mask), sig);
4471 }
4472
4473 sa_handler_t hand = NULL;
4474 sa_sigaction_t sa = NULL;
4475 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
4476 // retrieve the chained handler
4477 if (siginfo_flag_set) {
4478 sa = actp->sa_sigaction;
4479 } else {
4480 hand = actp->sa_handler;
4481 }
4482
4483 if ((actp->sa_flags & SA_RESETHAND) != 0) {
4484 actp->sa_handler = SIG_DFL;
4485 }
4486
4487 // try to honor the signal mask
4488 sigset_t oset;
4489 sigemptyset(&oset);
4490 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
4491
4492 // call into the chained handler
4493 if (siginfo_flag_set) {
4494 (*sa)(sig, siginfo, context);
4495 } else {
4496 (*hand)(sig);
4497 }
4498
4499 // restore the signal mask
4500 pthread_sigmask(SIG_SETMASK, &oset, NULL);
4501 }
4502 // Tell jvm's signal handler the signal is taken care of.
4503 return true;
4504 }
4505
4506 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) {
4507 bool chained = false;
4508 // signal-chaining
4509 if (UseSignalChaining) {
4510 struct sigaction *actp = get_chained_signal_action(sig);
4511 if (actp != NULL) {
4512 chained = call_chained_handler(actp, sig, siginfo, context);
4513 }
4514 }
4515 return chained;
4516 }
4517
4518 struct sigaction* os::Linux::get_preinstalled_handler(int sig) {
4519 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) {
4520 return &sigact[sig];
4521 }
4522 return NULL;
4523 }
4524
4525 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
4526 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4527 sigact[sig] = oldAct;
4528 sigs |= (uint64_t)1 << (sig-1);
4529 }
4530
4531 // for diagnostic
4532 int sigflags[NSIG];
4533
4534 int os::Linux::get_our_sigflags(int sig) {
4535 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4536 return sigflags[sig];
4537 }
4538
4539 void os::Linux::set_our_sigflags(int sig, int flags) {
4540 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4541 if (sig > 0 && sig < NSIG) {
4542 sigflags[sig] = flags;
4543 }
4544 }
4545
4546 void os::Linux::set_signal_handler(int sig, bool set_installed) {
4547 // Check for overwrite.
4548 struct sigaction oldAct;
4549 sigaction(sig, (struct sigaction*)NULL, &oldAct);
4550
4551 void* oldhand = oldAct.sa_sigaction
4552 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4553 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4554 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
4555 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
4556 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
4557 if (AllowUserSignalHandlers || !set_installed) {
4558 // Do not overwrite; user takes responsibility to forward to us.
4559 return;
4560 } else if (UseSignalChaining) {
4561 // save the old handler in jvm
4562 save_preinstalled_handler(sig, oldAct);
4563 // libjsig also interposes the sigaction() call below and saves the
4564 // old sigaction on it own.
4565 } else {
4566 fatal("Encountered unexpected pre-existing sigaction handler "
4567 "%#lx for signal %d.", (long)oldhand, sig);
4568 }
4569 }
4570
4571 struct sigaction sigAct;
4572 sigfillset(&(sigAct.sa_mask));
4573 sigAct.sa_handler = SIG_DFL;
4574 if (!set_installed) {
4575 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4576 } else {
4577 sigAct.sa_sigaction = signalHandler;
4578 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4579 }
4580 // Save flags, which are set by ours
4581 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4582 sigflags[sig] = sigAct.sa_flags;
4583
4584 int ret = sigaction(sig, &sigAct, &oldAct);
4585 assert(ret == 0, "check");
4586
4587 void* oldhand2 = oldAct.sa_sigaction
4588 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4589 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4590 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
4591 }
4592
4593 // install signal handlers for signals that HotSpot needs to
4594 // handle in order to support Java-level exception handling.
4595
4596 void os::Linux::install_signal_handlers() {
4597 if (!signal_handlers_are_installed) {
4598 signal_handlers_are_installed = true;
4599
4600 // signal-chaining
4601 typedef void (*signal_setting_t)();
4602 signal_setting_t begin_signal_setting = NULL;
4603 signal_setting_t end_signal_setting = NULL;
4604 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4605 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
4606 if (begin_signal_setting != NULL) {
4607 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4608 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
4609 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
4610 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
4611 libjsig_is_loaded = true;
4612 assert(UseSignalChaining, "should enable signal-chaining");
4613 }
4614 if (libjsig_is_loaded) {
4615 // Tell libjsig jvm is setting signal handlers
4616 (*begin_signal_setting)();
4617 }
4618
4619 set_signal_handler(SIGSEGV, true);
4620 set_signal_handler(SIGPIPE, true);
4621 set_signal_handler(SIGBUS, true);
4622 set_signal_handler(SIGILL, true);
4623 set_signal_handler(SIGFPE, true);
4624 #if defined(PPC64)
4625 set_signal_handler(SIGTRAP, true);
4626 #endif
4627 set_signal_handler(SIGXFSZ, true);
4628
4629 if (libjsig_is_loaded) {
4630 // Tell libjsig jvm finishes setting signal handlers
4631 (*end_signal_setting)();
4632 }
4633
4634 // We don't activate signal checker if libjsig is in place, we trust ourselves
4635 // and if UserSignalHandler is installed all bets are off.
4636 // Log that signal checking is off only if -verbose:jni is specified.
4637 if (CheckJNICalls) {
4638 if (libjsig_is_loaded) {
4639 if (PrintJNIResolving) {
4640 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
4641 }
4642 check_signals = false;
4643 }
4644 if (AllowUserSignalHandlers) {
4645 if (PrintJNIResolving) {
4646 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
4647 }
4648 check_signals = false;
4649 }
4650 }
4651 }
4652 }
4653
4654 // This is the fastest way to get thread cpu time on Linux.
4655 // Returns cpu time (user+sys) for any thread, not only for current.
4656 // POSIX compliant clocks are implemented in the kernels 2.6.16+.
4657 // It might work on 2.6.10+ with a special kernel/glibc patch.
4658 // For reference, please, see IEEE Std 1003.1-2004:
4659 // http://www.unix.org/single_unix_specification
4660
4661 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) {
4662 struct timespec tp;
4663 int rc = os::Posix::clock_gettime(clockid, &tp);
4664 assert(rc == 0, "clock_gettime is expected to return 0 code");
4665
4666 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec;
4667 }
4668
4669 void os::Linux::initialize_os_info() {
4670 assert(_os_version == 0, "OS info already initialized");
4671
4672 struct utsname _uname;
4673
4674 uint32_t major;
4675 uint32_t minor;
4676 uint32_t fix;
4677
4678 int rc;
4679
4680 // Kernel version is unknown if
4681 // verification below fails.
4682 _os_version = 0x01000000;
4683
4684 rc = uname(&_uname);
4685 if (rc != -1) {
4686
4687 rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix);
4688 if (rc == 3) {
4689
4690 if (major < 256 && minor < 256 && fix < 256) {
4691 // Kernel version format is as expected,
4692 // set it overriding unknown state.
4693 _os_version = (major << 16) |
4694 (minor << 8 ) |
4695 (fix << 0 ) ;
4696 }
4697 }
4698 }
4699 }
4700
4701 uint32_t os::Linux::os_version() {
4702 assert(_os_version != 0, "not initialized");
4703 return _os_version & 0x00FFFFFF;
4704 }
4705
4706 bool os::Linux::os_version_is_known() {
4707 assert(_os_version != 0, "not initialized");
4708 return _os_version & 0x01000000 ? false : true;
4709 }
4710
4711 /////
4712 // glibc on Linux platform uses non-documented flag
4713 // to indicate, that some special sort of signal
4714 // trampoline is used.
4715 // We will never set this flag, and we should
4716 // ignore this flag in our diagnostic
4717 #ifdef SIGNIFICANT_SIGNAL_MASK
4718 #undef SIGNIFICANT_SIGNAL_MASK
4719 #endif
4720 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
4721
4722 static const char* get_signal_handler_name(address handler,
4723 char* buf, int buflen) {
4724 int offset = 0;
4725 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
4726 if (found) {
4727 // skip directory names
4728 const char *p1, *p2;
4729 p1 = buf;
4730 size_t len = strlen(os::file_separator());
4731 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
4732 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
4733 } else {
4734 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
4735 }
4736 return buf;
4737 }
4738
4739 static void print_signal_handler(outputStream* st, int sig,
4740 char* buf, size_t buflen) {
4741 struct sigaction sa;
4742
4743 sigaction(sig, NULL, &sa);
4744
4745 // See comment for SIGNIFICANT_SIGNAL_MASK define
4746 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4747
4748 st->print("%s: ", os::exception_name(sig, buf, buflen));
4749
4750 address handler = (sa.sa_flags & SA_SIGINFO)
4751 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
4752 : CAST_FROM_FN_PTR(address, sa.sa_handler);
4753
4754 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
4755 st->print("SIG_DFL");
4756 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
4757 st->print("SIG_IGN");
4758 } else {
4759 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
4760 }
4761
4762 st->print(", sa_mask[0]=");
4763 os::Posix::print_signal_set_short(st, &sa.sa_mask);
4764
4765 address rh = VMError::get_resetted_sighandler(sig);
4766 // May be, handler was resetted by VMError?
4767 if (rh != NULL) {
4768 handler = rh;
4769 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
4770 }
4771
4772 st->print(", sa_flags=");
4773 os::Posix::print_sa_flags(st, sa.sa_flags);
4774
4775 // Check: is it our handler?
4776 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
4777 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
4778 // It is our signal handler
4779 // check for flags, reset system-used one!
4780 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) {
4781 st->print(
4782 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
4783 os::Linux::get_our_sigflags(sig));
4784 }
4785 }
4786 st->cr();
4787 }
4788
4789
4790 #define DO_SIGNAL_CHECK(sig) \
4791 do { \
4792 if (!sigismember(&check_signal_done, sig)) { \
4793 os::Linux::check_signal_handler(sig); \
4794 } \
4795 } while (0)
4796
4797 // This method is a periodic task to check for misbehaving JNI applications
4798 // under CheckJNI, we can add any periodic checks here
4799
4800 void os::run_periodic_checks() {
4801 if (check_signals == false) return;
4802
4803 // SEGV and BUS if overridden could potentially prevent
4804 // generation of hs*.log in the event of a crash, debugging
4805 // such a case can be very challenging, so we absolutely
4806 // check the following for a good measure:
4807 DO_SIGNAL_CHECK(SIGSEGV);
4808 DO_SIGNAL_CHECK(SIGILL);
4809 DO_SIGNAL_CHECK(SIGFPE);
4810 DO_SIGNAL_CHECK(SIGBUS);
4811 DO_SIGNAL_CHECK(SIGPIPE);
4812 DO_SIGNAL_CHECK(SIGXFSZ);
4813 #if defined(PPC64)
4814 DO_SIGNAL_CHECK(SIGTRAP);
4815 #endif
4816
4817 // ReduceSignalUsage allows the user to override these handlers
4818 // see comments at the very top and jvm_md.h
4819 if (!ReduceSignalUsage) {
4820 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
4821 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
4822 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
4823 DO_SIGNAL_CHECK(BREAK_SIGNAL);
4824 }
4825
4826 DO_SIGNAL_CHECK(SR_signum);
4827 }
4828
4829 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
4830
4831 static os_sigaction_t os_sigaction = NULL;
4832
4833 void os::Linux::check_signal_handler(int sig) {
4834 char buf[O_BUFLEN];
4835 address jvmHandler = NULL;
4836
4837
4838 struct sigaction act;
4839 if (os_sigaction == NULL) {
4840 // only trust the default sigaction, in case it has been interposed
4841 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
4842 if (os_sigaction == NULL) return;
4843 }
4844
4845 os_sigaction(sig, (struct sigaction*)NULL, &act);
4846
4847
4848 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4849
4850 address thisHandler = (act.sa_flags & SA_SIGINFO)
4851 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
4852 : CAST_FROM_FN_PTR(address, act.sa_handler);
4853
4854
4855 switch (sig) {
4856 case SIGSEGV:
4857 case SIGBUS:
4858 case SIGFPE:
4859 case SIGPIPE:
4860 case SIGILL:
4861 case SIGXFSZ:
4862 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
4863 break;
4864
4865 case SHUTDOWN1_SIGNAL:
4866 case SHUTDOWN2_SIGNAL:
4867 case SHUTDOWN3_SIGNAL:
4868 case BREAK_SIGNAL:
4869 jvmHandler = (address)user_handler();
4870 break;
4871
4872 default:
4873 if (sig == SR_signum) {
4874 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
4875 } else {
4876 return;
4877 }
4878 break;
4879 }
4880
4881 if (thisHandler != jvmHandler) {
4882 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
4883 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
4884 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
4885 // No need to check this sig any longer
4886 sigaddset(&check_signal_done, sig);
4887 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
4888 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
4889 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
4890 exception_name(sig, buf, O_BUFLEN));
4891 }
4892 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) {
4893 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
4894 tty->print("expected:");
4895 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig));
4896 tty->cr();
4897 tty->print(" found:");
4898 os::Posix::print_sa_flags(tty, act.sa_flags);
4899 tty->cr();
4900 // No need to check this sig any longer
4901 sigaddset(&check_signal_done, sig);
4902 }
4903
4904 // Dump all the signal
4905 if (sigismember(&check_signal_done, sig)) {
4906 print_signal_handlers(tty, buf, O_BUFLEN);
4907 }
4908 }
4909
4910 extern void report_error(char* file_name, int line_no, char* title,
4911 char* format, ...);
4912
4913 // this is called _before_ most of the global arguments have been parsed
4914 void os::init(void) {
4915 char dummy; // used to get a guess on initial stack address
4916
4917 clock_tics_per_sec = sysconf(_SC_CLK_TCK);
4918
4919 init_random(1234567);
4920
4921 Linux::set_page_size(sysconf(_SC_PAGESIZE));
4922 if (Linux::page_size() == -1) {
4923 fatal("os_linux.cpp: os::init: sysconf failed (%s)",
4924 os::strerror(errno));
4925 }
4926 init_page_sizes((size_t) Linux::page_size());
4927
4928 Linux::initialize_system_info();
4929
4930 Linux::initialize_os_info();
4931
4932 // _main_thread points to the thread that created/loaded the JVM.
4933 Linux::_main_thread = pthread_self();
4934
4935 // retrieve entry point for pthread_setname_np
4936 Linux::_pthread_setname_np =
4937 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np");
4938
4939 os::Posix::init();
4940
4941 initial_time_count = javaTimeNanos();
4942
4943 // Always warn if no monotonic clock available
4944 if (!os::Posix::supports_monotonic_clock()) {
4945 warning("No monotonic clock was available - timed services may " \
4946 "be adversely affected if the time-of-day clock changes");
4947 }
4948 }
4949
4950 // To install functions for atexit system call
4951 extern "C" {
4952 static void perfMemory_exit_helper() {
4953 perfMemory_exit();
4954 }
4955 }
4956
4957 void os::pd_init_container_support() {
4958 OSContainer::init();
4959 }
4960
4961 // this is called _after_ the global arguments have been parsed
4962 jint os::init_2(void) {
4963
4964 // This could be set after os::Posix::init() but all platforms
4965 // have to set it the same so we have to mirror Solaris.
4966 DEBUG_ONLY(os::set_mutex_init_done();)
4967
4968 os::Posix::init_2();
4969
4970 Linux::fast_thread_clock_init();
4971
4972 // initialize suspend/resume support - must do this before signal_sets_init()
4973 if (SR_initialize() != 0) {
4974 perror("SR_initialize failed");
4975 return JNI_ERR;
4976 }
4977
4978 Linux::signal_sets_init();
4979 Linux::install_signal_handlers();
4980 // Initialize data for jdk.internal.misc.Signal
4981 if (!ReduceSignalUsage) {
4982 jdk_misc_signal_init();
4983 }
4984
4985 // Check and sets minimum stack sizes against command line options
4986 if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
4987 return JNI_ERR;
4988 }
4989
4990 suppress_primordial_thread_resolution = Arguments::created_by_java_launcher();
4991 if (!suppress_primordial_thread_resolution) {
4992 Linux::capture_initial_stack(JavaThread::stack_size_at_create());
4993 }
4994
4995 #if defined(IA32)
4996 workaround_expand_exec_shield_cs_limit();
4997 #endif
4998
4999 Linux::libpthread_init();
5000 Linux::sched_getcpu_init();
5001 log_info(os)("HotSpot is running with %s, %s",
5002 Linux::glibc_version(), Linux::libpthread_version());
5003
5004 if (UseNUMA) {
5005 if (!Linux::libnuma_init()) {
5006 UseNUMA = false;
5007 } else {
5008 if ((Linux::numa_max_node() < 1) || Linux::isbound_to_single_node()) {
5009 // If there's only one node (they start from 0) or if the process
5010 // is bound explicitly to a single node using membind, disable NUMA.
5011 UseNUMA = false;
5012 }
5013 }
5014
5015 if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) {
5016 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way
5017 // we can make the adaptive lgrp chunk resizing work. If the user specified both
5018 // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn
5019 // and disable adaptive resizing.
5020 if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) {
5021 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, "
5022 "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)");
5023 UseAdaptiveSizePolicy = false;
5024 UseAdaptiveNUMAChunkSizing = false;
5025 }
5026 }
5027
5028 if (!UseNUMA && ForceNUMA) {
5029 UseNUMA = true;
5030 }
5031 }
5032
5033 if (MaxFDLimit) {
5034 // set the number of file descriptors to max. print out error
5035 // if getrlimit/setrlimit fails but continue regardless.
5036 struct rlimit nbr_files;
5037 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
5038 if (status != 0) {
5039 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
5040 } else {
5041 nbr_files.rlim_cur = nbr_files.rlim_max;
5042 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
5043 if (status != 0) {
5044 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
5045 }
5046 }
5047 }
5048
5049 // Initialize lock used to serialize thread creation (see os::create_thread)
5050 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false));
5051
5052 // at-exit methods are called in the reverse order of their registration.
5053 // atexit functions are called on return from main or as a result of a
5054 // call to exit(3C). There can be only 32 of these functions registered
5055 // and atexit() does not set errno.
5056
5057 if (PerfAllowAtExitRegistration) {
5058 // only register atexit functions if PerfAllowAtExitRegistration is set.
5059 // atexit functions can be delayed until process exit time, which
5060 // can be problematic for embedded VM situations. Embedded VMs should
5061 // call DestroyJavaVM() to assure that VM resources are released.
5062
5063 // note: perfMemory_exit_helper atexit function may be removed in
5064 // the future if the appropriate cleanup code can be added to the
5065 // VM_Exit VMOperation's doit method.
5066 if (atexit(perfMemory_exit_helper) != 0) {
5067 warning("os::init_2 atexit(perfMemory_exit_helper) failed");
5068 }
5069 }
5070
5071 // initialize thread priority policy
5072 prio_init();
5073
5074 if (!FLAG_IS_DEFAULT(AllocateHeapAt)) {
5075 set_coredump_filter(false /*largepages*/, true /*dax_shared*/);
5076 }
5077 return JNI_OK;
5078 }
5079
5080 // Mark the polling page as unreadable
5081 void os::make_polling_page_unreadable(void) {
5082 if (!guard_memory((char*)_polling_page, Linux::page_size())) {
5083 fatal("Could not disable polling page");
5084 }
5085 }
5086
5087 // Mark the polling page as readable
5088 void os::make_polling_page_readable(void) {
5089 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) {
5090 fatal("Could not enable polling page");
5091 }
5092 }
5093
5094 // older glibc versions don't have this macro (which expands to
5095 // an optimized bit-counting function) so we have to roll our own
5096 #ifndef CPU_COUNT
5097
5098 static int _cpu_count(const cpu_set_t* cpus) {
5099 int count = 0;
5100 // only look up to the number of configured processors
5101 for (int i = 0; i < os::processor_count(); i++) {
5102 if (CPU_ISSET(i, cpus)) {
5103 count++;
5104 }
5105 }
5106 return count;
5107 }
5108
5109 #define CPU_COUNT(cpus) _cpu_count(cpus)
5110
5111 #endif // CPU_COUNT
5112
5113 // Get the current number of available processors for this process.
5114 // This value can change at any time during a process's lifetime.
5115 // sched_getaffinity gives an accurate answer as it accounts for cpusets.
5116 // If it appears there may be more than 1024 processors then we do a
5117 // dynamic check - see 6515172 for details.
5118 // If anything goes wrong we fallback to returning the number of online
5119 // processors - which can be greater than the number available to the process.
5120 int os::Linux::active_processor_count() {
5121 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors
5122 cpu_set_t* cpus_p = &cpus;
5123 int cpus_size = sizeof(cpu_set_t);
5124
5125 int configured_cpus = os::processor_count(); // upper bound on available cpus
5126 int cpu_count = 0;
5127
5128 // old build platforms may not support dynamic cpu sets
5129 #ifdef CPU_ALLOC
5130
5131 // To enable easy testing of the dynamic path on different platforms we
5132 // introduce a diagnostic flag: UseCpuAllocPath
5133 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) {
5134 // kernel may use a mask bigger than cpu_set_t
5135 log_trace(os)("active_processor_count: using dynamic path %s"
5136 "- configured processors: %d",
5137 UseCpuAllocPath ? "(forced) " : "",
5138 configured_cpus);
5139 cpus_p = CPU_ALLOC(configured_cpus);
5140 if (cpus_p != NULL) {
5141 cpus_size = CPU_ALLOC_SIZE(configured_cpus);
5142 // zero it just to be safe
5143 CPU_ZERO_S(cpus_size, cpus_p);
5144 }
5145 else {
5146 // failed to allocate so fallback to online cpus
5147 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
5148 log_trace(os)("active_processor_count: "
5149 "CPU_ALLOC failed (%s) - using "
5150 "online processor count: %d",
5151 os::strerror(errno), online_cpus);
5152 return online_cpus;
5153 }
5154 }
5155 else {
5156 log_trace(os)("active_processor_count: using static path - configured processors: %d",
5157 configured_cpus);
5158 }
5159 #else // CPU_ALLOC
5160 // these stubs won't be executed
5161 #define CPU_COUNT_S(size, cpus) -1
5162 #define CPU_FREE(cpus)
5163
5164 log_trace(os)("active_processor_count: only static path available - configured processors: %d",
5165 configured_cpus);
5166 #endif // CPU_ALLOC
5167
5168 // pid 0 means the current thread - which we have to assume represents the process
5169 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) {
5170 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5171 cpu_count = CPU_COUNT_S(cpus_size, cpus_p);
5172 }
5173 else {
5174 cpu_count = CPU_COUNT(cpus_p);
5175 }
5176 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count);
5177 }
5178 else {
5179 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN);
5180 warning("sched_getaffinity failed (%s)- using online processor count (%d) "
5181 "which may exceed available processors", os::strerror(errno), cpu_count);
5182 }
5183
5184 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5185 CPU_FREE(cpus_p);
5186 }
5187
5188 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check");
5189 return cpu_count;
5190 }
5191
5192 // Determine the active processor count from one of
5193 // three different sources:
5194 //
5195 // 1. User option -XX:ActiveProcessorCount
5196 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN)
5197 // 3. extracted from cgroup cpu subsystem (shares and quotas)
5198 //
5199 // Option 1, if specified, will always override.
5200 // If the cgroup subsystem is active and configured, we
5201 // will return the min of the cgroup and option 2 results.
5202 // This is required since tools, such as numactl, that
5203 // alter cpu affinity do not update cgroup subsystem
5204 // cpuset configuration files.
5205 int os::active_processor_count() {
5206 // User has overridden the number of active processors
5207 if (ActiveProcessorCount > 0) {
5208 log_trace(os)("active_processor_count: "
5209 "active processor count set by user : %d",
5210 ActiveProcessorCount);
5211 return ActiveProcessorCount;
5212 }
5213
5214 int active_cpus;
5215 if (OSContainer::is_containerized()) {
5216 active_cpus = OSContainer::active_processor_count();
5217 log_trace(os)("active_processor_count: determined by OSContainer: %d",
5218 active_cpus);
5219 } else {
5220 active_cpus = os::Linux::active_processor_count();
5221 }
5222
5223 return active_cpus;
5224 }
5225
5226 uint os::processor_id() {
5227 const int id = Linux::sched_getcpu();
5228 assert(id >= 0 && id < _processor_count, "Invalid processor id");
5229 return (uint)id;
5230 }
5231
5232 void os::set_native_thread_name(const char *name) {
5233 if (Linux::_pthread_setname_np) {
5234 char buf [16]; // according to glibc manpage, 16 chars incl. '/0'
5235 snprintf(buf, sizeof(buf), "%s", name);
5236 buf[sizeof(buf) - 1] = '\0';
5237 const int rc = Linux::_pthread_setname_np(pthread_self(), buf);
5238 // ERANGE should not happen; all other errors should just be ignored.
5239 assert(rc != ERANGE, "pthread_setname_np failed");
5240 }
5241 }
5242
5243 bool os::distribute_processes(uint length, uint* distribution) {
5244 // Not yet implemented.
5245 return false;
5246 }
5247
5248 bool os::bind_to_processor(uint processor_id) {
5249 // Not yet implemented.
5250 return false;
5251 }
5252
5253 ///
5254
5255 void os::SuspendedThreadTask::internal_do_task() {
5256 if (do_suspend(_thread->osthread())) {
5257 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
5258 do_task(context);
5259 do_resume(_thread->osthread());
5260 }
5261 }
5262
5263 ////////////////////////////////////////////////////////////////////////////////
5264 // debug support
5265
5266 bool os::find(address addr, outputStream* st) {
5267 Dl_info dlinfo;
5268 memset(&dlinfo, 0, sizeof(dlinfo));
5269 if (dladdr(addr, &dlinfo) != 0) {
5270 st->print(PTR_FORMAT ": ", p2i(addr));
5271 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
5272 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname,
5273 p2i(addr) - p2i(dlinfo.dli_saddr));
5274 } else if (dlinfo.dli_fbase != NULL) {
5275 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase));
5276 } else {
5277 st->print("<absolute address>");
5278 }
5279 if (dlinfo.dli_fname != NULL) {
5280 st->print(" in %s", dlinfo.dli_fname);
5281 }
5282 if (dlinfo.dli_fbase != NULL) {
5283 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase));
5284 }
5285 st->cr();
5286
5287 if (Verbose) {
5288 // decode some bytes around the PC
5289 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
5290 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
5291 address lowest = (address) dlinfo.dli_sname;
5292 if (!lowest) lowest = (address) dlinfo.dli_fbase;
5293 if (begin < lowest) begin = lowest;
5294 Dl_info dlinfo2;
5295 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
5296 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
5297 end = (address) dlinfo2.dli_saddr;
5298 }
5299 Disassembler::decode(begin, end, st);
5300 }
5301 return true;
5302 }
5303 return false;
5304 }
5305
5306 ////////////////////////////////////////////////////////////////////////////////
5307 // misc
5308
5309 // This does not do anything on Linux. This is basically a hook for being
5310 // able to use structured exception handling (thread-local exception filters)
5311 // on, e.g., Win32.
5312 void
5313 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
5314 JavaCallArguments* args, Thread* thread) {
5315 f(value, method, args, thread);
5316 }
5317
5318 void os::print_statistics() {
5319 }
5320
5321 bool os::message_box(const char* title, const char* message) {
5322 int i;
5323 fdStream err(defaultStream::error_fd());
5324 for (i = 0; i < 78; i++) err.print_raw("=");
5325 err.cr();
5326 err.print_raw_cr(title);
5327 for (i = 0; i < 78; i++) err.print_raw("-");
5328 err.cr();
5329 err.print_raw_cr(message);
5330 for (i = 0; i < 78; i++) err.print_raw("=");
5331 err.cr();
5332
5333 char buf[16];
5334 // Prevent process from exiting upon "read error" without consuming all CPU
5335 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
5336
5337 return buf[0] == 'y' || buf[0] == 'Y';
5338 }
5339
5340 // Is a (classpath) directory empty?
5341 bool os::dir_is_empty(const char* path) {
5342 DIR *dir = NULL;
5343 struct dirent *ptr;
5344
5345 dir = opendir(path);
5346 if (dir == NULL) return true;
5347
5348 // Scan the directory
5349 bool result = true;
5350 while (result && (ptr = readdir(dir)) != NULL) {
5351 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
5352 result = false;
5353 }
5354 }
5355 closedir(dir);
5356 return result;
5357 }
5358
5359 // This code originates from JDK's sysOpen and open64_w
5360 // from src/solaris/hpi/src/system_md.c
5361
5362 int os::open(const char *path, int oflag, int mode) {
5363 if (strlen(path) > MAX_PATH - 1) {
5364 errno = ENAMETOOLONG;
5365 return -1;
5366 }
5367
5368 // All file descriptors that are opened in the Java process and not
5369 // specifically destined for a subprocess should have the close-on-exec
5370 // flag set. If we don't set it, then careless 3rd party native code
5371 // might fork and exec without closing all appropriate file descriptors
5372 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in
5373 // turn might:
5374 //
5375 // - cause end-of-file to fail to be detected on some file
5376 // descriptors, resulting in mysterious hangs, or
5377 //
5378 // - might cause an fopen in the subprocess to fail on a system
5379 // suffering from bug 1085341.
5380 //
5381 // (Yes, the default setting of the close-on-exec flag is a Unix
5382 // design flaw)
5383 //
5384 // See:
5385 // 1085341: 32-bit stdio routines should support file descriptors >255
5386 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
5387 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
5388 //
5389 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open().
5390 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor
5391 // because it saves a system call and removes a small window where the flag
5392 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored
5393 // and we fall back to using FD_CLOEXEC (see below).
5394 #ifdef O_CLOEXEC
5395 oflag |= O_CLOEXEC;
5396 #endif
5397
5398 int fd = ::open64(path, oflag, mode);
5399 if (fd == -1) return -1;
5400
5401 //If the open succeeded, the file might still be a directory
5402 {
5403 struct stat64 buf64;
5404 int ret = ::fstat64(fd, &buf64);
5405 int st_mode = buf64.st_mode;
5406
5407 if (ret != -1) {
5408 if ((st_mode & S_IFMT) == S_IFDIR) {
5409 errno = EISDIR;
5410 ::close(fd);
5411 return -1;
5412 }
5413 } else {
5414 ::close(fd);
5415 return -1;
5416 }
5417 }
5418
5419 #ifdef FD_CLOEXEC
5420 // Validate that the use of the O_CLOEXEC flag on open above worked.
5421 // With recent kernels, we will perform this check exactly once.
5422 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
5423 if (!O_CLOEXEC_is_known_to_work) {
5424 int flags = ::fcntl(fd, F_GETFD);
5425 if (flags != -1) {
5426 if ((flags & FD_CLOEXEC) != 0)
5427 O_CLOEXEC_is_known_to_work = 1;
5428 else
5429 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
5430 }
5431 }
5432 #endif
5433
5434 return fd;
5435 }
5436
5437
5438 // create binary file, rewriting existing file if required
5439 int os::create_binary_file(const char* path, bool rewrite_existing) {
5440 int oflags = O_WRONLY | O_CREAT;
5441 if (!rewrite_existing) {
5442 oflags |= O_EXCL;
5443 }
5444 return ::open64(path, oflags, S_IREAD | S_IWRITE);
5445 }
5446
5447 // return current position of file pointer
5448 jlong os::current_file_offset(int fd) {
5449 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
5450 }
5451
5452 // move file pointer to the specified offset
5453 jlong os::seek_to_file_offset(int fd, jlong offset) {
5454 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
5455 }
5456
5457 // This code originates from JDK's sysAvailable
5458 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
5459
5460 int os::available(int fd, jlong *bytes) {
5461 jlong cur, end;
5462 int mode;
5463 struct stat64 buf64;
5464
5465 if (::fstat64(fd, &buf64) >= 0) {
5466 mode = buf64.st_mode;
5467 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
5468 int n;
5469 if (::ioctl(fd, FIONREAD, &n) >= 0) {
5470 *bytes = n;
5471 return 1;
5472 }
5473 }
5474 }
5475 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
5476 return 0;
5477 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
5478 return 0;
5479 } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
5480 return 0;
5481 }
5482 *bytes = end - cur;
5483 return 1;
5484 }
5485
5486 // Map a block of memory.
5487 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
5488 char *addr, size_t bytes, bool read_only,
5489 bool allow_exec) {
5490 int prot;
5491 int flags = MAP_PRIVATE;
5492
5493 if (read_only) {
5494 prot = PROT_READ;
5495 } else {
5496 prot = PROT_READ | PROT_WRITE;
5497 }
5498
5499 if (allow_exec) {
5500 prot |= PROT_EXEC;
5501 }
5502
5503 if (addr != NULL) {
5504 flags |= MAP_FIXED;
5505 }
5506
5507 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
5508 fd, file_offset);
5509 if (mapped_address == MAP_FAILED) {
5510 return NULL;
5511 }
5512 return mapped_address;
5513 }
5514
5515
5516 // Remap a block of memory.
5517 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
5518 char *addr, size_t bytes, bool read_only,
5519 bool allow_exec) {
5520 // same as map_memory() on this OS
5521 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
5522 allow_exec);
5523 }
5524
5525
5526 // Unmap a block of memory.
5527 bool os::pd_unmap_memory(char* addr, size_t bytes) {
5528 return munmap(addr, bytes) == 0;
5529 }
5530
5531 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time);
5532
5533 static jlong fast_cpu_time(Thread *thread) {
5534 clockid_t clockid;
5535 int rc = os::Linux::pthread_getcpuclockid(thread->osthread()->pthread_id(),
5536 &clockid);
5537 if (rc == 0) {
5538 return os::Linux::fast_thread_cpu_time(clockid);
5539 } else {
5540 // It's possible to encounter a terminated native thread that failed
5541 // to detach itself from the VM - which should result in ESRCH.
5542 assert_status(rc == ESRCH, rc, "pthread_getcpuclockid failed");
5543 return -1;
5544 }
5545 }
5546
5547 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
5548 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
5549 // of a thread.
5550 //
5551 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
5552 // the fast estimate available on the platform.
5553
5554 jlong os::current_thread_cpu_time() {
5555 if (os::Linux::supports_fast_thread_cpu_time()) {
5556 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5557 } else {
5558 // return user + sys since the cost is the same
5559 return slow_thread_cpu_time(Thread::current(), true /* user + sys */);
5560 }
5561 }
5562
5563 jlong os::thread_cpu_time(Thread* thread) {
5564 // consistent with what current_thread_cpu_time() returns
5565 if (os::Linux::supports_fast_thread_cpu_time()) {
5566 return fast_cpu_time(thread);
5567 } else {
5568 return slow_thread_cpu_time(thread, true /* user + sys */);
5569 }
5570 }
5571
5572 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
5573 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5574 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5575 } else {
5576 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time);
5577 }
5578 }
5579
5580 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5581 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5582 return fast_cpu_time(thread);
5583 } else {
5584 return slow_thread_cpu_time(thread, user_sys_cpu_time);
5585 }
5586 }
5587
5588 // -1 on error.
5589 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5590 pid_t tid = thread->osthread()->thread_id();
5591 char *s;
5592 char stat[2048];
5593 int statlen;
5594 char proc_name[64];
5595 int count;
5596 long sys_time, user_time;
5597 char cdummy;
5598 int idummy;
5599 long ldummy;
5600 FILE *fp;
5601
5602 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid);
5603 fp = fopen(proc_name, "r");
5604 if (fp == NULL) return -1;
5605 statlen = fread(stat, 1, 2047, fp);
5606 stat[statlen] = '\0';
5607 fclose(fp);
5608
5609 // Skip pid and the command string. Note that we could be dealing with
5610 // weird command names, e.g. user could decide to rename java launcher
5611 // to "java 1.4.2 :)", then the stat file would look like
5612 // 1234 (java 1.4.2 :)) R ... ...
5613 // We don't really need to know the command string, just find the last
5614 // occurrence of ")" and then start parsing from there. See bug 4726580.
5615 s = strrchr(stat, ')');
5616 if (s == NULL) return -1;
5617
5618 // Skip blank chars
5619 do { s++; } while (s && isspace(*s));
5620
5621 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu",
5622 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy,
5623 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy,
5624 &user_time, &sys_time);
5625 if (count != 13) return -1;
5626 if (user_sys_cpu_time) {
5627 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
5628 } else {
5629 return (jlong)user_time * (1000000000 / clock_tics_per_sec);
5630 }
5631 }
5632
5633 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5634 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5635 info_ptr->may_skip_backward = false; // elapsed time not wall time
5636 info_ptr->may_skip_forward = false; // elapsed time not wall time
5637 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5638 }
5639
5640 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5641 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5642 info_ptr->may_skip_backward = false; // elapsed time not wall time
5643 info_ptr->may_skip_forward = false; // elapsed time not wall time
5644 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5645 }
5646
5647 bool os::is_thread_cpu_time_supported() {
5648 return true;
5649 }
5650
5651 // System loadavg support. Returns -1 if load average cannot be obtained.
5652 // Linux doesn't yet have a (official) notion of processor sets,
5653 // so just return the system wide load average.
5654 int os::loadavg(double loadavg[], int nelem) {
5655 return ::getloadavg(loadavg, nelem);
5656 }
5657
5658 void os::pause() {
5659 char filename[MAX_PATH];
5660 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
5661 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
5662 } else {
5663 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
5664 }
5665
5666 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
5667 if (fd != -1) {
5668 struct stat buf;
5669 ::close(fd);
5670 while (::stat(filename, &buf) == 0) {
5671 (void)::poll(NULL, 0, 100);
5672 }
5673 } else {
5674 jio_fprintf(stderr,
5675 "Could not open pause file '%s', continuing immediately.\n", filename);
5676 }
5677 }
5678
5679 extern char** environ;
5680
5681 // Run the specified command in a separate process. Return its exit value,
5682 // or -1 on failure (e.g. can't fork a new process).
5683 // Unlike system(), this function can be called from signal handler. It
5684 // doesn't block SIGINT et al.
5685 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
5686 const char * argv[4] = {"sh", "-c", cmd, NULL};
5687
5688 pid_t pid ;
5689
5690 if (use_vfork_if_available) {
5691 pid = vfork();
5692 } else {
5693 pid = fork();
5694 }
5695
5696 if (pid < 0) {
5697 // fork failed
5698 return -1;
5699
5700 } else if (pid == 0) {
5701 // child process
5702
5703 execve("/bin/sh", (char* const*)argv, environ);
5704
5705 // execve failed
5706 _exit(-1);
5707
5708 } else {
5709 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
5710 // care about the actual exit code, for now.
5711
5712 int status;
5713
5714 // Wait for the child process to exit. This returns immediately if
5715 // the child has already exited. */
5716 while (waitpid(pid, &status, 0) < 0) {
5717 switch (errno) {
5718 case ECHILD: return 0;
5719 case EINTR: break;
5720 default: return -1;
5721 }
5722 }
5723
5724 if (WIFEXITED(status)) {
5725 // The child exited normally; get its exit code.
5726 return WEXITSTATUS(status);
5727 } else if (WIFSIGNALED(status)) {
5728 // The child exited because of a signal
5729 // The best value to return is 0x80 + signal number,
5730 // because that is what all Unix shells do, and because
5731 // it allows callers to distinguish between process exit and
5732 // process death by signal.
5733 return 0x80 + WTERMSIG(status);
5734 } else {
5735 // Unknown exit code; pass it through
5736 return status;
5737 }
5738 }
5739 }
5740
5741 // Get the default path to the core file
5742 // Returns the length of the string
5743 int os::get_core_path(char* buffer, size_t bufferSize) {
5744 /*
5745 * Max length of /proc/sys/kernel/core_pattern is 128 characters.
5746 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
5747 */
5748 const int core_pattern_len = 129;
5749 char core_pattern[core_pattern_len] = {0};
5750
5751 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY);
5752 if (core_pattern_file == -1) {
5753 return -1;
5754 }
5755
5756 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len);
5757 ::close(core_pattern_file);
5758 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') {
5759 return -1;
5760 }
5761 if (core_pattern[ret-1] == '\n') {
5762 core_pattern[ret-1] = '\0';
5763 } else {
5764 core_pattern[ret] = '\0';
5765 }
5766
5767 // Replace the %p in the core pattern with the process id. NOTE: we do this
5768 // only if the pattern doesn't start with "|", and we support only one %p in
5769 // the pattern.
5770 char *pid_pos = strstr(core_pattern, "%p");
5771 const char* tail = (pid_pos != NULL) ? (pid_pos + 2) : ""; // skip over the "%p"
5772 int written;
5773
5774 if (core_pattern[0] == '/') {
5775 if (pid_pos != NULL) {
5776 *pid_pos = '\0';
5777 written = jio_snprintf(buffer, bufferSize, "%s%d%s", core_pattern,
5778 current_process_id(), tail);
5779 } else {
5780 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern);
5781 }
5782 } else {
5783 char cwd[PATH_MAX];
5784
5785 const char* p = get_current_directory(cwd, PATH_MAX);
5786 if (p == NULL) {
5787 return -1;
5788 }
5789
5790 if (core_pattern[0] == '|') {
5791 written = jio_snprintf(buffer, bufferSize,
5792 "\"%s\" (or dumping to %s/core.%d)",
5793 &core_pattern[1], p, current_process_id());
5794 } else if (pid_pos != NULL) {
5795 *pid_pos = '\0';
5796 written = jio_snprintf(buffer, bufferSize, "%s/%s%d%s", p, core_pattern,
5797 current_process_id(), tail);
5798 } else {
5799 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern);
5800 }
5801 }
5802
5803 if (written < 0) {
5804 return -1;
5805 }
5806
5807 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) {
5808 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY);
5809
5810 if (core_uses_pid_file != -1) {
5811 char core_uses_pid = 0;
5812 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1);
5813 ::close(core_uses_pid_file);
5814
5815 if (core_uses_pid == '1') {
5816 jio_snprintf(buffer + written, bufferSize - written,
5817 ".%d", current_process_id());
5818 }
5819 }
5820 }
5821
5822 return strlen(buffer);
5823 }
5824
5825 bool os::start_debugging(char *buf, int buflen) {
5826 int len = (int)strlen(buf);
5827 char *p = &buf[len];
5828
5829 jio_snprintf(p, buflen-len,
5830 "\n\n"
5831 "Do you want to debug the problem?\n\n"
5832 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n"
5833 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
5834 "Otherwise, press RETURN to abort...",
5835 os::current_process_id(), os::current_process_id(),
5836 os::current_thread_id(), os::current_thread_id());
5837
5838 bool yes = os::message_box("Unexpected Error", buf);
5839
5840 if (yes) {
5841 // yes, user asked VM to launch debugger
5842 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d",
5843 os::current_process_id(), os::current_process_id());
5844
5845 os::fork_and_exec(buf);
5846 yes = false;
5847 }
5848 return yes;
5849 }
5850
5851
5852 // Java/Compiler thread:
5853 //
5854 // Low memory addresses
5855 // P0 +------------------------+
5856 // | |\ Java thread created by VM does not have glibc
5857 // | glibc guard page | - guard page, attached Java thread usually has
5858 // | |/ 1 glibc guard page.
5859 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
5860 // | |\
5861 // | HotSpot Guard Pages | - red, yellow and reserved pages
5862 // | |/
5863 // +------------------------+ JavaThread::stack_reserved_zone_base()
5864 // | |\
5865 // | Normal Stack | -
5866 // | |/
5867 // P2 +------------------------+ Thread::stack_base()
5868 //
5869 // Non-Java thread:
5870 //
5871 // Low memory addresses
5872 // P0 +------------------------+
5873 // | |\
5874 // | glibc guard page | - usually 1 page
5875 // | |/
5876 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
5877 // | |\
5878 // | Normal Stack | -
5879 // | |/
5880 // P2 +------------------------+ Thread::stack_base()
5881 //
5882 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size
5883 // returned from pthread_attr_getstack().
5884 // ** Due to NPTL implementation error, linux takes the glibc guard page out
5885 // of the stack size given in pthread_attr. We work around this for
5886 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.)
5887 //
5888 #ifndef ZERO
5889 static void current_stack_region(address * bottom, size_t * size) {
5890 if (os::is_primordial_thread()) {
5891 // primordial thread needs special handling because pthread_getattr_np()
5892 // may return bogus value.
5893 *bottom = os::Linux::initial_thread_stack_bottom();
5894 *size = os::Linux::initial_thread_stack_size();
5895 } else {
5896 pthread_attr_t attr;
5897
5898 int rslt = pthread_getattr_np(pthread_self(), &attr);
5899
5900 // JVM needs to know exact stack location, abort if it fails
5901 if (rslt != 0) {
5902 if (rslt == ENOMEM) {
5903 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
5904 } else {
5905 fatal("pthread_getattr_np failed with error = %d", rslt);
5906 }
5907 }
5908
5909 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
5910 fatal("Cannot locate current stack attributes!");
5911 }
5912
5913 // Work around NPTL stack guard error.
5914 size_t guard_size = 0;
5915 rslt = pthread_attr_getguardsize(&attr, &guard_size);
5916 if (rslt != 0) {
5917 fatal("pthread_attr_getguardsize failed with error = %d", rslt);
5918 }
5919 *bottom += guard_size;
5920 *size -= guard_size;
5921
5922 pthread_attr_destroy(&attr);
5923
5924 }
5925 assert(os::current_stack_pointer() >= *bottom &&
5926 os::current_stack_pointer() < *bottom + *size, "just checking");
5927 }
5928
5929 address os::current_stack_base() {
5930 address bottom;
5931 size_t size;
5932 current_stack_region(&bottom, &size);
5933 return (bottom + size);
5934 }
5935
5936 size_t os::current_stack_size() {
5937 // This stack size includes the usable stack and HotSpot guard pages
5938 // (for the threads that have Hotspot guard pages).
5939 address bottom;
5940 size_t size;
5941 current_stack_region(&bottom, &size);
5942 return size;
5943 }
5944 #endif
5945
5946 static inline struct timespec get_mtime(const char* filename) {
5947 struct stat st;
5948 int ret = os::stat(filename, &st);
5949 assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
5950 return st.st_mtim;
5951 }
5952
5953 int os::compare_file_modified_times(const char* file1, const char* file2) {
5954 struct timespec filetime1 = get_mtime(file1);
5955 struct timespec filetime2 = get_mtime(file2);
5956 int diff = filetime1.tv_sec - filetime2.tv_sec;
5957 if (diff == 0) {
5958 return filetime1.tv_nsec - filetime2.tv_nsec;
5959 }
5960 return diff;
5961 }
5962
5963 /////////////// Unit tests ///////////////
5964
5965 #ifndef PRODUCT
5966
5967 class TestReserveMemorySpecial : AllStatic {
5968 public:
5969 static void small_page_write(void* addr, size_t size) {
5970 size_t page_size = os::vm_page_size();
5971
5972 char* end = (char*)addr + size;
5973 for (char* p = (char*)addr; p < end; p += page_size) {
5974 *p = 1;
5975 }
5976 }
5977
5978 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) {
5979 if (!UseHugeTLBFS) {
5980 return;
5981 }
5982
5983 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false);
5984
5985 if (addr != NULL) {
5986 small_page_write(addr, size);
5987
5988 os::Linux::release_memory_special_huge_tlbfs(addr, size);
5989 }
5990 }
5991
5992 static void test_reserve_memory_special_huge_tlbfs_only() {
5993 if (!UseHugeTLBFS) {
5994 return;
5995 }
5996
5997 size_t lp = os::large_page_size();
5998
5999 for (size_t size = lp; size <= lp * 10; size += lp) {
6000 test_reserve_memory_special_huge_tlbfs_only(size);
6001 }
6002 }
6003
6004 static void test_reserve_memory_special_huge_tlbfs_mixed() {
6005 size_t lp = os::large_page_size();
6006 size_t ag = os::vm_allocation_granularity();
6007
6008 // sizes to test
6009 const size_t sizes[] = {
6010 lp, lp + ag, lp + lp / 2, lp * 2,
6011 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2,
6012 lp * 10, lp * 10 + lp / 2
6013 };
6014 const int num_sizes = sizeof(sizes) / sizeof(size_t);
6015
6016 // For each size/alignment combination, we test three scenarios:
6017 // 1) with req_addr == NULL
6018 // 2) with a non-null req_addr at which we expect to successfully allocate
6019 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we
6020 // expect the allocation to either fail or to ignore req_addr
6021
6022 // Pre-allocate two areas; they shall be as large as the largest allocation
6023 // and aligned to the largest alignment we will be testing.
6024 const size_t mapping_size = sizes[num_sizes - 1] * 2;
6025 char* const mapping1 = (char*) ::mmap(NULL, mapping_size,
6026 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6027 -1, 0);
6028 assert(mapping1 != MAP_FAILED, "should work");
6029
6030 char* const mapping2 = (char*) ::mmap(NULL, mapping_size,
6031 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6032 -1, 0);
6033 assert(mapping2 != MAP_FAILED, "should work");
6034
6035 // Unmap the first mapping, but leave the second mapping intact: the first
6036 // mapping will serve as a value for a "good" req_addr (case 2). The second
6037 // mapping, still intact, as "bad" req_addr (case 3).
6038 ::munmap(mapping1, mapping_size);
6039
6040 // Case 1
6041 for (int i = 0; i < num_sizes; i++) {
6042 const size_t size = sizes[i];
6043 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6044 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false);
6045 if (p != NULL) {
6046 assert(is_aligned(p, alignment), "must be");
6047 small_page_write(p, size);
6048 os::Linux::release_memory_special_huge_tlbfs(p, size);
6049 }
6050 }
6051 }
6052
6053 // Case 2
6054 for (int i = 0; i < num_sizes; i++) {
6055 const size_t size = sizes[i];
6056 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6057 char* const req_addr = align_up(mapping1, alignment);
6058 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6059 if (p != NULL) {
6060 assert(p == req_addr, "must be");
6061 small_page_write(p, size);
6062 os::Linux::release_memory_special_huge_tlbfs(p, size);
6063 }
6064 }
6065 }
6066
6067 // Case 3
6068 for (int i = 0; i < num_sizes; i++) {
6069 const size_t size = sizes[i];
6070 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6071 char* const req_addr = align_up(mapping2, alignment);
6072 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6073 // as the area around req_addr contains already existing mappings, the API should always
6074 // return NULL (as per contract, it cannot return another address)
6075 assert(p == NULL, "must be");
6076 }
6077 }
6078
6079 ::munmap(mapping2, mapping_size);
6080
6081 }
6082
6083 static void test_reserve_memory_special_huge_tlbfs() {
6084 if (!UseHugeTLBFS) {
6085 return;
6086 }
6087
6088 test_reserve_memory_special_huge_tlbfs_only();
6089 test_reserve_memory_special_huge_tlbfs_mixed();
6090 }
6091
6092 static void test_reserve_memory_special_shm(size_t size, size_t alignment) {
6093 if (!UseSHM) {
6094 return;
6095 }
6096
6097 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false);
6098
6099 if (addr != NULL) {
6100 assert(is_aligned(addr, alignment), "Check");
6101 assert(is_aligned(addr, os::large_page_size()), "Check");
6102
6103 small_page_write(addr, size);
6104
6105 os::Linux::release_memory_special_shm(addr, size);
6106 }
6107 }
6108
6109 static void test_reserve_memory_special_shm() {
6110 size_t lp = os::large_page_size();
6111 size_t ag = os::vm_allocation_granularity();
6112
6113 for (size_t size = ag; size < lp * 3; size += ag) {
6114 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6115 test_reserve_memory_special_shm(size, alignment);
6116 }
6117 }
6118 }
6119
6120 static void test() {
6121 test_reserve_memory_special_huge_tlbfs();
6122 test_reserve_memory_special_shm();
6123 }
6124 };
6125
6126 void TestReserveMemorySpecial_test() {
6127 TestReserveMemorySpecial::test();
6128 }
6129
6130 #endif