1 /*
2 * Copyright (c) 1999, 2017, 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 "classfile/classLoader.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/vmSymbols.hpp"
29 #include "code/icBuffer.hpp"
30 #include "code/vtableStubs.hpp"
31 #include "compiler/compileBroker.hpp"
32 #include "compiler/disassembler.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "jvm_linux.h"
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.h"
44 #include "prims/jvm_misc.hpp"
45 #include "runtime/arguments.hpp"
46 #include "runtime/atomic.hpp"
47 #include "runtime/extendedPC.hpp"
48 #include "runtime/globals.hpp"
49 #include "runtime/interfaceSupport.hpp"
50 #include "runtime/init.hpp"
51 #include "runtime/java.hpp"
52 #include "runtime/javaCalls.hpp"
53 #include "runtime/mutexLocker.hpp"
54 #include "runtime/objectMonitor.hpp"
55 #include "runtime/orderAccess.inline.hpp"
56 #include "runtime/osThread.hpp"
57 #include "runtime/perfMemory.hpp"
58 #include "runtime/sharedRuntime.hpp"
59 #include "runtime/statSampler.hpp"
60 #include "runtime/stubRoutines.hpp"
61 #include "runtime/thread.inline.hpp"
62 #include "runtime/threadCritical.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 <semaphore.h>
99 # include <fcntl.h>
100 # include <string.h>
101 # include <syscall.h>
102 # include <sys/sysinfo.h>
103 # include <gnu/libc-version.h>
104 # include <sys/ipc.h>
105 # include <sys/shm.h>
106 # include <link.h>
107 # include <stdint.h>
108 # include <inttypes.h>
109 # include <sys/ioctl.h>
110
111 #ifndef _GNU_SOURCE
112 #define _GNU_SOURCE
113 #include <sched.h>
114 #undef _GNU_SOURCE
115 #else
116 #include <sched.h>
117 #endif
118
119 // if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling
120 // getrusage() is prepared to handle the associated failure.
121 #ifndef RUSAGE_THREAD
122 #define RUSAGE_THREAD (1) /* only the calling thread */
123 #endif
124
125 #define MAX_PATH (2 * K)
126
127 #define MAX_SECS 100000000
128
129 // for timer info max values which include all bits
130 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
131
132 #define LARGEPAGES_BIT (1 << 6)
133 ////////////////////////////////////////////////////////////////////////////////
134 // global variables
135 julong os::Linux::_physical_memory = 0;
136
137 address os::Linux::_initial_thread_stack_bottom = NULL;
138 uintptr_t os::Linux::_initial_thread_stack_size = 0;
139
140 int (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL;
141 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL;
142 int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL;
143 Mutex* os::Linux::_createThread_lock = NULL;
144 pthread_t os::Linux::_main_thread;
145 int os::Linux::_page_size = -1;
146 bool os::Linux::_supports_fast_thread_cpu_time = false;
147 uint32_t os::Linux::_os_version = 0;
148 const char * os::Linux::_glibc_version = NULL;
149 const char * os::Linux::_libpthread_version = NULL;
150
151 static jlong initial_time_count=0;
152
153 static int clock_tics_per_sec = 100;
154
155 // For diagnostics to print a message once. see run_periodic_checks
156 static sigset_t check_signal_done;
157 static bool check_signals = true;
158
159 // Signal number used to suspend/resume a thread
160
161 // do not use any signal number less than SIGSEGV, see 4355769
162 static int SR_signum = SIGUSR2;
163 sigset_t SR_sigset;
164
165 // utility functions
166
167 static int SR_initialize();
168
169 julong os::available_memory() {
170 return Linux::available_memory();
171 }
172
173 julong os::Linux::available_memory() {
174 // values in struct sysinfo are "unsigned long"
175 struct sysinfo si;
176 julong avail_mem;
177
178 if (OSContainer::is_containerized()) {
179 jlong mem_limit, mem_usage;
180 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) {
181 if ((mem_usage = OSContainer::memory_usage_in_bytes()) > 0) {
182 if (mem_limit > mem_usage) {
183 avail_mem = (julong)mem_limit - (julong)mem_usage;
184 } else {
185 avail_mem = 0;
186 }
187 log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem);
188 return avail_mem;
189 } else {
190 log_debug(os,container)("container memory usage call failed: " JLONG_FORMAT, mem_usage);
191 }
192 } else {
193 log_debug(os,container)("container memory unlimited or failed: " JLONG_FORMAT, mem_limit);
194 }
195 }
196
197 sysinfo(&si);
198 avail_mem = (julong)si.freeram * si.mem_unit;
199 log_trace(os)("available memory: " JULONG_FORMAT, avail_mem);
200 return avail_mem;
201 }
202
203 julong os::physical_memory() {
204 if (OSContainer::is_containerized()) {
205 jlong mem_limit;
206 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) {
207 log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit);
208 return (julong)mem_limit;
209 } else {
210 if (mem_limit == OSCONTAINER_ERROR) {
211 log_debug(os,container)("container memory limit call failed");
212 }
213 if (mem_limit == -1) {
214 log_debug(os,container)("container memory unlimited, using host value");
215 }
216 }
217 }
218
219 jlong phys_mem = Linux::physical_memory();
220 log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem);
221 return phys_mem;
222 }
223
224 // Return true if user is running as root.
225
226 bool os::have_special_privileges() {
227 static bool init = false;
228 static bool privileges = false;
229 if (!init) {
230 privileges = (getuid() != geteuid()) || (getgid() != getegid());
231 init = true;
232 }
233 return privileges;
234 }
235
236
237 #ifndef SYS_gettid
238 // i386: 224, ia64: 1105, amd64: 186, sparc 143
239 #ifdef __ia64__
240 #define SYS_gettid 1105
241 #else
242 #ifdef __i386__
243 #define SYS_gettid 224
244 #else
245 #ifdef __amd64__
246 #define SYS_gettid 186
247 #else
248 #ifdef __sparc__
249 #define SYS_gettid 143
250 #else
251 #error define gettid for the arch
252 #endif
253 #endif
254 #endif
255 #endif
256 #endif
257
258
259 // pid_t gettid()
260 //
261 // Returns the kernel thread id of the currently running thread. Kernel
262 // thread id is used to access /proc.
263 pid_t os::Linux::gettid() {
264 int rslt = syscall(SYS_gettid);
265 assert(rslt != -1, "must be."); // old linuxthreads implementation?
266 return (pid_t)rslt;
267 }
268
269 // Most versions of linux have a bug where the number of processors are
270 // determined by looking at the /proc file system. In a chroot environment,
271 // the system call returns 1. This causes the VM to act as if it is
272 // a single processor and elide locking (see is_MP() call).
273 static bool unsafe_chroot_detected = false;
274 static const char *unstable_chroot_error = "/proc file system not found.\n"
275 "Java may be unstable running multithreaded in a chroot "
276 "environment on Linux when /proc filesystem is not mounted.";
277
278 void os::Linux::initialize_system_info() {
279 set_processor_count(sysconf(_SC_NPROCESSORS_CONF));
280 if (processor_count() == 1) {
281 pid_t pid = os::Linux::gettid();
282 char fname[32];
283 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid);
284 FILE *fp = fopen(fname, "r");
285 if (fp == NULL) {
286 unsafe_chroot_detected = true;
287 } else {
288 fclose(fp);
289 }
290 }
291 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE);
292 assert(processor_count() > 0, "linux error");
293 }
294
295 void os::init_system_properties_values() {
296 // The next steps are taken in the product version:
297 //
298 // Obtain the JAVA_HOME value from the location of libjvm.so.
299 // This library should be located at:
300 // <JAVA_HOME>/lib/{client|server}/libjvm.so.
301 //
302 // If "/jre/lib/" appears at the right place in the path, then we
303 // assume libjvm.so is installed in a JDK and we use this path.
304 //
305 // Otherwise exit with message: "Could not create the Java virtual machine."
306 //
307 // The following extra steps are taken in the debugging version:
308 //
309 // If "/jre/lib/" does NOT appear at the right place in the path
310 // instead of exit check for $JAVA_HOME environment variable.
311 //
312 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
313 // then we append a fake suffix "hotspot/libjvm.so" to this path so
314 // it looks like libjvm.so is installed there
315 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
316 //
317 // Otherwise exit.
318 //
319 // Important note: if the location of libjvm.so changes this
320 // code needs to be changed accordingly.
321
322 // See ld(1):
323 // The linker uses the following search paths to locate required
324 // shared libraries:
325 // 1: ...
326 // ...
327 // 7: The default directories, normally /lib and /usr/lib.
328 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390)
329 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib"
330 #else
331 #define DEFAULT_LIBPATH "/lib:/usr/lib"
332 #endif
333
334 // Base path of extensions installed on the system.
335 #define SYS_EXT_DIR "/usr/java/packages"
336 #define EXTENSIONS_DIR "/lib/ext"
337
338 // Buffer that fits several sprintfs.
339 // Note that the space for the colon and the trailing null are provided
340 // by the nulls included by the sizeof operator.
341 const size_t bufsize =
342 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
343 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
344 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
345
346 // sysclasspath, java_home, dll_dir
347 {
348 char *pslash;
349 os::jvm_path(buf, bufsize);
350
351 // Found the full path to libjvm.so.
352 // Now cut the path to <java_home>/jre if we can.
353 pslash = strrchr(buf, '/');
354 if (pslash != NULL) {
355 *pslash = '\0'; // Get rid of /libjvm.so.
356 }
357 pslash = strrchr(buf, '/');
358 if (pslash != NULL) {
359 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
360 }
361 Arguments::set_dll_dir(buf);
362
363 if (pslash != NULL) {
364 pslash = strrchr(buf, '/');
365 if (pslash != NULL) {
366 *pslash = '\0'; // Get rid of /lib.
367 }
368 }
369 Arguments::set_java_home(buf);
370 set_boot_path('/', ':');
371 }
372
373 // Where to look for native libraries.
374 //
375 // Note: Due to a legacy implementation, most of the library path
376 // is set in the launcher. This was to accomodate linking restrictions
377 // on legacy Linux implementations (which are no longer supported).
378 // Eventually, all the library path setting will be done here.
379 //
380 // However, to prevent the proliferation of improperly built native
381 // libraries, the new path component /usr/java/packages is added here.
382 // Eventually, all the library path setting will be done here.
383 {
384 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
385 // should always exist (until the legacy problem cited above is
386 // addressed).
387 const char *v = ::getenv("LD_LIBRARY_PATH");
388 const char *v_colon = ":";
389 if (v == NULL) { v = ""; v_colon = ""; }
390 // That's +1 for the colon and +1 for the trailing '\0'.
391 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
392 strlen(v) + 1 +
393 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1,
394 mtInternal);
395 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon);
396 Arguments::set_library_path(ld_library_path);
397 FREE_C_HEAP_ARRAY(char, ld_library_path);
398 }
399
400 // Extensions directories.
401 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
402 Arguments::set_ext_dirs(buf);
403
404 FREE_C_HEAP_ARRAY(char, buf);
405
406 #undef DEFAULT_LIBPATH
407 #undef SYS_EXT_DIR
408 #undef EXTENSIONS_DIR
409 }
410
411 ////////////////////////////////////////////////////////////////////////////////
412 // breakpoint support
413
414 void os::breakpoint() {
415 BREAKPOINT;
416 }
417
418 extern "C" void breakpoint() {
419 // use debugger to set breakpoint here
420 }
421
422 ////////////////////////////////////////////////////////////////////////////////
423 // signal support
424
425 debug_only(static bool signal_sets_initialized = false);
426 static sigset_t unblocked_sigs, vm_sigs;
427
428 bool os::Linux::is_sig_ignored(int sig) {
429 struct sigaction oact;
430 sigaction(sig, (struct sigaction*)NULL, &oact);
431 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
432 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
433 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
434 return true;
435 } else {
436 return false;
437 }
438 }
439
440 void os::Linux::signal_sets_init() {
441 // Should also have an assertion stating we are still single-threaded.
442 assert(!signal_sets_initialized, "Already initialized");
443 // Fill in signals that are necessarily unblocked for all threads in
444 // the VM. Currently, we unblock the following signals:
445 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
446 // by -Xrs (=ReduceSignalUsage));
447 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
448 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
449 // the dispositions or masks wrt these signals.
450 // Programs embedding the VM that want to use the above signals for their
451 // own purposes must, at this time, use the "-Xrs" option to prevent
452 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
453 // (See bug 4345157, and other related bugs).
454 // In reality, though, unblocking these signals is really a nop, since
455 // these signals are not blocked by default.
456 sigemptyset(&unblocked_sigs);
457 sigaddset(&unblocked_sigs, SIGILL);
458 sigaddset(&unblocked_sigs, SIGSEGV);
459 sigaddset(&unblocked_sigs, SIGBUS);
460 sigaddset(&unblocked_sigs, SIGFPE);
461 #if defined(PPC64)
462 sigaddset(&unblocked_sigs, SIGTRAP);
463 #endif
464 sigaddset(&unblocked_sigs, SR_signum);
465
466 if (!ReduceSignalUsage) {
467 if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
468 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
469 }
470 if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
471 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
472 }
473 if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
474 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
475 }
476 }
477 // Fill in signals that are blocked by all but the VM thread.
478 sigemptyset(&vm_sigs);
479 if (!ReduceSignalUsage) {
480 sigaddset(&vm_sigs, BREAK_SIGNAL);
481 }
482 debug_only(signal_sets_initialized = true);
483
484 }
485
486 // These are signals that are unblocked while a thread is running Java.
487 // (For some reason, they get blocked by default.)
488 sigset_t* os::Linux::unblocked_signals() {
489 assert(signal_sets_initialized, "Not initialized");
490 return &unblocked_sigs;
491 }
492
493 // These are the signals that are blocked while a (non-VM) thread is
494 // running Java. Only the VM thread handles these signals.
495 sigset_t* os::Linux::vm_signals() {
496 assert(signal_sets_initialized, "Not initialized");
497 return &vm_sigs;
498 }
499
500 void os::Linux::hotspot_sigmask(Thread* thread) {
501
502 //Save caller's signal mask before setting VM signal mask
503 sigset_t caller_sigmask;
504 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
505
506 OSThread* osthread = thread->osthread();
507 osthread->set_caller_sigmask(caller_sigmask);
508
509 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL);
510
511 if (!ReduceSignalUsage) {
512 if (thread->is_VM_thread()) {
513 // Only the VM thread handles BREAK_SIGNAL ...
514 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
515 } else {
516 // ... all other threads block BREAK_SIGNAL
517 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
518 }
519 }
520 }
521
522 //////////////////////////////////////////////////////////////////////////////
523 // detecting pthread library
524
525 void os::Linux::libpthread_init() {
526 // Save glibc and pthread version strings.
527 #if !defined(_CS_GNU_LIBC_VERSION) || \
528 !defined(_CS_GNU_LIBPTHREAD_VERSION)
529 #error "glibc too old (< 2.3.2)"
530 #endif
531
532 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0);
533 assert(n > 0, "cannot retrieve glibc version");
534 char *str = (char *)malloc(n, mtInternal);
535 confstr(_CS_GNU_LIBC_VERSION, str, n);
536 os::Linux::set_glibc_version(str);
537
538 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
539 assert(n > 0, "cannot retrieve pthread version");
540 str = (char *)malloc(n, mtInternal);
541 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n);
542 os::Linux::set_libpthread_version(str);
543 }
544
545 /////////////////////////////////////////////////////////////////////////////
546 // thread stack expansion
547
548 // os::Linux::manually_expand_stack() takes care of expanding the thread
549 // stack. Note that this is normally not needed: pthread stacks allocate
550 // thread stack using mmap() without MAP_NORESERVE, so the stack is already
551 // committed. Therefore it is not necessary to expand the stack manually.
552 //
553 // Manually expanding the stack was historically needed on LinuxThreads
554 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays
555 // it is kept to deal with very rare corner cases:
556 //
557 // For one, user may run the VM on an own implementation of threads
558 // whose stacks are - like the old LinuxThreads - implemented using
559 // mmap(MAP_GROWSDOWN).
560 //
561 // Also, this coding may be needed if the VM is running on the primordial
562 // thread. Normally we avoid running on the primordial thread; however,
563 // user may still invoke the VM on the primordial thread.
564 //
565 // The following historical comment describes the details about running
566 // on a thread stack allocated with mmap(MAP_GROWSDOWN):
567
568
569 // Force Linux kernel to expand current thread stack. If "bottom" is close
570 // to the stack guard, caller should block all signals.
571 //
572 // MAP_GROWSDOWN:
573 // A special mmap() flag that is used to implement thread stacks. It tells
574 // kernel that the memory region should extend downwards when needed. This
575 // allows early versions of LinuxThreads to only mmap the first few pages
576 // when creating a new thread. Linux kernel will automatically expand thread
577 // stack as needed (on page faults).
578 //
579 // However, because the memory region of a MAP_GROWSDOWN stack can grow on
580 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN
581 // region, it's hard to tell if the fault is due to a legitimate stack
582 // access or because of reading/writing non-exist memory (e.g. buffer
583 // overrun). As a rule, if the fault happens below current stack pointer,
584 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the
585 // application (see Linux kernel fault.c).
586 //
587 // This Linux feature can cause SIGSEGV when VM bangs thread stack for
588 // stack overflow detection.
589 //
590 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do
591 // not use MAP_GROWSDOWN.
592 //
593 // To get around the problem and allow stack banging on Linux, we need to
594 // manually expand thread stack after receiving the SIGSEGV.
595 //
596 // There are two ways to expand thread stack to address "bottom", we used
597 // both of them in JVM before 1.5:
598 // 1. adjust stack pointer first so that it is below "bottom", and then
599 // touch "bottom"
600 // 2. mmap() the page in question
601 //
602 // Now alternate signal stack is gone, it's harder to use 2. For instance,
603 // if current sp is already near the lower end of page 101, and we need to
604 // call mmap() to map page 100, it is possible that part of the mmap() frame
605 // will be placed in page 100. When page 100 is mapped, it is zero-filled.
606 // That will destroy the mmap() frame and cause VM to crash.
607 //
608 // The following code works by adjusting sp first, then accessing the "bottom"
609 // page to force a page fault. Linux kernel will then automatically expand the
610 // stack mapping.
611 //
612 // _expand_stack_to() assumes its frame size is less than page size, which
613 // should always be true if the function is not inlined.
614
615 static void NOINLINE _expand_stack_to(address bottom) {
616 address sp;
617 size_t size;
618 volatile char *p;
619
620 // Adjust bottom to point to the largest address within the same page, it
621 // gives us a one-page buffer if alloca() allocates slightly more memory.
622 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size());
623 bottom += os::Linux::page_size() - 1;
624
625 // sp might be slightly above current stack pointer; if that's the case, we
626 // will alloca() a little more space than necessary, which is OK. Don't use
627 // os::current_stack_pointer(), as its result can be slightly below current
628 // stack pointer, causing us to not alloca enough to reach "bottom".
629 sp = (address)&sp;
630
631 if (sp > bottom) {
632 size = sp - bottom;
633 p = (volatile char *)alloca(size);
634 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?");
635 p[0] = '\0';
636 }
637 }
638
639 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) {
640 assert(t!=NULL, "just checking");
641 assert(t->osthread()->expanding_stack(), "expand should be set");
642 assert(t->stack_base() != NULL, "stack_base was not initialized");
643
644 if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) {
645 sigset_t mask_all, old_sigset;
646 sigfillset(&mask_all);
647 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset);
648 _expand_stack_to(addr);
649 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL);
650 return true;
651 }
652 return false;
653 }
654
655 //////////////////////////////////////////////////////////////////////////////
656 // create new thread
657
658 // Thread start routine for all newly created threads
659 static void *thread_native_entry(Thread *thread) {
660 // Try to randomize the cache line index of hot stack frames.
661 // This helps when threads of the same stack traces evict each other's
662 // cache lines. The threads can be either from the same JVM instance, or
663 // from different JVM instances. The benefit is especially true for
664 // processors with hyperthreading technology.
665 static int counter = 0;
666 int pid = os::current_process_id();
667 alloca(((pid ^ counter++) & 7) * 128);
668
669 thread->initialize_thread_current();
670
671 OSThread* osthread = thread->osthread();
672 Monitor* sync = osthread->startThread_lock();
673
674 osthread->set_thread_id(os::current_thread_id());
675
676 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
677 os::current_thread_id(), (uintx) pthread_self());
678
679 if (UseNUMA) {
680 int lgrp_id = os::numa_get_group_id();
681 if (lgrp_id != -1) {
682 thread->set_lgrp_id(lgrp_id);
683 }
684 }
685 // initialize signal mask for this thread
686 os::Linux::hotspot_sigmask(thread);
687
688 // initialize floating point control register
689 os::Linux::init_thread_fpu_state();
690
691 // handshaking with parent thread
692 {
693 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
694
695 // notify parent thread
696 osthread->set_state(INITIALIZED);
697 sync->notify_all();
698
699 // wait until os::start_thread()
700 while (osthread->get_state() == INITIALIZED) {
701 sync->wait(Mutex::_no_safepoint_check_flag);
702 }
703 }
704
705 // call one more level start routine
706 thread->run();
707
708 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
709 os::current_thread_id(), (uintx) pthread_self());
710
711 // If a thread has not deleted itself ("delete this") as part of its
712 // termination sequence, we have to ensure thread-local-storage is
713 // cleared before we actually terminate. No threads should ever be
714 // deleted asynchronously with respect to their termination.
715 if (Thread::current_or_null_safe() != NULL) {
716 assert(Thread::current_or_null_safe() == thread, "current thread is wrong");
717 thread->clear_thread_current();
718 }
719
720 return 0;
721 }
722
723 bool os::create_thread(Thread* thread, ThreadType thr_type,
724 size_t req_stack_size) {
725 assert(thread->osthread() == NULL, "caller responsible");
726
727 // Allocate the OSThread object
728 OSThread* osthread = new OSThread(NULL, NULL);
729 if (osthread == NULL) {
730 return false;
731 }
732
733 // set the correct thread state
734 osthread->set_thread_type(thr_type);
735
736 // Initial state is ALLOCATED but not INITIALIZED
737 osthread->set_state(ALLOCATED);
738
739 thread->set_osthread(osthread);
740
741 // init thread attributes
742 pthread_attr_t attr;
743 pthread_attr_init(&attr);
744 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
745
746 // Calculate stack size if it's not specified by caller.
747 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
748 // In the Linux NPTL pthread implementation the guard size mechanism
749 // is not implemented properly. The posix standard requires adding
750 // the size of the guard pages to the stack size, instead Linux
751 // takes the space out of 'stacksize'. Thus we adapt the requested
752 // stack_size by the size of the guard pages to mimick proper
753 // behaviour. However, be careful not to end up with a size
754 // of zero due to overflow. Don't add the guard page in that case.
755 size_t guard_size = os::Linux::default_guard_size(thr_type);
756 if (stack_size <= SIZE_MAX - guard_size) {
757 stack_size += guard_size;
758 }
759 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned");
760
761 int status = pthread_attr_setstacksize(&attr, stack_size);
762 assert_status(status == 0, status, "pthread_attr_setstacksize");
763
764 // Configure glibc guard page.
765 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type));
766
767 ThreadState state;
768
769 {
770 pthread_t tid;
771 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
772
773 char buf[64];
774 if (ret == 0) {
775 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
776 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
777 } else {
778 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
779 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
780 }
781
782 pthread_attr_destroy(&attr);
783
784 if (ret != 0) {
785 // Need to clean up stuff we've allocated so far
786 thread->set_osthread(NULL);
787 delete osthread;
788 return false;
789 }
790
791 // Store pthread info into the OSThread
792 osthread->set_pthread_id(tid);
793
794 // Wait until child thread is either initialized or aborted
795 {
796 Monitor* sync_with_child = osthread->startThread_lock();
797 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
798 while ((state = osthread->get_state()) == ALLOCATED) {
799 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
800 }
801 }
802 }
803
804 // Aborted due to thread limit being reached
805 if (state == ZOMBIE) {
806 thread->set_osthread(NULL);
807 delete osthread;
808 return false;
809 }
810
811 // The thread is returned suspended (in state INITIALIZED),
812 // and is started higher up in the call chain
813 assert(state == INITIALIZED, "race condition");
814 return true;
815 }
816
817 /////////////////////////////////////////////////////////////////////////////
818 // attach existing thread
819
820 // bootstrap the main thread
821 bool os::create_main_thread(JavaThread* thread) {
822 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread");
823 return create_attached_thread(thread);
824 }
825
826 bool os::create_attached_thread(JavaThread* thread) {
827 #ifdef ASSERT
828 thread->verify_not_published();
829 #endif
830
831 // Allocate the OSThread object
832 OSThread* osthread = new OSThread(NULL, NULL);
833
834 if (osthread == NULL) {
835 return false;
836 }
837
838 // Store pthread info into the OSThread
839 osthread->set_thread_id(os::Linux::gettid());
840 osthread->set_pthread_id(::pthread_self());
841
842 // initialize floating point control register
843 os::Linux::init_thread_fpu_state();
844
845 // Initial thread state is RUNNABLE
846 osthread->set_state(RUNNABLE);
847
848 thread->set_osthread(osthread);
849
850 if (UseNUMA) {
851 int lgrp_id = os::numa_get_group_id();
852 if (lgrp_id != -1) {
853 thread->set_lgrp_id(lgrp_id);
854 }
855 }
856
857 if (os::Linux::is_initial_thread()) {
858 // If current thread is initial thread, its stack is mapped on demand,
859 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map
860 // the entire stack region to avoid SEGV in stack banging.
861 // It is also useful to get around the heap-stack-gap problem on SuSE
862 // kernel (see 4821821 for details). We first expand stack to the top
863 // of yellow zone, then enable stack yellow zone (order is significant,
864 // enabling yellow zone first will crash JVM on SuSE Linux), so there
865 // is no gap between the last two virtual memory regions.
866
867 JavaThread *jt = (JavaThread *)thread;
868 address addr = jt->stack_reserved_zone_base();
869 assert(addr != NULL, "initialization problem?");
870 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled");
871
872 osthread->set_expanding_stack();
873 os::Linux::manually_expand_stack(jt, addr);
874 osthread->clear_expanding_stack();
875 }
876
877 // initialize signal mask for this thread
878 // and save the caller's signal mask
879 os::Linux::hotspot_sigmask(thread);
880
881 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
882 os::current_thread_id(), (uintx) pthread_self());
883
884 return true;
885 }
886
887 void os::pd_start_thread(Thread* thread) {
888 OSThread * osthread = thread->osthread();
889 assert(osthread->get_state() != INITIALIZED, "just checking");
890 Monitor* sync_with_child = osthread->startThread_lock();
891 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
892 sync_with_child->notify();
893 }
894
895 // Free Linux resources related to the OSThread
896 void os::free_thread(OSThread* osthread) {
897 assert(osthread != NULL, "osthread not set");
898
899 // We are told to free resources of the argument thread,
900 // but we can only really operate on the current thread.
901 assert(Thread::current()->osthread() == osthread,
902 "os::free_thread but not current thread");
903
904 #ifdef ASSERT
905 sigset_t current;
906 sigemptyset(¤t);
907 pthread_sigmask(SIG_SETMASK, NULL, ¤t);
908 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!");
909 #endif
910
911 // Restore caller's signal mask
912 sigset_t sigmask = osthread->caller_sigmask();
913 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
914
915 delete osthread;
916 }
917
918 //////////////////////////////////////////////////////////////////////////////
919 // initial thread
920
921 // Check if current thread is the initial thread, similar to Solaris thr_main.
922 bool os::Linux::is_initial_thread(void) {
923 char dummy;
924 // If called before init complete, thread stack bottom will be null.
925 // Can be called if fatal error occurs before initialization.
926 if (initial_thread_stack_bottom() == NULL) return false;
927 assert(initial_thread_stack_bottom() != NULL &&
928 initial_thread_stack_size() != 0,
929 "os::init did not locate initial thread's stack region");
930 if ((address)&dummy >= initial_thread_stack_bottom() &&
931 (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size()) {
932 return true;
933 } else {
934 return false;
935 }
936 }
937
938 // Find the virtual memory area that contains addr
939 static bool find_vma(address addr, address* vma_low, address* vma_high) {
940 FILE *fp = fopen("/proc/self/maps", "r");
941 if (fp) {
942 address low, high;
943 while (!feof(fp)) {
944 if (fscanf(fp, "%p-%p", &low, &high) == 2) {
945 if (low <= addr && addr < high) {
946 if (vma_low) *vma_low = low;
947 if (vma_high) *vma_high = high;
948 fclose(fp);
949 return true;
950 }
951 }
952 for (;;) {
953 int ch = fgetc(fp);
954 if (ch == EOF || ch == (int)'\n') break;
955 }
956 }
957 fclose(fp);
958 }
959 return false;
960 }
961
962 // Locate initial thread stack. This special handling of initial thread stack
963 // is needed because pthread_getattr_np() on most (all?) Linux distros returns
964 // bogus value for the primordial process thread. While the launcher has created
965 // the VM in a new thread since JDK 6, we still have to allow for the use of the
966 // JNI invocation API from a primordial thread.
967 void os::Linux::capture_initial_stack(size_t max_size) {
968
969 // max_size is either 0 (which means accept OS default for thread stacks) or
970 // a user-specified value known to be at least the minimum needed. If we
971 // are actually on the primordial thread we can make it appear that we have a
972 // smaller max_size stack by inserting the guard pages at that location. But we
973 // cannot do anything to emulate a larger stack than what has been provided by
974 // the OS or threading library. In fact if we try to use a stack greater than
975 // what is set by rlimit then we will crash the hosting process.
976
977 // Maximum stack size is the easy part, get it from RLIMIT_STACK.
978 // If this is "unlimited" then it will be a huge value.
979 struct rlimit rlim;
980 getrlimit(RLIMIT_STACK, &rlim);
981 size_t stack_size = rlim.rlim_cur;
982
983 // 6308388: a bug in ld.so will relocate its own .data section to the
984 // lower end of primordial stack; reduce ulimit -s value a little bit
985 // so we won't install guard page on ld.so's data section.
986 stack_size -= 2 * page_size();
987
988 // Try to figure out where the stack base (top) is. This is harder.
989 //
990 // When an application is started, glibc saves the initial stack pointer in
991 // a global variable "__libc_stack_end", which is then used by system
992 // libraries. __libc_stack_end should be pretty close to stack top. The
993 // variable is available since the very early days. However, because it is
994 // a private interface, it could disappear in the future.
995 //
996 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar
997 // to __libc_stack_end, it is very close to stack top, but isn't the real
998 // stack top. Note that /proc may not exist if VM is running as a chroot
999 // program, so reading /proc/<pid>/stat could fail. Also the contents of
1000 // /proc/<pid>/stat could change in the future (though unlikely).
1001 //
1002 // We try __libc_stack_end first. If that doesn't work, look for
1003 // /proc/<pid>/stat. If neither of them works, we use current stack pointer
1004 // as a hint, which should work well in most cases.
1005
1006 uintptr_t stack_start;
1007
1008 // try __libc_stack_end first
1009 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end");
1010 if (p && *p) {
1011 stack_start = *p;
1012 } else {
1013 // see if we can get the start_stack field from /proc/self/stat
1014 FILE *fp;
1015 int pid;
1016 char state;
1017 int ppid;
1018 int pgrp;
1019 int session;
1020 int nr;
1021 int tpgrp;
1022 unsigned long flags;
1023 unsigned long minflt;
1024 unsigned long cminflt;
1025 unsigned long majflt;
1026 unsigned long cmajflt;
1027 unsigned long utime;
1028 unsigned long stime;
1029 long cutime;
1030 long cstime;
1031 long prio;
1032 long nice;
1033 long junk;
1034 long it_real;
1035 uintptr_t start;
1036 uintptr_t vsize;
1037 intptr_t rss;
1038 uintptr_t rsslim;
1039 uintptr_t scodes;
1040 uintptr_t ecode;
1041 int i;
1042
1043 // Figure what the primordial thread stack base is. Code is inspired
1044 // by email from Hans Boehm. /proc/self/stat begins with current pid,
1045 // followed by command name surrounded by parentheses, state, etc.
1046 char stat[2048];
1047 int statlen;
1048
1049 fp = fopen("/proc/self/stat", "r");
1050 if (fp) {
1051 statlen = fread(stat, 1, 2047, fp);
1052 stat[statlen] = '\0';
1053 fclose(fp);
1054
1055 // Skip pid and the command string. Note that we could be dealing with
1056 // weird command names, e.g. user could decide to rename java launcher
1057 // to "java 1.4.2 :)", then the stat file would look like
1058 // 1234 (java 1.4.2 :)) R ... ...
1059 // We don't really need to know the command string, just find the last
1060 // occurrence of ")" and then start parsing from there. See bug 4726580.
1061 char * s = strrchr(stat, ')');
1062
1063 i = 0;
1064 if (s) {
1065 // Skip blank chars
1066 do { s++; } while (s && isspace(*s));
1067
1068 #define _UFM UINTX_FORMAT
1069 #define _DFM INTX_FORMAT
1070
1071 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2
1072 // 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
1073 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,
1074 &state, // 3 %c
1075 &ppid, // 4 %d
1076 &pgrp, // 5 %d
1077 &session, // 6 %d
1078 &nr, // 7 %d
1079 &tpgrp, // 8 %d
1080 &flags, // 9 %lu
1081 &minflt, // 10 %lu
1082 &cminflt, // 11 %lu
1083 &majflt, // 12 %lu
1084 &cmajflt, // 13 %lu
1085 &utime, // 14 %lu
1086 &stime, // 15 %lu
1087 &cutime, // 16 %ld
1088 &cstime, // 17 %ld
1089 &prio, // 18 %ld
1090 &nice, // 19 %ld
1091 &junk, // 20 %ld
1092 &it_real, // 21 %ld
1093 &start, // 22 UINTX_FORMAT
1094 &vsize, // 23 UINTX_FORMAT
1095 &rss, // 24 INTX_FORMAT
1096 &rsslim, // 25 UINTX_FORMAT
1097 &scodes, // 26 UINTX_FORMAT
1098 &ecode, // 27 UINTX_FORMAT
1099 &stack_start); // 28 UINTX_FORMAT
1100 }
1101
1102 #undef _UFM
1103 #undef _DFM
1104
1105 if (i != 28 - 2) {
1106 assert(false, "Bad conversion from /proc/self/stat");
1107 // product mode - assume we are the initial thread, good luck in the
1108 // embedded case.
1109 warning("Can't detect initial thread stack location - bad conversion");
1110 stack_start = (uintptr_t) &rlim;
1111 }
1112 } else {
1113 // For some reason we can't open /proc/self/stat (for example, running on
1114 // FreeBSD with a Linux emulator, or inside chroot), this should work for
1115 // most cases, so don't abort:
1116 warning("Can't detect initial thread stack location - no /proc/self/stat");
1117 stack_start = (uintptr_t) &rlim;
1118 }
1119 }
1120
1121 // Now we have a pointer (stack_start) very close to the stack top, the
1122 // next thing to do is to figure out the exact location of stack top. We
1123 // can find out the virtual memory area that contains stack_start by
1124 // reading /proc/self/maps, it should be the last vma in /proc/self/maps,
1125 // and its upper limit is the real stack top. (again, this would fail if
1126 // running inside chroot, because /proc may not exist.)
1127
1128 uintptr_t stack_top;
1129 address low, high;
1130 if (find_vma((address)stack_start, &low, &high)) {
1131 // success, "high" is the true stack top. (ignore "low", because initial
1132 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.)
1133 stack_top = (uintptr_t)high;
1134 } else {
1135 // failed, likely because /proc/self/maps does not exist
1136 warning("Can't detect initial thread stack location - find_vma failed");
1137 // best effort: stack_start is normally within a few pages below the real
1138 // stack top, use it as stack top, and reduce stack size so we won't put
1139 // guard page outside stack.
1140 stack_top = stack_start;
1141 stack_size -= 16 * page_size();
1142 }
1143
1144 // stack_top could be partially down the page so align it
1145 stack_top = align_up(stack_top, page_size());
1146
1147 // Allowed stack value is minimum of max_size and what we derived from rlimit
1148 if (max_size > 0) {
1149 _initial_thread_stack_size = MIN2(max_size, stack_size);
1150 } else {
1151 // Accept the rlimit max, but if stack is unlimited then it will be huge, so
1152 // clamp it at 8MB as we do on Solaris
1153 _initial_thread_stack_size = MIN2(stack_size, 8*M);
1154 }
1155 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size());
1156 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size;
1157
1158 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!");
1159
1160 if (log_is_enabled(Info, os, thread)) {
1161 // See if we seem to be on primordial process thread
1162 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) &&
1163 uintptr_t(&rlim) < stack_top;
1164
1165 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: "
1166 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT,
1167 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K,
1168 stack_top, intptr_t(_initial_thread_stack_bottom));
1169 }
1170 }
1171
1172 ////////////////////////////////////////////////////////////////////////////////
1173 // time support
1174
1175 // Time since start-up in seconds to a fine granularity.
1176 // Used by VMSelfDestructTimer and the MemProfiler.
1177 double os::elapsedTime() {
1178
1179 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
1180 }
1181
1182 jlong os::elapsed_counter() {
1183 return javaTimeNanos() - initial_time_count;
1184 }
1185
1186 jlong os::elapsed_frequency() {
1187 return NANOSECS_PER_SEC; // nanosecond resolution
1188 }
1189
1190 bool os::supports_vtime() { return true; }
1191 bool os::enable_vtime() { return false; }
1192 bool os::vtime_enabled() { return false; }
1193
1194 double os::elapsedVTime() {
1195 struct rusage usage;
1196 int retval = getrusage(RUSAGE_THREAD, &usage);
1197 if (retval == 0) {
1198 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);
1199 } else {
1200 // better than nothing, but not much
1201 return elapsedTime();
1202 }
1203 }
1204
1205 jlong os::javaTimeMillis() {
1206 timeval time;
1207 int status = gettimeofday(&time, NULL);
1208 assert(status != -1, "linux error");
1209 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
1210 }
1211
1212 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
1213 timeval time;
1214 int status = gettimeofday(&time, NULL);
1215 assert(status != -1, "linux error");
1216 seconds = jlong(time.tv_sec);
1217 nanos = jlong(time.tv_usec) * 1000;
1218 }
1219
1220
1221 #ifndef CLOCK_MONOTONIC
1222 #define CLOCK_MONOTONIC (1)
1223 #endif
1224
1225 void os::Linux::clock_init() {
1226 // we do dlopen's in this particular order due to bug in linux
1227 // dynamical loader (see 6348968) leading to crash on exit
1228 void* handle = dlopen("librt.so.1", RTLD_LAZY);
1229 if (handle == NULL) {
1230 handle = dlopen("librt.so", RTLD_LAZY);
1231 }
1232
1233 if (handle) {
1234 int (*clock_getres_func)(clockid_t, struct timespec*) =
1235 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1236 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1237 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1238 if (clock_getres_func && clock_gettime_func) {
1239 // See if monotonic clock is supported by the kernel. Note that some
1240 // early implementations simply return kernel jiffies (updated every
1241 // 1/100 or 1/1000 second). It would be bad to use such a low res clock
1242 // for nano time (though the monotonic property is still nice to have).
1243 // It's fixed in newer kernels, however clock_getres() still returns
1244 // 1/HZ. We check if clock_getres() works, but will ignore its reported
1245 // resolution for now. Hopefully as people move to new kernels, this
1246 // won't be a problem.
1247 struct timespec res;
1248 struct timespec tp;
1249 if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 &&
1250 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1251 // yes, monotonic clock is supported
1252 _clock_gettime = clock_gettime_func;
1253 return;
1254 } else {
1255 // close librt if there is no monotonic clock
1256 dlclose(handle);
1257 }
1258 }
1259 }
1260 warning("No monotonic clock was available - timed services may " \
1261 "be adversely affected if the time-of-day clock changes");
1262 }
1263
1264 #ifndef SYS_clock_getres
1265 #if defined(X86) || defined(PPC64) || defined(S390)
1266 #define SYS_clock_getres AMD64_ONLY(229) IA32_ONLY(266) PPC64_ONLY(247) S390_ONLY(261)
1267 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y)
1268 #else
1269 #warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time"
1270 #define sys_clock_getres(x,y) -1
1271 #endif
1272 #else
1273 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y)
1274 #endif
1275
1276 void os::Linux::fast_thread_clock_init() {
1277 if (!UseLinuxPosixThreadCPUClocks) {
1278 return;
1279 }
1280 clockid_t clockid;
1281 struct timespec tp;
1282 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) =
1283 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid");
1284
1285 // Switch to using fast clocks for thread cpu time if
1286 // the sys_clock_getres() returns 0 error code.
1287 // Note, that some kernels may support the current thread
1288 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks
1289 // returned by the pthread_getcpuclockid().
1290 // If the fast Posix clocks are supported then the sys_clock_getres()
1291 // must return at least tp.tv_sec == 0 which means a resolution
1292 // better than 1 sec. This is extra check for reliability.
1293
1294 if (pthread_getcpuclockid_func &&
1295 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 &&
1296 sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) {
1297 _supports_fast_thread_cpu_time = true;
1298 _pthread_getcpuclockid = pthread_getcpuclockid_func;
1299 }
1300 }
1301
1302 jlong os::javaTimeNanos() {
1303 if (os::supports_monotonic_clock()) {
1304 struct timespec tp;
1305 int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp);
1306 assert(status == 0, "gettime error");
1307 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1308 return result;
1309 } else {
1310 timeval time;
1311 int status = gettimeofday(&time, NULL);
1312 assert(status != -1, "linux error");
1313 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1314 return 1000 * usecs;
1315 }
1316 }
1317
1318 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1319 if (os::supports_monotonic_clock()) {
1320 info_ptr->max_value = ALL_64_BITS;
1321
1322 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1323 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1324 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1325 } else {
1326 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1327 info_ptr->max_value = ALL_64_BITS;
1328
1329 // gettimeofday is a real time clock so it skips
1330 info_ptr->may_skip_backward = true;
1331 info_ptr->may_skip_forward = true;
1332 }
1333
1334 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1335 }
1336
1337 // Return the real, user, and system times in seconds from an
1338 // arbitrary fixed point in the past.
1339 bool os::getTimesSecs(double* process_real_time,
1340 double* process_user_time,
1341 double* process_system_time) {
1342 struct tms ticks;
1343 clock_t real_ticks = times(&ticks);
1344
1345 if (real_ticks == (clock_t) (-1)) {
1346 return false;
1347 } else {
1348 double ticks_per_second = (double) clock_tics_per_sec;
1349 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1350 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1351 *process_real_time = ((double) real_ticks) / ticks_per_second;
1352
1353 return true;
1354 }
1355 }
1356
1357
1358 char * os::local_time_string(char *buf, size_t buflen) {
1359 struct tm t;
1360 time_t long_time;
1361 time(&long_time);
1362 localtime_r(&long_time, &t);
1363 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1364 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1365 t.tm_hour, t.tm_min, t.tm_sec);
1366 return buf;
1367 }
1368
1369 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1370 return localtime_r(clock, res);
1371 }
1372
1373 ////////////////////////////////////////////////////////////////////////////////
1374 // runtime exit support
1375
1376 // Note: os::shutdown() might be called very early during initialization, or
1377 // called from signal handler. Before adding something to os::shutdown(), make
1378 // sure it is async-safe and can handle partially initialized VM.
1379 void os::shutdown() {
1380
1381 // allow PerfMemory to attempt cleanup of any persistent resources
1382 perfMemory_exit();
1383
1384 // needs to remove object in file system
1385 AttachListener::abort();
1386
1387 // flush buffered output, finish log files
1388 ostream_abort();
1389
1390 // Check for abort hook
1391 abort_hook_t abort_hook = Arguments::abort_hook();
1392 if (abort_hook != NULL) {
1393 abort_hook();
1394 }
1395
1396 }
1397
1398 // Note: os::abort() might be called very early during initialization, or
1399 // called from signal handler. Before adding something to os::abort(), make
1400 // sure it is async-safe and can handle partially initialized VM.
1401 void os::abort(bool dump_core, void* siginfo, const void* context) {
1402 os::shutdown();
1403 if (dump_core) {
1404 #ifndef PRODUCT
1405 fdStream out(defaultStream::output_fd());
1406 out.print_raw("Current thread is ");
1407 char buf[16];
1408 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1409 out.print_raw_cr(buf);
1410 out.print_raw_cr("Dumping core ...");
1411 #endif
1412 ::abort(); // dump core
1413 }
1414
1415 ::exit(1);
1416 }
1417
1418 // Die immediately, no exit hook, no abort hook, no cleanup.
1419 void os::die() {
1420 ::abort();
1421 }
1422
1423
1424 // This method is a copy of JDK's sysGetLastErrorString
1425 // from src/solaris/hpi/src/system_md.c
1426
1427 size_t os::lasterror(char *buf, size_t len) {
1428 if (errno == 0) return 0;
1429
1430 const char *s = os::strerror(errno);
1431 size_t n = ::strlen(s);
1432 if (n >= len) {
1433 n = len - 1;
1434 }
1435 ::strncpy(buf, s, n);
1436 buf[n] = '\0';
1437 return n;
1438 }
1439
1440 // thread_id is kernel thread id (similar to Solaris LWP id)
1441 intx os::current_thread_id() { return os::Linux::gettid(); }
1442 int os::current_process_id() {
1443 return ::getpid();
1444 }
1445
1446 // DLL functions
1447
1448 const char* os::dll_file_extension() { return ".so"; }
1449
1450 // This must be hard coded because it's the system's temporary
1451 // directory not the java application's temp directory, ala java.io.tmpdir.
1452 const char* os::get_temp_directory() { return "/tmp"; }
1453
1454 static bool file_exists(const char* filename) {
1455 struct stat statbuf;
1456 if (filename == NULL || strlen(filename) == 0) {
1457 return false;
1458 }
1459 return os::stat(filename, &statbuf) == 0;
1460 }
1461
1462 // check if addr is inside libjvm.so
1463 bool os::address_is_in_vm(address addr) {
1464 static address libjvm_base_addr;
1465 Dl_info dlinfo;
1466
1467 if (libjvm_base_addr == NULL) {
1468 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1469 libjvm_base_addr = (address)dlinfo.dli_fbase;
1470 }
1471 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1472 }
1473
1474 if (dladdr((void *)addr, &dlinfo) != 0) {
1475 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1476 }
1477
1478 return false;
1479 }
1480
1481 bool os::dll_address_to_function_name(address addr, char *buf,
1482 int buflen, int *offset,
1483 bool demangle) {
1484 // buf is not optional, but offset is optional
1485 assert(buf != NULL, "sanity check");
1486
1487 Dl_info dlinfo;
1488
1489 if (dladdr((void*)addr, &dlinfo) != 0) {
1490 // see if we have a matching symbol
1491 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1492 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1493 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1494 }
1495 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1496 return true;
1497 }
1498 // no matching symbol so try for just file info
1499 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1500 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1501 buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1502 return true;
1503 }
1504 }
1505 }
1506
1507 buf[0] = '\0';
1508 if (offset != NULL) *offset = -1;
1509 return false;
1510 }
1511
1512 struct _address_to_library_name {
1513 address addr; // input : memory address
1514 size_t buflen; // size of fname
1515 char* fname; // output: library name
1516 address base; // library base addr
1517 };
1518
1519 static int address_to_library_name_callback(struct dl_phdr_info *info,
1520 size_t size, void *data) {
1521 int i;
1522 bool found = false;
1523 address libbase = NULL;
1524 struct _address_to_library_name * d = (struct _address_to_library_name *)data;
1525
1526 // iterate through all loadable segments
1527 for (i = 0; i < info->dlpi_phnum; i++) {
1528 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
1529 if (info->dlpi_phdr[i].p_type == PT_LOAD) {
1530 // base address of a library is the lowest address of its loaded
1531 // segments.
1532 if (libbase == NULL || libbase > segbase) {
1533 libbase = segbase;
1534 }
1535 // see if 'addr' is within current segment
1536 if (segbase <= d->addr &&
1537 d->addr < segbase + info->dlpi_phdr[i].p_memsz) {
1538 found = true;
1539 }
1540 }
1541 }
1542
1543 // dlpi_name is NULL or empty if the ELF file is executable, return 0
1544 // so dll_address_to_library_name() can fall through to use dladdr() which
1545 // can figure out executable name from argv[0].
1546 if (found && info->dlpi_name && info->dlpi_name[0]) {
1547 d->base = libbase;
1548 if (d->fname) {
1549 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name);
1550 }
1551 return 1;
1552 }
1553 return 0;
1554 }
1555
1556 bool os::dll_address_to_library_name(address addr, char* buf,
1557 int buflen, int* offset) {
1558 // buf is not optional, but offset is optional
1559 assert(buf != NULL, "sanity check");
1560
1561 Dl_info dlinfo;
1562 struct _address_to_library_name data;
1563
1564 // There is a bug in old glibc dladdr() implementation that it could resolve
1565 // to wrong library name if the .so file has a base address != NULL. Here
1566 // we iterate through the program headers of all loaded libraries to find
1567 // out which library 'addr' really belongs to. This workaround can be
1568 // removed once the minimum requirement for glibc is moved to 2.3.x.
1569 data.addr = addr;
1570 data.fname = buf;
1571 data.buflen = buflen;
1572 data.base = NULL;
1573 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data);
1574
1575 if (rslt) {
1576 // buf already contains library name
1577 if (offset) *offset = addr - data.base;
1578 return true;
1579 }
1580 if (dladdr((void*)addr, &dlinfo) != 0) {
1581 if (dlinfo.dli_fname != NULL) {
1582 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1583 }
1584 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1585 *offset = addr - (address)dlinfo.dli_fbase;
1586 }
1587 return true;
1588 }
1589
1590 buf[0] = '\0';
1591 if (offset) *offset = -1;
1592 return false;
1593 }
1594
1595 // Loads .dll/.so and
1596 // in case of error it checks if .dll/.so was built for the
1597 // same architecture as Hotspot is running on
1598
1599
1600 // Remember the stack's state. The Linux dynamic linker will change
1601 // the stack to 'executable' at most once, so we must safepoint only once.
1602 bool os::Linux::_stack_is_executable = false;
1603
1604 // VM operation that loads a library. This is necessary if stack protection
1605 // of the Java stacks can be lost during loading the library. If we
1606 // do not stop the Java threads, they can stack overflow before the stacks
1607 // are protected again.
1608 class VM_LinuxDllLoad: public VM_Operation {
1609 private:
1610 const char *_filename;
1611 char *_ebuf;
1612 int _ebuflen;
1613 void *_lib;
1614 public:
1615 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) :
1616 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {}
1617 VMOp_Type type() const { return VMOp_LinuxDllLoad; }
1618 void doit() {
1619 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen);
1620 os::Linux::_stack_is_executable = true;
1621 }
1622 void* loaded_library() { return _lib; }
1623 };
1624
1625 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1626 void * result = NULL;
1627 bool load_attempted = false;
1628
1629 // Check whether the library to load might change execution rights
1630 // of the stack. If they are changed, the protection of the stack
1631 // guard pages will be lost. We need a safepoint to fix this.
1632 //
1633 // See Linux man page execstack(8) for more info.
1634 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) {
1635 if (!ElfFile::specifies_noexecstack(filename)) {
1636 if (!is_init_completed()) {
1637 os::Linux::_stack_is_executable = true;
1638 // This is OK - No Java threads have been created yet, and hence no
1639 // stack guard pages to fix.
1640 //
1641 // This should happen only when you are building JDK7 using a very
1642 // old version of JDK6 (e.g., with JPRT) and running test_gamma.
1643 //
1644 // Dynamic loader will make all stacks executable after
1645 // this function returns, and will not do that again.
1646 assert(Threads::first() == NULL, "no Java threads should exist yet.");
1647 } else {
1648 warning("You have loaded library %s which might have disabled stack guard. "
1649 "The VM will try to fix the stack guard now.\n"
1650 "It's highly recommended that you fix the library with "
1651 "'execstack -c <libfile>', or link it with '-z noexecstack'.",
1652 filename);
1653
1654 assert(Thread::current()->is_Java_thread(), "must be Java thread");
1655 JavaThread *jt = JavaThread::current();
1656 if (jt->thread_state() != _thread_in_native) {
1657 // This happens when a compiler thread tries to load a hsdis-<arch>.so file
1658 // that requires ExecStack. Cannot enter safe point. Let's give up.
1659 warning("Unable to fix stack guard. Giving up.");
1660 } else {
1661 if (!LoadExecStackDllInVMThread) {
1662 // This is for the case where the DLL has an static
1663 // constructor function that executes JNI code. We cannot
1664 // load such DLLs in the VMThread.
1665 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1666 }
1667
1668 ThreadInVMfromNative tiv(jt);
1669 debug_only(VMNativeEntryWrapper vew;)
1670
1671 VM_LinuxDllLoad op(filename, ebuf, ebuflen);
1672 VMThread::execute(&op);
1673 if (LoadExecStackDllInVMThread) {
1674 result = op.loaded_library();
1675 }
1676 load_attempted = true;
1677 }
1678 }
1679 }
1680 }
1681
1682 if (!load_attempted) {
1683 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1684 }
1685
1686 if (result != NULL) {
1687 // Successful loading
1688 return result;
1689 }
1690
1691 Elf32_Ehdr elf_head;
1692 int diag_msg_max_length=ebuflen-strlen(ebuf);
1693 char* diag_msg_buf=ebuf+strlen(ebuf);
1694
1695 if (diag_msg_max_length==0) {
1696 // No more space in ebuf for additional diagnostics message
1697 return NULL;
1698 }
1699
1700
1701 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1702
1703 if (file_descriptor < 0) {
1704 // Can't open library, report dlerror() message
1705 return NULL;
1706 }
1707
1708 bool failed_to_read_elf_head=
1709 (sizeof(elf_head)!=
1710 (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1711
1712 ::close(file_descriptor);
1713 if (failed_to_read_elf_head) {
1714 // file i/o error - report dlerror() msg
1715 return NULL;
1716 }
1717
1718 typedef struct {
1719 Elf32_Half code; // Actual value as defined in elf.h
1720 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1721 unsigned char elf_class; // 32 or 64 bit
1722 unsigned char endianess; // MSB or LSB
1723 char* name; // String representation
1724 } arch_t;
1725
1726 #ifndef EM_486
1727 #define EM_486 6 /* Intel 80486 */
1728 #endif
1729 #ifndef EM_AARCH64
1730 #define EM_AARCH64 183 /* ARM AARCH64 */
1731 #endif
1732
1733 static const arch_t arch_array[]={
1734 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1735 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1736 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1737 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1738 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1739 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1740 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1741 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1742 #if defined(VM_LITTLE_ENDIAN)
1743 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"},
1744 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"},
1745 #else
1746 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1747 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"},
1748 #endif
1749 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1750 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1751 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1752 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1753 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1754 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1755 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"},
1756 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"},
1757 };
1758
1759 #if (defined IA32)
1760 static Elf32_Half running_arch_code=EM_386;
1761 #elif (defined AMD64)
1762 static Elf32_Half running_arch_code=EM_X86_64;
1763 #elif (defined IA64)
1764 static Elf32_Half running_arch_code=EM_IA_64;
1765 #elif (defined __sparc) && (defined _LP64)
1766 static Elf32_Half running_arch_code=EM_SPARCV9;
1767 #elif (defined __sparc) && (!defined _LP64)
1768 static Elf32_Half running_arch_code=EM_SPARC;
1769 #elif (defined __powerpc64__)
1770 static Elf32_Half running_arch_code=EM_PPC64;
1771 #elif (defined __powerpc__)
1772 static Elf32_Half running_arch_code=EM_PPC;
1773 #elif (defined AARCH64)
1774 static Elf32_Half running_arch_code=EM_AARCH64;
1775 #elif (defined ARM)
1776 static Elf32_Half running_arch_code=EM_ARM;
1777 #elif (defined S390)
1778 static Elf32_Half running_arch_code=EM_S390;
1779 #elif (defined ALPHA)
1780 static Elf32_Half running_arch_code=EM_ALPHA;
1781 #elif (defined MIPSEL)
1782 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1783 #elif (defined PARISC)
1784 static Elf32_Half running_arch_code=EM_PARISC;
1785 #elif (defined MIPS)
1786 static Elf32_Half running_arch_code=EM_MIPS;
1787 #elif (defined M68K)
1788 static Elf32_Half running_arch_code=EM_68K;
1789 #elif (defined SH)
1790 static Elf32_Half running_arch_code=EM_SH;
1791 #else
1792 #error Method os::dll_load requires that one of following is defined:\
1793 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc
1794 #endif
1795
1796 // Identify compatability class for VM's architecture and library's architecture
1797 // Obtain string descriptions for architectures
1798
1799 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1800 int running_arch_index=-1;
1801
1802 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1803 if (running_arch_code == arch_array[i].code) {
1804 running_arch_index = i;
1805 }
1806 if (lib_arch.code == arch_array[i].code) {
1807 lib_arch.compat_class = arch_array[i].compat_class;
1808 lib_arch.name = arch_array[i].name;
1809 }
1810 }
1811
1812 assert(running_arch_index != -1,
1813 "Didn't find running architecture code (running_arch_code) in arch_array");
1814 if (running_arch_index == -1) {
1815 // Even though running architecture detection failed
1816 // we may still continue with reporting dlerror() message
1817 return NULL;
1818 }
1819
1820 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1821 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1822 return NULL;
1823 }
1824
1825 #ifndef S390
1826 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1827 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1828 return NULL;
1829 }
1830 #endif // !S390
1831
1832 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1833 if (lib_arch.name!=NULL) {
1834 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1835 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1836 lib_arch.name, arch_array[running_arch_index].name);
1837 } else {
1838 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1839 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1840 lib_arch.code,
1841 arch_array[running_arch_index].name);
1842 }
1843 }
1844
1845 return NULL;
1846 }
1847
1848 void * os::Linux::dlopen_helper(const char *filename, char *ebuf,
1849 int ebuflen) {
1850 void * result = ::dlopen(filename, RTLD_LAZY);
1851 if (result == NULL) {
1852 ::strncpy(ebuf, ::dlerror(), ebuflen - 1);
1853 ebuf[ebuflen-1] = '\0';
1854 }
1855 return result;
1856 }
1857
1858 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf,
1859 int ebuflen) {
1860 void * result = NULL;
1861 if (LoadExecStackDllInVMThread) {
1862 result = dlopen_helper(filename, ebuf, ebuflen);
1863 }
1864
1865 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a
1866 // library that requires an executable stack, or which does not have this
1867 // stack attribute set, dlopen changes the stack attribute to executable. The
1868 // read protection of the guard pages gets lost.
1869 //
1870 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad
1871 // may have been queued at the same time.
1872
1873 if (!_stack_is_executable) {
1874 JavaThread *jt = Threads::first();
1875
1876 while (jt) {
1877 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized
1878 jt->stack_guards_enabled()) { // No pending stack overflow exceptions
1879 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) {
1880 warning("Attempt to reguard stack yellow zone failed.");
1881 }
1882 }
1883 jt = jt->next();
1884 }
1885 }
1886
1887 return result;
1888 }
1889
1890 void* os::dll_lookup(void* handle, const char* name) {
1891 void* res = dlsym(handle, name);
1892 return res;
1893 }
1894
1895 void* os::get_default_process_handle() {
1896 return (void*)::dlopen(NULL, RTLD_LAZY);
1897 }
1898
1899 static bool _print_ascii_file(const char* filename, outputStream* st) {
1900 int fd = ::open(filename, O_RDONLY);
1901 if (fd == -1) {
1902 return false;
1903 }
1904
1905 char buf[33];
1906 int bytes;
1907 buf[32] = '\0';
1908 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) {
1909 st->print_raw(buf, bytes);
1910 }
1911
1912 ::close(fd);
1913
1914 return true;
1915 }
1916
1917 void os::print_dll_info(outputStream *st) {
1918 st->print_cr("Dynamic libraries:");
1919
1920 char fname[32];
1921 pid_t pid = os::Linux::gettid();
1922
1923 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid);
1924
1925 if (!_print_ascii_file(fname, st)) {
1926 st->print("Can not get library information for pid = %d\n", pid);
1927 }
1928 }
1929
1930 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1931 FILE *procmapsFile = NULL;
1932
1933 // Open the procfs maps file for the current process
1934 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) {
1935 // Allocate PATH_MAX for file name plus a reasonable size for other fields.
1936 char line[PATH_MAX + 100];
1937
1938 // Read line by line from 'file'
1939 while (fgets(line, sizeof(line), procmapsFile) != NULL) {
1940 u8 base, top, offset, inode;
1941 char permissions[5];
1942 char device[6];
1943 char name[PATH_MAX + 1];
1944
1945 // Parse fields from line
1946 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s",
1947 &base, &top, permissions, &offset, device, &inode, name);
1948
1949 // Filter by device id '00:00' so that we only get file system mapped files.
1950 if (strcmp(device, "00:00") != 0) {
1951
1952 // Call callback with the fields of interest
1953 if(callback(name, (address)base, (address)top, param)) {
1954 // Oops abort, callback aborted
1955 fclose(procmapsFile);
1956 return 1;
1957 }
1958 }
1959 }
1960 fclose(procmapsFile);
1961 }
1962 return 0;
1963 }
1964
1965 void os::print_os_info_brief(outputStream* st) {
1966 os::Linux::print_distro_info(st);
1967
1968 os::Posix::print_uname_info(st);
1969
1970 os::Linux::print_libversion_info(st);
1971
1972 }
1973
1974 void os::print_os_info(outputStream* st) {
1975 st->print("OS:");
1976
1977 os::Linux::print_distro_info(st);
1978
1979 os::Posix::print_uname_info(st);
1980
1981 // Print warning if unsafe chroot environment detected
1982 if (unsafe_chroot_detected) {
1983 st->print("WARNING!! ");
1984 st->print_cr("%s", unstable_chroot_error);
1985 }
1986
1987 os::Linux::print_libversion_info(st);
1988
1989 os::Posix::print_rlimit_info(st);
1990
1991 os::Posix::print_load_average(st);
1992
1993 os::Linux::print_full_memory_info(st);
1994
1995 os::Linux::print_container_info(st);
1996 }
1997
1998 // Try to identify popular distros.
1999 // Most Linux distributions have a /etc/XXX-release file, which contains
2000 // the OS version string. Newer Linux distributions have a /etc/lsb-release
2001 // file that also contains the OS version string. Some have more than one
2002 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and
2003 // /etc/redhat-release.), so the order is important.
2004 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have
2005 // their own specific XXX-release file as well as a redhat-release file.
2006 // Because of this the XXX-release file needs to be searched for before the
2007 // redhat-release file.
2008 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the
2009 // search for redhat-release / SuSE-release needs to be before lsb-release.
2010 // Since the lsb-release file is the new standard it needs to be searched
2011 // before the older style release files.
2012 // Searching system-release (Red Hat) and os-release (other Linuxes) are a
2013 // next to last resort. The os-release file is a new standard that contains
2014 // distribution information and the system-release file seems to be an old
2015 // standard that has been replaced by the lsb-release and os-release files.
2016 // Searching for the debian_version file is the last resort. It contains
2017 // an informative string like "6.0.6" or "wheezy/sid". Because of this
2018 // "Debian " is printed before the contents of the debian_version file.
2019
2020 const char* distro_files[] = {
2021 "/etc/oracle-release",
2022 "/etc/mandriva-release",
2023 "/etc/mandrake-release",
2024 "/etc/sun-release",
2025 "/etc/redhat-release",
2026 "/etc/SuSE-release",
2027 "/etc/lsb-release",
2028 "/etc/turbolinux-release",
2029 "/etc/gentoo-release",
2030 "/etc/ltib-release",
2031 "/etc/angstrom-version",
2032 "/etc/system-release",
2033 "/etc/os-release",
2034 NULL };
2035
2036 void os::Linux::print_distro_info(outputStream* st) {
2037 for (int i = 0;; i++) {
2038 const char* file = distro_files[i];
2039 if (file == NULL) {
2040 break; // done
2041 }
2042 // If file prints, we found it.
2043 if (_print_ascii_file(file, st)) {
2044 return;
2045 }
2046 }
2047
2048 if (file_exists("/etc/debian_version")) {
2049 st->print("Debian ");
2050 _print_ascii_file("/etc/debian_version", st);
2051 } else {
2052 st->print("Linux");
2053 }
2054 st->cr();
2055 }
2056
2057 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) {
2058 char buf[256];
2059 while (fgets(buf, sizeof(buf), fp)) {
2060 // Edit out extra stuff in expected format
2061 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) {
2062 char* ptr = strstr(buf, "\""); // the name is in quotes
2063 if (ptr != NULL) {
2064 ptr++; // go beyond first quote
2065 char* nl = strchr(ptr, '\"');
2066 if (nl != NULL) *nl = '\0';
2067 strncpy(distro, ptr, length);
2068 } else {
2069 ptr = strstr(buf, "=");
2070 ptr++; // go beyond equals then
2071 char* nl = strchr(ptr, '\n');
2072 if (nl != NULL) *nl = '\0';
2073 strncpy(distro, ptr, length);
2074 }
2075 return;
2076 } else if (get_first_line) {
2077 char* nl = strchr(buf, '\n');
2078 if (nl != NULL) *nl = '\0';
2079 strncpy(distro, buf, length);
2080 return;
2081 }
2082 }
2083 // print last line and close
2084 char* nl = strchr(buf, '\n');
2085 if (nl != NULL) *nl = '\0';
2086 strncpy(distro, buf, length);
2087 }
2088
2089 static void parse_os_info(char* distro, size_t length, const char* file) {
2090 FILE* fp = fopen(file, "r");
2091 if (fp != NULL) {
2092 // if suse format, print out first line
2093 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0);
2094 parse_os_info_helper(fp, distro, length, get_first_line);
2095 fclose(fp);
2096 }
2097 }
2098
2099 void os::get_summary_os_info(char* buf, size_t buflen) {
2100 for (int i = 0;; i++) {
2101 const char* file = distro_files[i];
2102 if (file == NULL) {
2103 break; // ran out of distro_files
2104 }
2105 if (file_exists(file)) {
2106 parse_os_info(buf, buflen, file);
2107 return;
2108 }
2109 }
2110 // special case for debian
2111 if (file_exists("/etc/debian_version")) {
2112 strncpy(buf, "Debian ", buflen);
2113 parse_os_info(&buf[7], buflen-7, "/etc/debian_version");
2114 } else {
2115 strncpy(buf, "Linux", buflen);
2116 }
2117 }
2118
2119 void os::Linux::print_libversion_info(outputStream* st) {
2120 // libc, pthread
2121 st->print("libc:");
2122 st->print("%s ", os::Linux::glibc_version());
2123 st->print("%s ", os::Linux::libpthread_version());
2124 st->cr();
2125 }
2126
2127 void os::Linux::print_full_memory_info(outputStream* st) {
2128 st->print("\n/proc/meminfo:\n");
2129 _print_ascii_file("/proc/meminfo", st);
2130 st->cr();
2131 }
2132
2133 void os::Linux::print_container_info(outputStream* st) {
2134 if (OSContainer::is_containerized()) {
2135 st->print("container (cgroup) information:\n");
2136
2137 char *p = OSContainer::container_type();
2138 if (p == NULL)
2139 st->print("container_type() failed\n");
2140 else {
2141 st->print("container_type: %s\n", p);
2142 }
2143
2144 p = OSContainer::cpu_cpuset_cpus();
2145 if (p == NULL)
2146 st->print("cpu_cpuset_cpus() failed\n");
2147 else {
2148 st->print("cpu_cpuset_cpus: %s", p);
2149 free(p);
2150 }
2151
2152 p = OSContainer::cpu_cpuset_memory_nodes();
2153 if (p < 0)
2154 st->print("cpu_memory_nodes() failed\n");
2155 else {
2156 st->print("cpu_memory_nodes: %s", p);
2157 free(p);
2158 }
2159
2160 int i = OSContainer::active_processor_count();
2161 if (i < 0)
2162 st->print("active_processor_count() failed\n");
2163 else
2164 st->print("active_processor_count: %d\n", i);
2165
2166 i = OSContainer::cpu_quota();
2167 st->print("cpu_quota: %d\n", i);
2168
2169 i = OSContainer::cpu_period();
2170 st->print("cpu_period: %d\n", i);
2171
2172 i = OSContainer::cpu_shares();
2173 st->print("cpu_shares: %d\n", i);
2174
2175 jlong j = OSContainer::memory_limit_in_bytes();
2176 st->print("memory_limit_in_bytes: " JLONG_FORMAT "\n", j);
2177
2178 j = OSContainer::memory_and_swap_limit_in_bytes();
2179 st->print("memory_and_swap_limit_in_bytes: " JLONG_FORMAT "\n", j);
2180
2181 j = OSContainer::memory_soft_limit_in_bytes();
2182 st->print("memory_soft_limit_in_bytes: " JLONG_FORMAT "\n", j);
2183
2184 j = OSContainer::OSContainer::memory_usage_in_bytes();
2185 st->print("memory_usage_in_bytes: " JLONG_FORMAT "\n", j);
2186
2187 j = OSContainer::OSContainer::memory_max_usage_in_bytes();
2188 st->print("memory_max_usage_in_bytes: " JLONG_FORMAT "\n", j);
2189 st->cr();
2190 }
2191 }
2192
2193 void os::print_memory_info(outputStream* st) {
2194
2195 st->print("Memory:");
2196 st->print(" %dk page", os::vm_page_size()>>10);
2197
2198 // values in struct sysinfo are "unsigned long"
2199 struct sysinfo si;
2200 sysinfo(&si);
2201
2202 st->print(", physical " UINT64_FORMAT "k",
2203 os::physical_memory() >> 10);
2204 st->print("(" UINT64_FORMAT "k free)",
2205 os::available_memory() >> 10);
2206 st->print(", swap " UINT64_FORMAT "k",
2207 ((jlong)si.totalswap * si.mem_unit) >> 10);
2208 st->print("(" UINT64_FORMAT "k free)",
2209 ((jlong)si.freeswap * si.mem_unit) >> 10);
2210 st->cr();
2211 }
2212
2213 // Print the first "model name" line and the first "flags" line
2214 // that we find and nothing more. We assume "model name" comes
2215 // before "flags" so if we find a second "model name", then the
2216 // "flags" field is considered missing.
2217 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) {
2218 #if defined(IA32) || defined(AMD64)
2219 // Other platforms have less repetitive cpuinfo files
2220 FILE *fp = fopen("/proc/cpuinfo", "r");
2221 if (fp) {
2222 while (!feof(fp)) {
2223 if (fgets(buf, buflen, fp)) {
2224 // Assume model name comes before flags
2225 bool model_name_printed = false;
2226 if (strstr(buf, "model name") != NULL) {
2227 if (!model_name_printed) {
2228 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n");
2229 st->print_raw(buf);
2230 model_name_printed = true;
2231 } else {
2232 // model name printed but not flags? Odd, just return
2233 fclose(fp);
2234 return true;
2235 }
2236 }
2237 // print the flags line too
2238 if (strstr(buf, "flags") != NULL) {
2239 st->print_raw(buf);
2240 fclose(fp);
2241 return true;
2242 }
2243 }
2244 }
2245 fclose(fp);
2246 }
2247 #endif // x86 platforms
2248 return false;
2249 }
2250
2251 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
2252 // Only print the model name if the platform provides this as a summary
2253 if (!print_model_name_and_flags(st, buf, buflen)) {
2254 st->print("\n/proc/cpuinfo:\n");
2255 if (!_print_ascii_file("/proc/cpuinfo", st)) {
2256 st->print_cr(" <Not Available>");
2257 }
2258 }
2259 }
2260
2261 #if defined(AMD64) || defined(IA32) || defined(X32)
2262 const char* search_string = "model name";
2263 #elif defined(M68K)
2264 const char* search_string = "CPU";
2265 #elif defined(PPC64)
2266 const char* search_string = "cpu";
2267 #elif defined(S390)
2268 const char* search_string = "processor";
2269 #elif defined(SPARC)
2270 const char* search_string = "cpu";
2271 #else
2272 const char* search_string = "Processor";
2273 #endif
2274
2275 // Parses the cpuinfo file for string representing the model name.
2276 void os::get_summary_cpu_info(char* cpuinfo, size_t length) {
2277 FILE* fp = fopen("/proc/cpuinfo", "r");
2278 if (fp != NULL) {
2279 while (!feof(fp)) {
2280 char buf[256];
2281 if (fgets(buf, sizeof(buf), fp)) {
2282 char* start = strstr(buf, search_string);
2283 if (start != NULL) {
2284 char *ptr = start + strlen(search_string);
2285 char *end = buf + strlen(buf);
2286 while (ptr != end) {
2287 // skip whitespace and colon for the rest of the name.
2288 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') {
2289 break;
2290 }
2291 ptr++;
2292 }
2293 if (ptr != end) {
2294 // reasonable string, get rid of newline and keep the rest
2295 char* nl = strchr(buf, '\n');
2296 if (nl != NULL) *nl = '\0';
2297 strncpy(cpuinfo, ptr, length);
2298 fclose(fp);
2299 return;
2300 }
2301 }
2302 }
2303 }
2304 fclose(fp);
2305 }
2306 // cpuinfo not found or parsing failed, just print generic string. The entire
2307 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86)
2308 #if defined(AARCH64)
2309 strncpy(cpuinfo, "AArch64", length);
2310 #elif defined(AMD64)
2311 strncpy(cpuinfo, "x86_64", length);
2312 #elif defined(ARM) // Order wrt. AARCH64 is relevant!
2313 strncpy(cpuinfo, "ARM", length);
2314 #elif defined(IA32)
2315 strncpy(cpuinfo, "x86_32", length);
2316 #elif defined(IA64)
2317 strncpy(cpuinfo, "IA64", length);
2318 #elif defined(PPC)
2319 strncpy(cpuinfo, "PPC64", length);
2320 #elif defined(S390)
2321 strncpy(cpuinfo, "S390", length);
2322 #elif defined(SPARC)
2323 strncpy(cpuinfo, "sparcv9", length);
2324 #elif defined(ZERO_LIBARCH)
2325 strncpy(cpuinfo, ZERO_LIBARCH, length);
2326 #else
2327 strncpy(cpuinfo, "unknown", length);
2328 #endif
2329 }
2330
2331 static void print_signal_handler(outputStream* st, int sig,
2332 char* buf, size_t buflen);
2333
2334 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
2335 st->print_cr("Signal Handlers:");
2336 print_signal_handler(st, SIGSEGV, buf, buflen);
2337 print_signal_handler(st, SIGBUS , buf, buflen);
2338 print_signal_handler(st, SIGFPE , buf, buflen);
2339 print_signal_handler(st, SIGPIPE, buf, buflen);
2340 print_signal_handler(st, SIGXFSZ, buf, buflen);
2341 print_signal_handler(st, SIGILL , buf, buflen);
2342 print_signal_handler(st, SR_signum, buf, buflen);
2343 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
2344 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
2345 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
2346 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
2347 #if defined(PPC64)
2348 print_signal_handler(st, SIGTRAP, buf, buflen);
2349 #endif
2350 }
2351
2352 static char saved_jvm_path[MAXPATHLEN] = {0};
2353
2354 // Find the full path to the current module, libjvm.so
2355 void os::jvm_path(char *buf, jint buflen) {
2356 // Error checking.
2357 if (buflen < MAXPATHLEN) {
2358 assert(false, "must use a large-enough buffer");
2359 buf[0] = '\0';
2360 return;
2361 }
2362 // Lazy resolve the path to current module.
2363 if (saved_jvm_path[0] != 0) {
2364 strcpy(buf, saved_jvm_path);
2365 return;
2366 }
2367
2368 char dli_fname[MAXPATHLEN];
2369 bool ret = dll_address_to_library_name(
2370 CAST_FROM_FN_PTR(address, os::jvm_path),
2371 dli_fname, sizeof(dli_fname), NULL);
2372 assert(ret, "cannot locate libjvm");
2373 char *rp = NULL;
2374 if (ret && dli_fname[0] != '\0') {
2375 rp = os::Posix::realpath(dli_fname, buf, buflen);
2376 }
2377 if (rp == NULL) {
2378 return;
2379 }
2380
2381 if (Arguments::sun_java_launcher_is_altjvm()) {
2382 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
2383 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
2384 // If "/jre/lib/" appears at the right place in the string, then
2385 // assume we are installed in a JDK and we're done. Otherwise, check
2386 // for a JAVA_HOME environment variable and fix up the path so it
2387 // looks like libjvm.so is installed there (append a fake suffix
2388 // hotspot/libjvm.so).
2389 const char *p = buf + strlen(buf) - 1;
2390 for (int count = 0; p > buf && count < 5; ++count) {
2391 for (--p; p > buf && *p != '/'; --p)
2392 /* empty */ ;
2393 }
2394
2395 if (strncmp(p, "/jre/lib/", 9) != 0) {
2396 // Look for JAVA_HOME in the environment.
2397 char* java_home_var = ::getenv("JAVA_HOME");
2398 if (java_home_var != NULL && java_home_var[0] != 0) {
2399 char* jrelib_p;
2400 int len;
2401
2402 // Check the current module name "libjvm.so".
2403 p = strrchr(buf, '/');
2404 if (p == NULL) {
2405 return;
2406 }
2407 assert(strstr(p, "/libjvm") == p, "invalid library name");
2408
2409 rp = os::Posix::realpath(java_home_var, buf, buflen);
2410 if (rp == NULL) {
2411 return;
2412 }
2413
2414 // determine if this is a legacy image or modules image
2415 // modules image doesn't have "jre" subdirectory
2416 len = strlen(buf);
2417 assert(len < buflen, "Ran out of buffer room");
2418 jrelib_p = buf + len;
2419 snprintf(jrelib_p, buflen-len, "/jre/lib");
2420 if (0 != access(buf, F_OK)) {
2421 snprintf(jrelib_p, buflen-len, "/lib");
2422 }
2423
2424 if (0 == access(buf, F_OK)) {
2425 // Use current module name "libjvm.so"
2426 len = strlen(buf);
2427 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
2428 } else {
2429 // Go back to path of .so
2430 rp = os::Posix::realpath(dli_fname, buf, buflen);
2431 if (rp == NULL) {
2432 return;
2433 }
2434 }
2435 }
2436 }
2437 }
2438
2439 strncpy(saved_jvm_path, buf, MAXPATHLEN);
2440 saved_jvm_path[MAXPATHLEN - 1] = '\0';
2441 }
2442
2443 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
2444 // no prefix required, not even "_"
2445 }
2446
2447 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
2448 // no suffix required
2449 }
2450
2451 ////////////////////////////////////////////////////////////////////////////////
2452 // sun.misc.Signal support
2453
2454 static volatile jint sigint_count = 0;
2455
2456 static void UserHandler(int sig, void *siginfo, void *context) {
2457 // 4511530 - sem_post is serialized and handled by the manager thread. When
2458 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
2459 // don't want to flood the manager thread with sem_post requests.
2460 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
2461 return;
2462 }
2463
2464 // Ctrl-C is pressed during error reporting, likely because the error
2465 // handler fails to abort. Let VM die immediately.
2466 if (sig == SIGINT && VMError::is_error_reported()) {
2467 os::die();
2468 }
2469
2470 os::signal_notify(sig);
2471 }
2472
2473 void* os::user_handler() {
2474 return CAST_FROM_FN_PTR(void*, UserHandler);
2475 }
2476
2477 struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) {
2478 struct timespec ts;
2479 // Semaphore's are always associated with CLOCK_REALTIME
2480 os::Linux::clock_gettime(CLOCK_REALTIME, &ts);
2481 // see unpackTime for discussion on overflow checking
2482 if (sec >= MAX_SECS) {
2483 ts.tv_sec += MAX_SECS;
2484 ts.tv_nsec = 0;
2485 } else {
2486 ts.tv_sec += sec;
2487 ts.tv_nsec += nsec;
2488 if (ts.tv_nsec >= NANOSECS_PER_SEC) {
2489 ts.tv_nsec -= NANOSECS_PER_SEC;
2490 ++ts.tv_sec; // note: this must be <= max_secs
2491 }
2492 }
2493
2494 return ts;
2495 }
2496
2497 extern "C" {
2498 typedef void (*sa_handler_t)(int);
2499 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
2500 }
2501
2502 void* os::signal(int signal_number, void* handler) {
2503 struct sigaction sigAct, oldSigAct;
2504
2505 sigfillset(&(sigAct.sa_mask));
2506 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
2507 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
2508
2509 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
2510 // -1 means registration failed
2511 return (void *)-1;
2512 }
2513
2514 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
2515 }
2516
2517 void os::signal_raise(int signal_number) {
2518 ::raise(signal_number);
2519 }
2520
2521 // The following code is moved from os.cpp for making this
2522 // code platform specific, which it is by its very nature.
2523
2524 // Will be modified when max signal is changed to be dynamic
2525 int os::sigexitnum_pd() {
2526 return NSIG;
2527 }
2528
2529 // a counter for each possible signal value
2530 static volatile jint pending_signals[NSIG+1] = { 0 };
2531
2532 // Linux(POSIX) specific hand shaking semaphore.
2533 static sem_t sig_sem;
2534 static PosixSemaphore sr_semaphore;
2535
2536 void os::signal_init_pd() {
2537 // Initialize signal structures
2538 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2539
2540 // Initialize signal semaphore
2541 ::sem_init(&sig_sem, 0, 0);
2542 }
2543
2544 void os::signal_notify(int sig) {
2545 Atomic::inc(&pending_signals[sig]);
2546 ::sem_post(&sig_sem);
2547 }
2548
2549 static int check_pending_signals(bool wait) {
2550 Atomic::store(0, &sigint_count);
2551 for (;;) {
2552 for (int i = 0; i < NSIG + 1; i++) {
2553 jint n = pending_signals[i];
2554 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2555 return i;
2556 }
2557 }
2558 if (!wait) {
2559 return -1;
2560 }
2561 JavaThread *thread = JavaThread::current();
2562 ThreadBlockInVM tbivm(thread);
2563
2564 bool threadIsSuspended;
2565 do {
2566 thread->set_suspend_equivalent();
2567 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2568 ::sem_wait(&sig_sem);
2569
2570 // were we externally suspended while we were waiting?
2571 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2572 if (threadIsSuspended) {
2573 // The semaphore has been incremented, but while we were waiting
2574 // another thread suspended us. We don't want to continue running
2575 // while suspended because that would surprise the thread that
2576 // suspended us.
2577 ::sem_post(&sig_sem);
2578
2579 thread->java_suspend_self();
2580 }
2581 } while (threadIsSuspended);
2582 }
2583 }
2584
2585 int os::signal_lookup() {
2586 return check_pending_signals(false);
2587 }
2588
2589 int os::signal_wait() {
2590 return check_pending_signals(true);
2591 }
2592
2593 ////////////////////////////////////////////////////////////////////////////////
2594 // Virtual Memory
2595
2596 int os::vm_page_size() {
2597 // Seems redundant as all get out
2598 assert(os::Linux::page_size() != -1, "must call os::init");
2599 return os::Linux::page_size();
2600 }
2601
2602 // Solaris allocates memory by pages.
2603 int os::vm_allocation_granularity() {
2604 assert(os::Linux::page_size() != -1, "must call os::init");
2605 return os::Linux::page_size();
2606 }
2607
2608 // Rationale behind this function:
2609 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2610 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2611 // samples for JITted code. Here we create private executable mapping over the code cache
2612 // and then we can use standard (well, almost, as mapping can change) way to provide
2613 // info for the reporting script by storing timestamp and location of symbol
2614 void linux_wrap_code(char* base, size_t size) {
2615 static volatile jint cnt = 0;
2616
2617 if (!UseOprofile) {
2618 return;
2619 }
2620
2621 char buf[PATH_MAX+1];
2622 int num = Atomic::add(1, &cnt);
2623
2624 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d",
2625 os::get_temp_directory(), os::current_process_id(), num);
2626 unlink(buf);
2627
2628 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2629
2630 if (fd != -1) {
2631 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2632 if (rv != (off_t)-1) {
2633 if (::write(fd, "", 1) == 1) {
2634 mmap(base, size,
2635 PROT_READ|PROT_WRITE|PROT_EXEC,
2636 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2637 }
2638 }
2639 ::close(fd);
2640 unlink(buf);
2641 }
2642 }
2643
2644 static bool recoverable_mmap_error(int err) {
2645 // See if the error is one we can let the caller handle. This
2646 // list of errno values comes from JBS-6843484. I can't find a
2647 // Linux man page that documents this specific set of errno
2648 // values so while this list currently matches Solaris, it may
2649 // change as we gain experience with this failure mode.
2650 switch (err) {
2651 case EBADF:
2652 case EINVAL:
2653 case ENOTSUP:
2654 // let the caller deal with these errors
2655 return true;
2656
2657 default:
2658 // Any remaining errors on this OS can cause our reserved mapping
2659 // to be lost. That can cause confusion where different data
2660 // structures think they have the same memory mapped. The worst
2661 // scenario is if both the VM and a library think they have the
2662 // same memory mapped.
2663 return false;
2664 }
2665 }
2666
2667 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2668 int err) {
2669 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2670 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
2671 os::strerror(err), err);
2672 }
2673
2674 static void warn_fail_commit_memory(char* addr, size_t size,
2675 size_t alignment_hint, bool exec,
2676 int err) {
2677 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2678 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size,
2679 alignment_hint, exec, os::strerror(err), err);
2680 }
2681
2682 // NOTE: Linux kernel does not really reserve the pages for us.
2683 // All it does is to check if there are enough free pages
2684 // left at the time of mmap(). This could be a potential
2685 // problem.
2686 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) {
2687 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2688 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2689 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2690 if (res != (uintptr_t) MAP_FAILED) {
2691 if (UseNUMAInterleaving) {
2692 numa_make_global(addr, size);
2693 }
2694 return 0;
2695 }
2696
2697 int err = errno; // save errno from mmap() call above
2698
2699 if (!recoverable_mmap_error(err)) {
2700 warn_fail_commit_memory(addr, size, exec, err);
2701 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory.");
2702 }
2703
2704 return err;
2705 }
2706
2707 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2708 return os::Linux::commit_memory_impl(addr, size, exec) == 0;
2709 }
2710
2711 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2712 const char* mesg) {
2713 assert(mesg != NULL, "mesg must be specified");
2714 int err = os::Linux::commit_memory_impl(addr, size, exec);
2715 if (err != 0) {
2716 // the caller wants all commit errors to exit with the specified mesg:
2717 warn_fail_commit_memory(addr, size, exec, err);
2718 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2719 }
2720 }
2721
2722 // Define MAP_HUGETLB here so we can build HotSpot on old systems.
2723 #ifndef MAP_HUGETLB
2724 #define MAP_HUGETLB 0x40000
2725 #endif
2726
2727 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems.
2728 #ifndef MADV_HUGEPAGE
2729 #define MADV_HUGEPAGE 14
2730 #endif
2731
2732 int os::Linux::commit_memory_impl(char* addr, size_t size,
2733 size_t alignment_hint, bool exec) {
2734 int err = os::Linux::commit_memory_impl(addr, size, exec);
2735 if (err == 0) {
2736 realign_memory(addr, size, alignment_hint);
2737 }
2738 return err;
2739 }
2740
2741 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2742 bool exec) {
2743 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0;
2744 }
2745
2746 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2747 size_t alignment_hint, bool exec,
2748 const char* mesg) {
2749 assert(mesg != NULL, "mesg must be specified");
2750 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec);
2751 if (err != 0) {
2752 // the caller wants all commit errors to exit with the specified mesg:
2753 warn_fail_commit_memory(addr, size, alignment_hint, exec, err);
2754 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2755 }
2756 }
2757
2758 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2759 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) {
2760 // We don't check the return value: madvise(MADV_HUGEPAGE) may not
2761 // be supported or the memory may already be backed by huge pages.
2762 ::madvise(addr, bytes, MADV_HUGEPAGE);
2763 }
2764 }
2765
2766 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2767 // This method works by doing an mmap over an existing mmaping and effectively discarding
2768 // the existing pages. However it won't work for SHM-based large pages that cannot be
2769 // uncommitted at all. We don't do anything in this case to avoid creating a segment with
2770 // small pages on top of the SHM segment. This method always works for small pages, so we
2771 // allow that in any case.
2772 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) {
2773 commit_memory(addr, bytes, alignment_hint, !ExecMem);
2774 }
2775 }
2776
2777 void os::numa_make_global(char *addr, size_t bytes) {
2778 Linux::numa_interleave_memory(addr, bytes);
2779 }
2780
2781 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the
2782 // bind policy to MPOL_PREFERRED for the current thread.
2783 #define USE_MPOL_PREFERRED 0
2784
2785 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2786 // To make NUMA and large pages more robust when both enabled, we need to ease
2787 // the requirements on where the memory should be allocated. MPOL_BIND is the
2788 // default policy and it will force memory to be allocated on the specified
2789 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on
2790 // the specified node, but will not force it. Using this policy will prevent
2791 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no
2792 // free large pages.
2793 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED);
2794 Linux::numa_tonode_memory(addr, bytes, lgrp_hint);
2795 }
2796
2797 bool os::numa_topology_changed() { return false; }
2798
2799 size_t os::numa_get_groups_num() {
2800 // Return just the number of nodes in which it's possible to allocate memory
2801 // (in numa terminology, configured nodes).
2802 return Linux::numa_num_configured_nodes();
2803 }
2804
2805 int os::numa_get_group_id() {
2806 int cpu_id = Linux::sched_getcpu();
2807 if (cpu_id != -1) {
2808 int lgrp_id = Linux::get_node_by_cpu(cpu_id);
2809 if (lgrp_id != -1) {
2810 return lgrp_id;
2811 }
2812 }
2813 return 0;
2814 }
2815
2816 int os::Linux::get_existing_num_nodes() {
2817 size_t node;
2818 size_t highest_node_number = Linux::numa_max_node();
2819 int num_nodes = 0;
2820
2821 // Get the total number of nodes in the system including nodes without memory.
2822 for (node = 0; node <= highest_node_number; node++) {
2823 if (isnode_in_existing_nodes(node)) {
2824 num_nodes++;
2825 }
2826 }
2827 return num_nodes;
2828 }
2829
2830 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2831 size_t highest_node_number = Linux::numa_max_node();
2832 size_t i = 0;
2833
2834 // Map all node ids in which is possible to allocate memory. Also nodes are
2835 // not always consecutively available, i.e. available from 0 to the highest
2836 // node number.
2837 for (size_t node = 0; node <= highest_node_number; node++) {
2838 if (Linux::isnode_in_configured_nodes(node)) {
2839 ids[i++] = node;
2840 }
2841 }
2842 return i;
2843 }
2844
2845 bool os::get_page_info(char *start, page_info* info) {
2846 return false;
2847 }
2848
2849 char *os::scan_pages(char *start, char* end, page_info* page_expected,
2850 page_info* page_found) {
2851 return end;
2852 }
2853
2854
2855 int os::Linux::sched_getcpu_syscall(void) {
2856 unsigned int cpu = 0;
2857 int retval = -1;
2858
2859 #if defined(IA32)
2860 #ifndef SYS_getcpu
2861 #define SYS_getcpu 318
2862 #endif
2863 retval = syscall(SYS_getcpu, &cpu, NULL, NULL);
2864 #elif defined(AMD64)
2865 // Unfortunately we have to bring all these macros here from vsyscall.h
2866 // to be able to compile on old linuxes.
2867 #define __NR_vgetcpu 2
2868 #define VSYSCALL_START (-10UL << 20)
2869 #define VSYSCALL_SIZE 1024
2870 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
2871 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache);
2872 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu);
2873 retval = vgetcpu(&cpu, NULL, NULL);
2874 #endif
2875
2876 return (retval == -1) ? retval : cpu;
2877 }
2878
2879 void os::Linux::sched_getcpu_init() {
2880 // sched_getcpu() should be in libc.
2881 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
2882 dlsym(RTLD_DEFAULT, "sched_getcpu")));
2883
2884 // If it's not, try a direct syscall.
2885 if (sched_getcpu() == -1) {
2886 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
2887 (void*)&sched_getcpu_syscall));
2888 }
2889 }
2890
2891 // Something to do with the numa-aware allocator needs these symbols
2892 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { }
2893 extern "C" JNIEXPORT void numa_error(char *where) { }
2894
2895 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails
2896 // load symbol from base version instead.
2897 void* os::Linux::libnuma_dlsym(void* handle, const char *name) {
2898 void *f = dlvsym(handle, name, "libnuma_1.1");
2899 if (f == NULL) {
2900 f = dlsym(handle, name);
2901 }
2902 return f;
2903 }
2904
2905 // Handle request to load libnuma symbol version 1.2 (API v2) only.
2906 // Return NULL if the symbol is not defined in this particular version.
2907 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) {
2908 return dlvsym(handle, name, "libnuma_1.2");
2909 }
2910
2911 bool os::Linux::libnuma_init() {
2912 if (sched_getcpu() != -1) { // Requires sched_getcpu() support
2913 void *handle = dlopen("libnuma.so.1", RTLD_LAZY);
2914 if (handle != NULL) {
2915 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t,
2916 libnuma_dlsym(handle, "numa_node_to_cpus")));
2917 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t,
2918 libnuma_dlsym(handle, "numa_max_node")));
2919 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t,
2920 libnuma_dlsym(handle, "numa_num_configured_nodes")));
2921 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t,
2922 libnuma_dlsym(handle, "numa_available")));
2923 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t,
2924 libnuma_dlsym(handle, "numa_tonode_memory")));
2925 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t,
2926 libnuma_dlsym(handle, "numa_interleave_memory")));
2927 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t,
2928 libnuma_v2_dlsym(handle, "numa_interleave_memory")));
2929 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t,
2930 libnuma_dlsym(handle, "numa_set_bind_policy")));
2931 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t,
2932 libnuma_dlsym(handle, "numa_bitmask_isbitset")));
2933 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t,
2934 libnuma_dlsym(handle, "numa_distance")));
2935
2936 if (numa_available() != -1) {
2937 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes"));
2938 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr"));
2939 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr"));
2940 // Create an index -> node mapping, since nodes are not always consecutive
2941 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
2942 rebuild_nindex_to_node_map();
2943 // Create a cpu -> node mapping
2944 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
2945 rebuild_cpu_to_node_map();
2946 return true;
2947 }
2948 }
2949 }
2950 return false;
2951 }
2952
2953 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
2954 // Creating guard page is very expensive. Java thread has HotSpot
2955 // guard pages, only enable glibc guard page for non-Java threads.
2956 // (Remember: compiler thread is a Java thread, too!)
2957 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size());
2958 }
2959
2960 void os::Linux::rebuild_nindex_to_node_map() {
2961 int highest_node_number = Linux::numa_max_node();
2962
2963 nindex_to_node()->clear();
2964 for (int node = 0; node <= highest_node_number; node++) {
2965 if (Linux::isnode_in_existing_nodes(node)) {
2966 nindex_to_node()->append(node);
2967 }
2968 }
2969 }
2970
2971 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id.
2972 // The table is later used in get_node_by_cpu().
2973 void os::Linux::rebuild_cpu_to_node_map() {
2974 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure
2975 // in libnuma (possible values are starting from 16,
2976 // and continuing up with every other power of 2, but less
2977 // than the maximum number of CPUs supported by kernel), and
2978 // is a subject to change (in libnuma version 2 the requirements
2979 // are more reasonable) we'll just hardcode the number they use
2980 // in the library.
2981 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT;
2982
2983 size_t cpu_num = processor_count();
2984 size_t cpu_map_size = NCPUS / BitsPerCLong;
2985 size_t cpu_map_valid_size =
2986 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size);
2987
2988 cpu_to_node()->clear();
2989 cpu_to_node()->at_grow(cpu_num - 1);
2990
2991 size_t node_num = get_existing_num_nodes();
2992
2993 int distance = 0;
2994 int closest_distance = INT_MAX;
2995 int closest_node = 0;
2996 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal);
2997 for (size_t i = 0; i < node_num; i++) {
2998 // Check if node is configured (not a memory-less node). If it is not, find
2999 // the closest configured node.
3000 if (!isnode_in_configured_nodes(nindex_to_node()->at(i))) {
3001 closest_distance = INT_MAX;
3002 // Check distance from all remaining nodes in the system. Ignore distance
3003 // from itself and from another non-configured node.
3004 for (size_t m = 0; m < node_num; m++) {
3005 if (m != i && isnode_in_configured_nodes(nindex_to_node()->at(m))) {
3006 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m));
3007 // If a closest node is found, update. There is always at least one
3008 // configured node in the system so there is always at least one node
3009 // close.
3010 if (distance != 0 && distance < closest_distance) {
3011 closest_distance = distance;
3012 closest_node = nindex_to_node()->at(m);
3013 }
3014 }
3015 }
3016 } else {
3017 // Current node is already a configured node.
3018 closest_node = nindex_to_node()->at(i);
3019 }
3020
3021 // Get cpus from the original node and map them to the closest node. If node
3022 // is a configured node (not a memory-less node), then original node and
3023 // closest node are the same.
3024 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) {
3025 for (size_t j = 0; j < cpu_map_valid_size; j++) {
3026 if (cpu_map[j] != 0) {
3027 for (size_t k = 0; k < BitsPerCLong; k++) {
3028 if (cpu_map[j] & (1UL << k)) {
3029 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node);
3030 }
3031 }
3032 }
3033 }
3034 }
3035 }
3036 FREE_C_HEAP_ARRAY(unsigned long, cpu_map);
3037 }
3038
3039 int os::Linux::get_node_by_cpu(int cpu_id) {
3040 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) {
3041 return cpu_to_node()->at(cpu_id);
3042 }
3043 return -1;
3044 }
3045
3046 GrowableArray<int>* os::Linux::_cpu_to_node;
3047 GrowableArray<int>* os::Linux::_nindex_to_node;
3048 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu;
3049 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus;
3050 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node;
3051 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes;
3052 os::Linux::numa_available_func_t os::Linux::_numa_available;
3053 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory;
3054 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory;
3055 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2;
3056 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy;
3057 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset;
3058 os::Linux::numa_distance_func_t os::Linux::_numa_distance;
3059 unsigned long* os::Linux::_numa_all_nodes;
3060 struct bitmask* os::Linux::_numa_all_nodes_ptr;
3061 struct bitmask* os::Linux::_numa_nodes_ptr;
3062
3063 bool os::pd_uncommit_memory(char* addr, size_t size) {
3064 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
3065 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
3066 return res != (uintptr_t) MAP_FAILED;
3067 }
3068
3069 static address get_stack_commited_bottom(address bottom, size_t size) {
3070 address nbot = bottom;
3071 address ntop = bottom + size;
3072
3073 size_t page_sz = os::vm_page_size();
3074 unsigned pages = size / page_sz;
3075
3076 unsigned char vec[1];
3077 unsigned imin = 1, imax = pages + 1, imid;
3078 int mincore_return_value = 0;
3079
3080 assert(imin <= imax, "Unexpected page size");
3081
3082 while (imin < imax) {
3083 imid = (imax + imin) / 2;
3084 nbot = ntop - (imid * page_sz);
3085
3086 // Use a trick with mincore to check whether the page is mapped or not.
3087 // mincore sets vec to 1 if page resides in memory and to 0 if page
3088 // is swapped output but if page we are asking for is unmapped
3089 // it returns -1,ENOMEM
3090 mincore_return_value = mincore(nbot, page_sz, vec);
3091
3092 if (mincore_return_value == -1) {
3093 // Page is not mapped go up
3094 // to find first mapped page
3095 if (errno != EAGAIN) {
3096 assert(errno == ENOMEM, "Unexpected mincore errno");
3097 imax = imid;
3098 }
3099 } else {
3100 // Page is mapped go down
3101 // to find first not mapped page
3102 imin = imid + 1;
3103 }
3104 }
3105
3106 nbot = nbot + page_sz;
3107
3108 // Adjust stack bottom one page up if last checked page is not mapped
3109 if (mincore_return_value == -1) {
3110 nbot = nbot + page_sz;
3111 }
3112
3113 return nbot;
3114 }
3115
3116
3117 // Linux uses a growable mapping for the stack, and if the mapping for
3118 // the stack guard pages is not removed when we detach a thread the
3119 // stack cannot grow beyond the pages where the stack guard was
3120 // mapped. If at some point later in the process the stack expands to
3121 // that point, the Linux kernel cannot expand the stack any further
3122 // because the guard pages are in the way, and a segfault occurs.
3123 //
3124 // However, it's essential not to split the stack region by unmapping
3125 // a region (leaving a hole) that's already part of the stack mapping,
3126 // so if the stack mapping has already grown beyond the guard pages at
3127 // the time we create them, we have to truncate the stack mapping.
3128 // So, we need to know the extent of the stack mapping when
3129 // create_stack_guard_pages() is called.
3130
3131 // We only need this for stacks that are growable: at the time of
3132 // writing thread stacks don't use growable mappings (i.e. those
3133 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this
3134 // only applies to the main thread.
3135
3136 // If the (growable) stack mapping already extends beyond the point
3137 // where we're going to put our guard pages, truncate the mapping at
3138 // that point by munmap()ping it. This ensures that when we later
3139 // munmap() the guard pages we don't leave a hole in the stack
3140 // mapping. This only affects the main/initial thread
3141
3142 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
3143 if (os::Linux::is_initial_thread()) {
3144 // As we manually grow stack up to bottom inside create_attached_thread(),
3145 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and
3146 // we don't need to do anything special.
3147 // Check it first, before calling heavy function.
3148 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom();
3149 unsigned char vec[1];
3150
3151 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) {
3152 // Fallback to slow path on all errors, including EAGAIN
3153 stack_extent = (uintptr_t) get_stack_commited_bottom(
3154 os::Linux::initial_thread_stack_bottom(),
3155 (size_t)addr - stack_extent);
3156 }
3157
3158 if (stack_extent < (uintptr_t)addr) {
3159 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent));
3160 }
3161 }
3162
3163 return os::commit_memory(addr, size, !ExecMem);
3164 }
3165
3166 // If this is a growable mapping, remove the guard pages entirely by
3167 // munmap()ping them. If not, just call uncommit_memory(). This only
3168 // affects the main/initial thread, but guard against future OS changes
3169 // It's safe to always unmap guard pages for initial thread because we
3170 // always place it right after end of the mapped region
3171
3172 bool os::remove_stack_guard_pages(char* addr, size_t size) {
3173 uintptr_t stack_extent, stack_base;
3174
3175 if (os::Linux::is_initial_thread()) {
3176 return ::munmap(addr, size) == 0;
3177 }
3178
3179 return os::uncommit_memory(addr, size);
3180 }
3181
3182 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
3183 // at 'requested_addr'. If there are existing memory mappings at the same
3184 // location, however, they will be overwritten. If 'fixed' is false,
3185 // 'requested_addr' is only treated as a hint, the return value may or
3186 // may not start from the requested address. Unlike Linux mmap(), this
3187 // function returns NULL to indicate failure.
3188 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
3189 char * addr;
3190 int flags;
3191
3192 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
3193 if (fixed) {
3194 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address");
3195 flags |= MAP_FIXED;
3196 }
3197
3198 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
3199 // touch an uncommitted page. Otherwise, the read/write might
3200 // succeed if we have enough swap space to back the physical page.
3201 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
3202 flags, -1, 0);
3203
3204 return addr == MAP_FAILED ? NULL : addr;
3205 }
3206
3207 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address
3208 // (req_addr != NULL) or with a given alignment.
3209 // - bytes shall be a multiple of alignment.
3210 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3211 // - alignment sets the alignment at which memory shall be allocated.
3212 // It must be a multiple of allocation granularity.
3213 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3214 // req_addr or NULL.
3215 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) {
3216
3217 size_t extra_size = bytes;
3218 if (req_addr == NULL && alignment > 0) {
3219 extra_size += alignment;
3220 }
3221
3222 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE,
3223 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
3224 -1, 0);
3225 if (start == MAP_FAILED) {
3226 start = NULL;
3227 } else {
3228 if (req_addr != NULL) {
3229 if (start != req_addr) {
3230 ::munmap(start, extra_size);
3231 start = NULL;
3232 }
3233 } else {
3234 char* const start_aligned = align_up(start, alignment);
3235 char* const end_aligned = start_aligned + bytes;
3236 char* const end = start + extra_size;
3237 if (start_aligned > start) {
3238 ::munmap(start, start_aligned - start);
3239 }
3240 if (end_aligned < end) {
3241 ::munmap(end_aligned, end - end_aligned);
3242 }
3243 start = start_aligned;
3244 }
3245 }
3246 return start;
3247 }
3248
3249 static int anon_munmap(char * addr, size_t size) {
3250 return ::munmap(addr, size) == 0;
3251 }
3252
3253 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
3254 size_t alignment_hint) {
3255 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
3256 }
3257
3258 bool os::pd_release_memory(char* addr, size_t size) {
3259 return anon_munmap(addr, size);
3260 }
3261
3262 static bool linux_mprotect(char* addr, size_t size, int prot) {
3263 // Linux wants the mprotect address argument to be page aligned.
3264 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size());
3265
3266 // According to SUSv3, mprotect() should only be used with mappings
3267 // established by mmap(), and mmap() always maps whole pages. Unaligned
3268 // 'addr' likely indicates problem in the VM (e.g. trying to change
3269 // protection of malloc'ed or statically allocated memory). Check the
3270 // caller if you hit this assert.
3271 assert(addr == bottom, "sanity check");
3272
3273 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size());
3274 return ::mprotect(bottom, size, prot) == 0;
3275 }
3276
3277 // Set protections specified
3278 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
3279 bool is_committed) {
3280 unsigned int p = 0;
3281 switch (prot) {
3282 case MEM_PROT_NONE: p = PROT_NONE; break;
3283 case MEM_PROT_READ: p = PROT_READ; break;
3284 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
3285 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
3286 default:
3287 ShouldNotReachHere();
3288 }
3289 // is_committed is unused.
3290 return linux_mprotect(addr, bytes, p);
3291 }
3292
3293 bool os::guard_memory(char* addr, size_t size) {
3294 return linux_mprotect(addr, size, PROT_NONE);
3295 }
3296
3297 bool os::unguard_memory(char* addr, size_t size) {
3298 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE);
3299 }
3300
3301 bool os::Linux::transparent_huge_pages_sanity_check(bool warn,
3302 size_t page_size) {
3303 bool result = false;
3304 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,
3305 MAP_ANONYMOUS|MAP_PRIVATE,
3306 -1, 0);
3307 if (p != MAP_FAILED) {
3308 void *aligned_p = align_up(p, page_size);
3309
3310 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0;
3311
3312 munmap(p, page_size * 2);
3313 }
3314
3315 if (warn && !result) {
3316 warning("TransparentHugePages is not supported by the operating system.");
3317 }
3318
3319 return result;
3320 }
3321
3322 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) {
3323 bool result = false;
3324 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
3325 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB,
3326 -1, 0);
3327
3328 if (p != MAP_FAILED) {
3329 // We don't know if this really is a huge page or not.
3330 FILE *fp = fopen("/proc/self/maps", "r");
3331 if (fp) {
3332 while (!feof(fp)) {
3333 char chars[257];
3334 long x = 0;
3335 if (fgets(chars, sizeof(chars), fp)) {
3336 if (sscanf(chars, "%lx-%*x", &x) == 1
3337 && x == (long)p) {
3338 if (strstr (chars, "hugepage")) {
3339 result = true;
3340 break;
3341 }
3342 }
3343 }
3344 }
3345 fclose(fp);
3346 }
3347 munmap(p, page_size);
3348 }
3349
3350 if (warn && !result) {
3351 warning("HugeTLBFS is not supported by the operating system.");
3352 }
3353
3354 return result;
3355 }
3356
3357 // Set the coredump_filter bits to include largepages in core dump (bit 6)
3358 //
3359 // From the coredump_filter documentation:
3360 //
3361 // - (bit 0) anonymous private memory
3362 // - (bit 1) anonymous shared memory
3363 // - (bit 2) file-backed private memory
3364 // - (bit 3) file-backed shared memory
3365 // - (bit 4) ELF header pages in file-backed private memory areas (it is
3366 // effective only if the bit 2 is cleared)
3367 // - (bit 5) hugetlb private memory
3368 // - (bit 6) hugetlb shared memory
3369 //
3370 static void set_coredump_filter(void) {
3371 FILE *f;
3372 long cdm;
3373
3374 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
3375 return;
3376 }
3377
3378 if (fscanf(f, "%lx", &cdm) != 1) {
3379 fclose(f);
3380 return;
3381 }
3382
3383 rewind(f);
3384
3385 if ((cdm & LARGEPAGES_BIT) == 0) {
3386 cdm |= LARGEPAGES_BIT;
3387 fprintf(f, "%#lx", cdm);
3388 }
3389
3390 fclose(f);
3391 }
3392
3393 // Large page support
3394
3395 static size_t _large_page_size = 0;
3396
3397 size_t os::Linux::find_large_page_size() {
3398 size_t large_page_size = 0;
3399
3400 // large_page_size on Linux is used to round up heap size. x86 uses either
3401 // 2M or 4M page, depending on whether PAE (Physical Address Extensions)
3402 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use
3403 // page as large as 256M.
3404 //
3405 // Here we try to figure out page size by parsing /proc/meminfo and looking
3406 // for a line with the following format:
3407 // Hugepagesize: 2048 kB
3408 //
3409 // If we can't determine the value (e.g. /proc is not mounted, or the text
3410 // format has been changed), we'll use the largest page size supported by
3411 // the processor.
3412
3413 #ifndef ZERO
3414 large_page_size =
3415 AARCH64_ONLY(2 * M)
3416 AMD64_ONLY(2 * M)
3417 ARM32_ONLY(2 * M)
3418 IA32_ONLY(4 * M)
3419 IA64_ONLY(256 * M)
3420 PPC_ONLY(4 * M)
3421 S390_ONLY(1 * M)
3422 SPARC_ONLY(4 * M);
3423 #endif // ZERO
3424
3425 FILE *fp = fopen("/proc/meminfo", "r");
3426 if (fp) {
3427 while (!feof(fp)) {
3428 int x = 0;
3429 char buf[16];
3430 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) {
3431 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) {
3432 large_page_size = x * K;
3433 break;
3434 }
3435 } else {
3436 // skip to next line
3437 for (;;) {
3438 int ch = fgetc(fp);
3439 if (ch == EOF || ch == (int)'\n') break;
3440 }
3441 }
3442 }
3443 fclose(fp);
3444 }
3445
3446 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) {
3447 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is "
3448 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size),
3449 proper_unit_for_byte_size(large_page_size));
3450 }
3451
3452 return large_page_size;
3453 }
3454
3455 size_t os::Linux::setup_large_page_size() {
3456 _large_page_size = Linux::find_large_page_size();
3457 const size_t default_page_size = (size_t)Linux::page_size();
3458 if (_large_page_size > default_page_size) {
3459 _page_sizes[0] = _large_page_size;
3460 _page_sizes[1] = default_page_size;
3461 _page_sizes[2] = 0;
3462 }
3463
3464 return _large_page_size;
3465 }
3466
3467 bool os::Linux::setup_large_page_type(size_t page_size) {
3468 if (FLAG_IS_DEFAULT(UseHugeTLBFS) &&
3469 FLAG_IS_DEFAULT(UseSHM) &&
3470 FLAG_IS_DEFAULT(UseTransparentHugePages)) {
3471
3472 // The type of large pages has not been specified by the user.
3473
3474 // Try UseHugeTLBFS and then UseSHM.
3475 UseHugeTLBFS = UseSHM = true;
3476
3477 // Don't try UseTransparentHugePages since there are known
3478 // performance issues with it turned on. This might change in the future.
3479 UseTransparentHugePages = false;
3480 }
3481
3482 if (UseTransparentHugePages) {
3483 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages);
3484 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) {
3485 UseHugeTLBFS = false;
3486 UseSHM = false;
3487 return true;
3488 }
3489 UseTransparentHugePages = false;
3490 }
3491
3492 if (UseHugeTLBFS) {
3493 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS);
3494 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) {
3495 UseSHM = false;
3496 return true;
3497 }
3498 UseHugeTLBFS = false;
3499 }
3500
3501 return UseSHM;
3502 }
3503
3504 void os::large_page_init() {
3505 if (!UseLargePages &&
3506 !UseTransparentHugePages &&
3507 !UseHugeTLBFS &&
3508 !UseSHM) {
3509 // Not using large pages.
3510 return;
3511 }
3512
3513 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) {
3514 // The user explicitly turned off large pages.
3515 // Ignore the rest of the large pages flags.
3516 UseTransparentHugePages = false;
3517 UseHugeTLBFS = false;
3518 UseSHM = false;
3519 return;
3520 }
3521
3522 size_t large_page_size = Linux::setup_large_page_size();
3523 UseLargePages = Linux::setup_large_page_type(large_page_size);
3524
3525 set_coredump_filter();
3526 }
3527
3528 #ifndef SHM_HUGETLB
3529 #define SHM_HUGETLB 04000
3530 #endif
3531
3532 #define shm_warning_format(format, ...) \
3533 do { \
3534 if (UseLargePages && \
3535 (!FLAG_IS_DEFAULT(UseLargePages) || \
3536 !FLAG_IS_DEFAULT(UseSHM) || \
3537 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \
3538 warning(format, __VA_ARGS__); \
3539 } \
3540 } while (0)
3541
3542 #define shm_warning(str) shm_warning_format("%s", str)
3543
3544 #define shm_warning_with_errno(str) \
3545 do { \
3546 int err = errno; \
3547 shm_warning_format(str " (error = %d)", err); \
3548 } while (0)
3549
3550 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) {
3551 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment");
3552
3553 if (!is_aligned(alignment, SHMLBA)) {
3554 assert(false, "Code below assumes that alignment is at least SHMLBA aligned");
3555 return NULL;
3556 }
3557
3558 // To ensure that we get 'alignment' aligned memory from shmat,
3559 // we pre-reserve aligned virtual memory and then attach to that.
3560
3561 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL);
3562 if (pre_reserved_addr == NULL) {
3563 // Couldn't pre-reserve aligned memory.
3564 shm_warning("Failed to pre-reserve aligned memory for shmat.");
3565 return NULL;
3566 }
3567
3568 // SHM_REMAP is needed to allow shmat to map over an existing mapping.
3569 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP);
3570
3571 if ((intptr_t)addr == -1) {
3572 int err = errno;
3573 shm_warning_with_errno("Failed to attach shared memory.");
3574
3575 assert(err != EACCES, "Unexpected error");
3576 assert(err != EIDRM, "Unexpected error");
3577 assert(err != EINVAL, "Unexpected error");
3578
3579 // Since we don't know if the kernel unmapped the pre-reserved memory area
3580 // we can't unmap it, since that would potentially unmap memory that was
3581 // mapped from other threads.
3582 return NULL;
3583 }
3584
3585 return addr;
3586 }
3587
3588 static char* shmat_at_address(int shmid, char* req_addr) {
3589 if (!is_aligned(req_addr, SHMLBA)) {
3590 assert(false, "Requested address needs to be SHMLBA aligned");
3591 return NULL;
3592 }
3593
3594 char* addr = (char*)shmat(shmid, req_addr, 0);
3595
3596 if ((intptr_t)addr == -1) {
3597 shm_warning_with_errno("Failed to attach shared memory.");
3598 return NULL;
3599 }
3600
3601 return addr;
3602 }
3603
3604 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) {
3605 // If a req_addr has been provided, we assume that the caller has already aligned the address.
3606 if (req_addr != NULL) {
3607 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size");
3608 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment");
3609 return shmat_at_address(shmid, req_addr);
3610 }
3611
3612 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically
3613 // return large page size aligned memory addresses when req_addr == NULL.
3614 // However, if the alignment is larger than the large page size, we have
3615 // to manually ensure that the memory returned is 'alignment' aligned.
3616 if (alignment > os::large_page_size()) {
3617 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size");
3618 return shmat_with_alignment(shmid, bytes, alignment);
3619 } else {
3620 return shmat_at_address(shmid, NULL);
3621 }
3622 }
3623
3624 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment,
3625 char* req_addr, bool exec) {
3626 // "exec" is passed in but not used. Creating the shared image for
3627 // the code cache doesn't have an SHM_X executable permission to check.
3628 assert(UseLargePages && UseSHM, "only for SHM large pages");
3629 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
3630 assert(is_aligned(req_addr, alignment), "Unaligned address");
3631
3632 if (!is_aligned(bytes, os::large_page_size())) {
3633 return NULL; // Fallback to small pages.
3634 }
3635
3636 // Create a large shared memory region to attach to based on size.
3637 // Currently, size is the total size of the heap.
3638 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);
3639 if (shmid == -1) {
3640 // Possible reasons for shmget failure:
3641 // 1. shmmax is too small for Java heap.
3642 // > check shmmax value: cat /proc/sys/kernel/shmmax
3643 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
3644 // 2. not enough large page memory.
3645 // > check available large pages: cat /proc/meminfo
3646 // > increase amount of large pages:
3647 // echo new_value > /proc/sys/vm/nr_hugepages
3648 // Note 1: different Linux may use different name for this property,
3649 // e.g. on Redhat AS-3 it is "hugetlb_pool".
3650 // Note 2: it's possible there's enough physical memory available but
3651 // they are so fragmented after a long run that they can't
3652 // coalesce into large pages. Try to reserve large pages when
3653 // the system is still "fresh".
3654 shm_warning_with_errno("Failed to reserve shared memory.");
3655 return NULL;
3656 }
3657
3658 // Attach to the region.
3659 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr);
3660
3661 // Remove shmid. If shmat() is successful, the actual shared memory segment
3662 // will be deleted when it's detached by shmdt() or when the process
3663 // terminates. If shmat() is not successful this will remove the shared
3664 // segment immediately.
3665 shmctl(shmid, IPC_RMID, NULL);
3666
3667 return addr;
3668 }
3669
3670 static void warn_on_large_pages_failure(char* req_addr, size_t bytes,
3671 int error) {
3672 assert(error == ENOMEM, "Only expect to fail if no memory is available");
3673
3674 bool warn_on_failure = UseLargePages &&
3675 (!FLAG_IS_DEFAULT(UseLargePages) ||
3676 !FLAG_IS_DEFAULT(UseHugeTLBFS) ||
3677 !FLAG_IS_DEFAULT(LargePageSizeInBytes));
3678
3679 if (warn_on_failure) {
3680 char msg[128];
3681 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: "
3682 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error);
3683 warning("%s", msg);
3684 }
3685 }
3686
3687 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes,
3688 char* req_addr,
3689 bool exec) {
3690 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
3691 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size");
3692 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
3693
3694 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
3695 char* addr = (char*)::mmap(req_addr, bytes, prot,
3696 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB,
3697 -1, 0);
3698
3699 if (addr == MAP_FAILED) {
3700 warn_on_large_pages_failure(req_addr, bytes, errno);
3701 return NULL;
3702 }
3703
3704 assert(is_aligned(addr, os::large_page_size()), "Must be");
3705
3706 return addr;
3707 }
3708
3709 // Reserve memory using mmap(MAP_HUGETLB).
3710 // - bytes shall be a multiple of alignment.
3711 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3712 // - alignment sets the alignment at which memory shall be allocated.
3713 // It must be a multiple of allocation granularity.
3714 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3715 // req_addr or NULL.
3716 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes,
3717 size_t alignment,
3718 char* req_addr,
3719 bool exec) {
3720 size_t large_page_size = os::large_page_size();
3721 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes");
3722
3723 assert(is_aligned(req_addr, alignment), "Must be");
3724 assert(is_aligned(bytes, alignment), "Must be");
3725
3726 // First reserve - but not commit - the address range in small pages.
3727 char* const start = anon_mmap_aligned(bytes, alignment, req_addr);
3728
3729 if (start == NULL) {
3730 return NULL;
3731 }
3732
3733 assert(is_aligned(start, alignment), "Must be");
3734
3735 char* end = start + bytes;
3736
3737 // Find the regions of the allocated chunk that can be promoted to large pages.
3738 char* lp_start = align_up(start, large_page_size);
3739 char* lp_end = align_down(end, large_page_size);
3740
3741 size_t lp_bytes = lp_end - lp_start;
3742
3743 assert(is_aligned(lp_bytes, large_page_size), "Must be");
3744
3745 if (lp_bytes == 0) {
3746 // The mapped region doesn't even span the start and the end of a large page.
3747 // Fall back to allocate a non-special area.
3748 ::munmap(start, end - start);
3749 return NULL;
3750 }
3751
3752 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
3753
3754 void* result;
3755
3756 // Commit small-paged leading area.
3757 if (start != lp_start) {
3758 result = ::mmap(start, lp_start - start, prot,
3759 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
3760 -1, 0);
3761 if (result == MAP_FAILED) {
3762 ::munmap(lp_start, end - lp_start);
3763 return NULL;
3764 }
3765 }
3766
3767 // Commit large-paged area.
3768 result = ::mmap(lp_start, lp_bytes, prot,
3769 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB,
3770 -1, 0);
3771 if (result == MAP_FAILED) {
3772 warn_on_large_pages_failure(lp_start, lp_bytes, errno);
3773 // If the mmap above fails, the large pages region will be unmapped and we
3774 // have regions before and after with small pages. Release these regions.
3775 //
3776 // | mapped | unmapped | mapped |
3777 // ^ ^ ^ ^
3778 // start lp_start lp_end end
3779 //
3780 ::munmap(start, lp_start - start);
3781 ::munmap(lp_end, end - lp_end);
3782 return NULL;
3783 }
3784
3785 // Commit small-paged trailing area.
3786 if (lp_end != end) {
3787 result = ::mmap(lp_end, end - lp_end, prot,
3788 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
3789 -1, 0);
3790 if (result == MAP_FAILED) {
3791 ::munmap(start, lp_end - start);
3792 return NULL;
3793 }
3794 }
3795
3796 return start;
3797 }
3798
3799 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes,
3800 size_t alignment,
3801 char* req_addr,
3802 bool exec) {
3803 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
3804 assert(is_aligned(req_addr, alignment), "Must be");
3805 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be");
3806 assert(is_power_of_2(os::large_page_size()), "Must be");
3807 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes");
3808
3809 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) {
3810 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec);
3811 } else {
3812 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec);
3813 }
3814 }
3815
3816 char* os::reserve_memory_special(size_t bytes, size_t alignment,
3817 char* req_addr, bool exec) {
3818 assert(UseLargePages, "only for large pages");
3819
3820 char* addr;
3821 if (UseSHM) {
3822 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec);
3823 } else {
3824 assert(UseHugeTLBFS, "must be");
3825 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec);
3826 }
3827
3828 if (addr != NULL) {
3829 if (UseNUMAInterleaving) {
3830 numa_make_global(addr, bytes);
3831 }
3832
3833 // The memory is committed
3834 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
3835 }
3836
3837 return addr;
3838 }
3839
3840 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) {
3841 // detaching the SHM segment will also delete it, see reserve_memory_special_shm()
3842 return shmdt(base) == 0;
3843 }
3844
3845 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) {
3846 return pd_release_memory(base, bytes);
3847 }
3848
3849 bool os::release_memory_special(char* base, size_t bytes) {
3850 bool res;
3851 if (MemTracker::tracking_level() > NMT_minimal) {
3852 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
3853 res = os::Linux::release_memory_special_impl(base, bytes);
3854 if (res) {
3855 tkr.record((address)base, bytes);
3856 }
3857
3858 } else {
3859 res = os::Linux::release_memory_special_impl(base, bytes);
3860 }
3861 return res;
3862 }
3863
3864 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) {
3865 assert(UseLargePages, "only for large pages");
3866 bool res;
3867
3868 if (UseSHM) {
3869 res = os::Linux::release_memory_special_shm(base, bytes);
3870 } else {
3871 assert(UseHugeTLBFS, "must be");
3872 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes);
3873 }
3874 return res;
3875 }
3876
3877 size_t os::large_page_size() {
3878 return _large_page_size;
3879 }
3880
3881 // With SysV SHM the entire memory region must be allocated as shared
3882 // memory.
3883 // HugeTLBFS allows application to commit large page memory on demand.
3884 // However, when committing memory with HugeTLBFS fails, the region
3885 // that was supposed to be committed will lose the old reservation
3886 // and allow other threads to steal that memory region. Because of this
3887 // behavior we can't commit HugeTLBFS memory.
3888 bool os::can_commit_large_page_memory() {
3889 return UseTransparentHugePages;
3890 }
3891
3892 bool os::can_execute_large_page_memory() {
3893 return UseTransparentHugePages || UseHugeTLBFS;
3894 }
3895
3896 // Reserve memory at an arbitrary address, only if that area is
3897 // available (and not reserved for something else).
3898
3899 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
3900 const int max_tries = 10;
3901 char* base[max_tries];
3902 size_t size[max_tries];
3903 const size_t gap = 0x000000;
3904
3905 // Assert only that the size is a multiple of the page size, since
3906 // that's all that mmap requires, and since that's all we really know
3907 // about at this low abstraction level. If we need higher alignment,
3908 // we can either pass an alignment to this method or verify alignment
3909 // in one of the methods further up the call chain. See bug 5044738.
3910 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
3911
3912 // Repeatedly allocate blocks until the block is allocated at the
3913 // right spot.
3914
3915 // Linux mmap allows caller to pass an address as hint; give it a try first,
3916 // if kernel honors the hint then we can return immediately.
3917 char * addr = anon_mmap(requested_addr, bytes, false);
3918 if (addr == requested_addr) {
3919 return requested_addr;
3920 }
3921
3922 if (addr != NULL) {
3923 // mmap() is successful but it fails to reserve at the requested address
3924 anon_munmap(addr, bytes);
3925 }
3926
3927 int i;
3928 for (i = 0; i < max_tries; ++i) {
3929 base[i] = reserve_memory(bytes);
3930
3931 if (base[i] != NULL) {
3932 // Is this the block we wanted?
3933 if (base[i] == requested_addr) {
3934 size[i] = bytes;
3935 break;
3936 }
3937
3938 // Does this overlap the block we wanted? Give back the overlapped
3939 // parts and try again.
3940
3941 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i];
3942 if (top_overlap >= 0 && (size_t)top_overlap < bytes) {
3943 unmap_memory(base[i], top_overlap);
3944 base[i] += top_overlap;
3945 size[i] = bytes - top_overlap;
3946 } else {
3947 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr;
3948 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) {
3949 unmap_memory(requested_addr, bottom_overlap);
3950 size[i] = bytes - bottom_overlap;
3951 } else {
3952 size[i] = bytes;
3953 }
3954 }
3955 }
3956 }
3957
3958 // Give back the unused reserved pieces.
3959
3960 for (int j = 0; j < i; ++j) {
3961 if (base[j] != NULL) {
3962 unmap_memory(base[j], size[j]);
3963 }
3964 }
3965
3966 if (i < max_tries) {
3967 return requested_addr;
3968 } else {
3969 return NULL;
3970 }
3971 }
3972
3973 size_t os::read(int fd, void *buf, unsigned int nBytes) {
3974 return ::read(fd, buf, nBytes);
3975 }
3976
3977 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
3978 return ::pread(fd, buf, nBytes, offset);
3979 }
3980
3981 // Short sleep, direct OS call.
3982 //
3983 // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee
3984 // sched_yield(2) will actually give up the CPU:
3985 //
3986 // * Alone on this pariticular CPU, keeps running.
3987 // * Before the introduction of "skip_buddy" with "compat_yield" disabled
3988 // (pre 2.6.39).
3989 //
3990 // So calling this with 0 is an alternative.
3991 //
3992 void os::naked_short_sleep(jlong ms) {
3993 struct timespec req;
3994
3995 assert(ms < 1000, "Un-interruptable sleep, short time use only");
3996 req.tv_sec = 0;
3997 if (ms > 0) {
3998 req.tv_nsec = (ms % 1000) * 1000000;
3999 } else {
4000 req.tv_nsec = 1;
4001 }
4002
4003 nanosleep(&req, NULL);
4004
4005 return;
4006 }
4007
4008 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
4009 void os::infinite_sleep() {
4010 while (true) { // sleep forever ...
4011 ::sleep(100); // ... 100 seconds at a time
4012 }
4013 }
4014
4015 // Used to convert frequent JVM_Yield() to nops
4016 bool os::dont_yield() {
4017 return DontYieldALot;
4018 }
4019
4020 void os::naked_yield() {
4021 sched_yield();
4022 }
4023
4024 ////////////////////////////////////////////////////////////////////////////////
4025 // thread priority support
4026
4027 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER
4028 // only supports dynamic priority, static priority must be zero. For real-time
4029 // applications, Linux supports SCHED_RR which allows static priority (1-99).
4030 // However, for large multi-threaded applications, SCHED_RR is not only slower
4031 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
4032 // of 5 runs - Sep 2005).
4033 //
4034 // The following code actually changes the niceness of kernel-thread/LWP. It
4035 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
4036 // not the entire user process, and user level threads are 1:1 mapped to kernel
4037 // threads. It has always been the case, but could change in the future. For
4038 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
4039 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
4040
4041 int os::java_to_os_priority[CriticalPriority + 1] = {
4042 19, // 0 Entry should never be used
4043
4044 4, // 1 MinPriority
4045 3, // 2
4046 2, // 3
4047
4048 1, // 4
4049 0, // 5 NormPriority
4050 -1, // 6
4051
4052 -2, // 7
4053 -3, // 8
4054 -4, // 9 NearMaxPriority
4055
4056 -5, // 10 MaxPriority
4057
4058 -5 // 11 CriticalPriority
4059 };
4060
4061 static int prio_init() {
4062 if (ThreadPriorityPolicy == 1) {
4063 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
4064 // if effective uid is not root. Perhaps, a more elegant way of doing
4065 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
4066 if (geteuid() != 0) {
4067 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
4068 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux");
4069 }
4070 ThreadPriorityPolicy = 0;
4071 }
4072 }
4073 if (UseCriticalJavaThreadPriority) {
4074 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
4075 }
4076 return 0;
4077 }
4078
4079 OSReturn os::set_native_priority(Thread* thread, int newpri) {
4080 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
4081
4082 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
4083 return (ret == 0) ? OS_OK : OS_ERR;
4084 }
4085
4086 OSReturn os::get_native_priority(const Thread* const thread,
4087 int *priority_ptr) {
4088 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
4089 *priority_ptr = java_to_os_priority[NormPriority];
4090 return OS_OK;
4091 }
4092
4093 errno = 0;
4094 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
4095 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
4096 }
4097
4098 // Hint to the underlying OS that a task switch would not be good.
4099 // Void return because it's a hint and can fail.
4100 void os::hint_no_preempt() {}
4101
4102 ////////////////////////////////////////////////////////////////////////////////
4103 // suspend/resume support
4104
4105 // The low-level signal-based suspend/resume support is a remnant from the
4106 // old VM-suspension that used to be for java-suspension, safepoints etc,
4107 // within hotspot. Currently used by JFR's OSThreadSampler
4108 //
4109 // The remaining code is greatly simplified from the more general suspension
4110 // code that used to be used.
4111 //
4112 // The protocol is quite simple:
4113 // - suspend:
4114 // - sends a signal to the target thread
4115 // - polls the suspend state of the osthread using a yield loop
4116 // - target thread signal handler (SR_handler) sets suspend state
4117 // and blocks in sigsuspend until continued
4118 // - resume:
4119 // - sets target osthread state to continue
4120 // - sends signal to end the sigsuspend loop in the SR_handler
4121 //
4122 // Note that the SR_lock plays no role in this suspend/resume protocol,
4123 // but is checked for NULL in SR_handler as a thread termination indicator.
4124 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
4125 //
4126 // Note that resume_clear_context() and suspend_save_context() are needed
4127 // by SR_handler(), so that fetch_frame_from_ucontext() works,
4128 // which in part is used by:
4129 // - Forte Analyzer: AsyncGetCallTrace()
4130 // - StackBanging: get_frame_at_stack_banging_point()
4131
4132 static void resume_clear_context(OSThread *osthread) {
4133 osthread->set_ucontext(NULL);
4134 osthread->set_siginfo(NULL);
4135 }
4136
4137 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo,
4138 ucontext_t* context) {
4139 osthread->set_ucontext(context);
4140 osthread->set_siginfo(siginfo);
4141 }
4142
4143 // Handler function invoked when a thread's execution is suspended or
4144 // resumed. We have to be careful that only async-safe functions are
4145 // called here (Note: most pthread functions are not async safe and
4146 // should be avoided.)
4147 //
4148 // Note: sigwait() is a more natural fit than sigsuspend() from an
4149 // interface point of view, but sigwait() prevents the signal hander
4150 // from being run. libpthread would get very confused by not having
4151 // its signal handlers run and prevents sigwait()'s use with the
4152 // mutex granting granting signal.
4153 //
4154 // Currently only ever called on the VMThread and JavaThreads (PC sampling)
4155 //
4156 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
4157 // Save and restore errno to avoid confusing native code with EINTR
4158 // after sigsuspend.
4159 int old_errno = errno;
4160
4161 Thread* thread = Thread::current_or_null_safe();
4162 assert(thread != NULL, "Missing current thread in SR_handler");
4163
4164 // On some systems we have seen signal delivery get "stuck" until the signal
4165 // mask is changed as part of thread termination. Check that the current thread
4166 // has not already terminated (via SR_lock()) - else the following assertion
4167 // will fail because the thread is no longer a JavaThread as the ~JavaThread
4168 // destructor has completed.
4169
4170 if (thread->SR_lock() == NULL) {
4171 return;
4172 }
4173
4174 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
4175
4176 OSThread* osthread = thread->osthread();
4177
4178 os::SuspendResume::State current = osthread->sr.state();
4179 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
4180 suspend_save_context(osthread, siginfo, context);
4181
4182 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
4183 os::SuspendResume::State state = osthread->sr.suspended();
4184 if (state == os::SuspendResume::SR_SUSPENDED) {
4185 sigset_t suspend_set; // signals for sigsuspend()
4186 sigemptyset(&suspend_set);
4187 // get current set of blocked signals and unblock resume signal
4188 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
4189 sigdelset(&suspend_set, SR_signum);
4190
4191 sr_semaphore.signal();
4192 // wait here until we are resumed
4193 while (1) {
4194 sigsuspend(&suspend_set);
4195
4196 os::SuspendResume::State result = osthread->sr.running();
4197 if (result == os::SuspendResume::SR_RUNNING) {
4198 sr_semaphore.signal();
4199 break;
4200 }
4201 }
4202
4203 } else if (state == os::SuspendResume::SR_RUNNING) {
4204 // request was cancelled, continue
4205 } else {
4206 ShouldNotReachHere();
4207 }
4208
4209 resume_clear_context(osthread);
4210 } else if (current == os::SuspendResume::SR_RUNNING) {
4211 // request was cancelled, continue
4212 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
4213 // ignore
4214 } else {
4215 // ignore
4216 }
4217
4218 errno = old_errno;
4219 }
4220
4221 static int SR_initialize() {
4222 struct sigaction act;
4223 char *s;
4224
4225 // Get signal number to use for suspend/resume
4226 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
4227 int sig = ::strtol(s, 0, 10);
4228 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769.
4229 sig < NSIG) { // Must be legal signal and fit into sigflags[].
4230 SR_signum = sig;
4231 } else {
4232 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
4233 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
4234 }
4235 }
4236
4237 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
4238 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
4239
4240 sigemptyset(&SR_sigset);
4241 sigaddset(&SR_sigset, SR_signum);
4242
4243 // Set up signal handler for suspend/resume
4244 act.sa_flags = SA_RESTART|SA_SIGINFO;
4245 act.sa_handler = (void (*)(int)) SR_handler;
4246
4247 // SR_signum is blocked by default.
4248 // 4528190 - We also need to block pthread restart signal (32 on all
4249 // supported Linux platforms). Note that LinuxThreads need to block
4250 // this signal for all threads to work properly. So we don't have
4251 // to use hard-coded signal number when setting up the mask.
4252 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
4253
4254 if (sigaction(SR_signum, &act, 0) == -1) {
4255 return -1;
4256 }
4257
4258 // Save signal flag
4259 os::Linux::set_our_sigflags(SR_signum, act.sa_flags);
4260 return 0;
4261 }
4262
4263 static int sr_notify(OSThread* osthread) {
4264 int status = pthread_kill(osthread->pthread_id(), SR_signum);
4265 assert_status(status == 0, status, "pthread_kill");
4266 return status;
4267 }
4268
4269 // "Randomly" selected value for how long we want to spin
4270 // before bailing out on suspending a thread, also how often
4271 // we send a signal to a thread we want to resume
4272 static const int RANDOMLY_LARGE_INTEGER = 1000000;
4273 static const int RANDOMLY_LARGE_INTEGER2 = 100;
4274
4275 // returns true on success and false on error - really an error is fatal
4276 // but this seems the normal response to library errors
4277 static bool do_suspend(OSThread* osthread) {
4278 assert(osthread->sr.is_running(), "thread should be running");
4279 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
4280
4281 // mark as suspended and send signal
4282 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
4283 // failed to switch, state wasn't running?
4284 ShouldNotReachHere();
4285 return false;
4286 }
4287
4288 if (sr_notify(osthread) != 0) {
4289 ShouldNotReachHere();
4290 }
4291
4292 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
4293 while (true) {
4294 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
4295 break;
4296 } else {
4297 // timeout
4298 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
4299 if (cancelled == os::SuspendResume::SR_RUNNING) {
4300 return false;
4301 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
4302 // make sure that we consume the signal on the semaphore as well
4303 sr_semaphore.wait();
4304 break;
4305 } else {
4306 ShouldNotReachHere();
4307 return false;
4308 }
4309 }
4310 }
4311
4312 guarantee(osthread->sr.is_suspended(), "Must be suspended");
4313 return true;
4314 }
4315
4316 static void do_resume(OSThread* osthread) {
4317 assert(osthread->sr.is_suspended(), "thread should be suspended");
4318 assert(!sr_semaphore.trywait(), "invalid semaphore state");
4319
4320 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
4321 // failed to switch to WAKEUP_REQUEST
4322 ShouldNotReachHere();
4323 return;
4324 }
4325
4326 while (true) {
4327 if (sr_notify(osthread) == 0) {
4328 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
4329 if (osthread->sr.is_running()) {
4330 return;
4331 }
4332 }
4333 } else {
4334 ShouldNotReachHere();
4335 }
4336 }
4337
4338 guarantee(osthread->sr.is_running(), "Must be running!");
4339 }
4340
4341 ///////////////////////////////////////////////////////////////////////////////////
4342 // signal handling (except suspend/resume)
4343
4344 // This routine may be used by user applications as a "hook" to catch signals.
4345 // The user-defined signal handler must pass unrecognized signals to this
4346 // routine, and if it returns true (non-zero), then the signal handler must
4347 // return immediately. If the flag "abort_if_unrecognized" is true, then this
4348 // routine will never retun false (zero), but instead will execute a VM panic
4349 // routine kill the process.
4350 //
4351 // If this routine returns false, it is OK to call it again. This allows
4352 // the user-defined signal handler to perform checks either before or after
4353 // the VM performs its own checks. Naturally, the user code would be making
4354 // a serious error if it tried to handle an exception (such as a null check
4355 // or breakpoint) that the VM was generating for its own correct operation.
4356 //
4357 // This routine may recognize any of the following kinds of signals:
4358 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
4359 // It should be consulted by handlers for any of those signals.
4360 //
4361 // The caller of this routine must pass in the three arguments supplied
4362 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
4363 // field of the structure passed to sigaction(). This routine assumes that
4364 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
4365 //
4366 // Note that the VM will print warnings if it detects conflicting signal
4367 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
4368 //
4369 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo,
4370 siginfo_t* siginfo,
4371 void* ucontext,
4372 int abort_if_unrecognized);
4373
4374 void signalHandler(int sig, siginfo_t* info, void* uc) {
4375 assert(info != NULL && uc != NULL, "it must be old kernel");
4376 int orig_errno = errno; // Preserve errno value over signal handler.
4377 JVM_handle_linux_signal(sig, info, uc, true);
4378 errno = orig_errno;
4379 }
4380
4381
4382 // This boolean allows users to forward their own non-matching signals
4383 // to JVM_handle_linux_signal, harmlessly.
4384 bool os::Linux::signal_handlers_are_installed = false;
4385
4386 // For signal-chaining
4387 struct sigaction sigact[NSIG];
4388 uint64_t sigs = 0;
4389 #if (64 < NSIG-1)
4390 #error "Not all signals can be encoded in sigs. Adapt its type!"
4391 #endif
4392 bool os::Linux::libjsig_is_loaded = false;
4393 typedef struct sigaction *(*get_signal_t)(int);
4394 get_signal_t os::Linux::get_signal_action = NULL;
4395
4396 struct sigaction* os::Linux::get_chained_signal_action(int sig) {
4397 struct sigaction *actp = NULL;
4398
4399 if (libjsig_is_loaded) {
4400 // Retrieve the old signal handler from libjsig
4401 actp = (*get_signal_action)(sig);
4402 }
4403 if (actp == NULL) {
4404 // Retrieve the preinstalled signal handler from jvm
4405 actp = get_preinstalled_handler(sig);
4406 }
4407
4408 return actp;
4409 }
4410
4411 static bool call_chained_handler(struct sigaction *actp, int sig,
4412 siginfo_t *siginfo, void *context) {
4413 // Call the old signal handler
4414 if (actp->sa_handler == SIG_DFL) {
4415 // It's more reasonable to let jvm treat it as an unexpected exception
4416 // instead of taking the default action.
4417 return false;
4418 } else if (actp->sa_handler != SIG_IGN) {
4419 if ((actp->sa_flags & SA_NODEFER) == 0) {
4420 // automaticlly block the signal
4421 sigaddset(&(actp->sa_mask), sig);
4422 }
4423
4424 sa_handler_t hand = NULL;
4425 sa_sigaction_t sa = NULL;
4426 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
4427 // retrieve the chained handler
4428 if (siginfo_flag_set) {
4429 sa = actp->sa_sigaction;
4430 } else {
4431 hand = actp->sa_handler;
4432 }
4433
4434 if ((actp->sa_flags & SA_RESETHAND) != 0) {
4435 actp->sa_handler = SIG_DFL;
4436 }
4437
4438 // try to honor the signal mask
4439 sigset_t oset;
4440 sigemptyset(&oset);
4441 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
4442
4443 // call into the chained handler
4444 if (siginfo_flag_set) {
4445 (*sa)(sig, siginfo, context);
4446 } else {
4447 (*hand)(sig);
4448 }
4449
4450 // restore the signal mask
4451 pthread_sigmask(SIG_SETMASK, &oset, NULL);
4452 }
4453 // Tell jvm's signal handler the signal is taken care of.
4454 return true;
4455 }
4456
4457 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) {
4458 bool chained = false;
4459 // signal-chaining
4460 if (UseSignalChaining) {
4461 struct sigaction *actp = get_chained_signal_action(sig);
4462 if (actp != NULL) {
4463 chained = call_chained_handler(actp, sig, siginfo, context);
4464 }
4465 }
4466 return chained;
4467 }
4468
4469 struct sigaction* os::Linux::get_preinstalled_handler(int sig) {
4470 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) {
4471 return &sigact[sig];
4472 }
4473 return NULL;
4474 }
4475
4476 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
4477 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4478 sigact[sig] = oldAct;
4479 sigs |= (uint64_t)1 << (sig-1);
4480 }
4481
4482 // for diagnostic
4483 int sigflags[NSIG];
4484
4485 int os::Linux::get_our_sigflags(int sig) {
4486 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4487 return sigflags[sig];
4488 }
4489
4490 void os::Linux::set_our_sigflags(int sig, int flags) {
4491 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4492 if (sig > 0 && sig < NSIG) {
4493 sigflags[sig] = flags;
4494 }
4495 }
4496
4497 void os::Linux::set_signal_handler(int sig, bool set_installed) {
4498 // Check for overwrite.
4499 struct sigaction oldAct;
4500 sigaction(sig, (struct sigaction*)NULL, &oldAct);
4501
4502 void* oldhand = oldAct.sa_sigaction
4503 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4504 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4505 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
4506 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
4507 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
4508 if (AllowUserSignalHandlers || !set_installed) {
4509 // Do not overwrite; user takes responsibility to forward to us.
4510 return;
4511 } else if (UseSignalChaining) {
4512 // save the old handler in jvm
4513 save_preinstalled_handler(sig, oldAct);
4514 // libjsig also interposes the sigaction() call below and saves the
4515 // old sigaction on it own.
4516 } else {
4517 fatal("Encountered unexpected pre-existing sigaction handler "
4518 "%#lx for signal %d.", (long)oldhand, sig);
4519 }
4520 }
4521
4522 struct sigaction sigAct;
4523 sigfillset(&(sigAct.sa_mask));
4524 sigAct.sa_handler = SIG_DFL;
4525 if (!set_installed) {
4526 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4527 } else {
4528 sigAct.sa_sigaction = signalHandler;
4529 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4530 }
4531 // Save flags, which are set by ours
4532 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4533 sigflags[sig] = sigAct.sa_flags;
4534
4535 int ret = sigaction(sig, &sigAct, &oldAct);
4536 assert(ret == 0, "check");
4537
4538 void* oldhand2 = oldAct.sa_sigaction
4539 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4540 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4541 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
4542 }
4543
4544 // install signal handlers for signals that HotSpot needs to
4545 // handle in order to support Java-level exception handling.
4546
4547 void os::Linux::install_signal_handlers() {
4548 if (!signal_handlers_are_installed) {
4549 signal_handlers_are_installed = true;
4550
4551 // signal-chaining
4552 typedef void (*signal_setting_t)();
4553 signal_setting_t begin_signal_setting = NULL;
4554 signal_setting_t end_signal_setting = NULL;
4555 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4556 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
4557 if (begin_signal_setting != NULL) {
4558 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4559 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
4560 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
4561 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
4562 libjsig_is_loaded = true;
4563 assert(UseSignalChaining, "should enable signal-chaining");
4564 }
4565 if (libjsig_is_loaded) {
4566 // Tell libjsig jvm is setting signal handlers
4567 (*begin_signal_setting)();
4568 }
4569
4570 set_signal_handler(SIGSEGV, true);
4571 set_signal_handler(SIGPIPE, true);
4572 set_signal_handler(SIGBUS, true);
4573 set_signal_handler(SIGILL, true);
4574 set_signal_handler(SIGFPE, true);
4575 #if defined(PPC64)
4576 set_signal_handler(SIGTRAP, true);
4577 #endif
4578 set_signal_handler(SIGXFSZ, true);
4579
4580 if (libjsig_is_loaded) {
4581 // Tell libjsig jvm finishes setting signal handlers
4582 (*end_signal_setting)();
4583 }
4584
4585 // We don't activate signal checker if libjsig is in place, we trust ourselves
4586 // and if UserSignalHandler is installed all bets are off.
4587 // Log that signal checking is off only if -verbose:jni is specified.
4588 if (CheckJNICalls) {
4589 if (libjsig_is_loaded) {
4590 if (PrintJNIResolving) {
4591 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
4592 }
4593 check_signals = false;
4594 }
4595 if (AllowUserSignalHandlers) {
4596 if (PrintJNIResolving) {
4597 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
4598 }
4599 check_signals = false;
4600 }
4601 }
4602 }
4603 }
4604
4605 // This is the fastest way to get thread cpu time on Linux.
4606 // Returns cpu time (user+sys) for any thread, not only for current.
4607 // POSIX compliant clocks are implemented in the kernels 2.6.16+.
4608 // It might work on 2.6.10+ with a special kernel/glibc patch.
4609 // For reference, please, see IEEE Std 1003.1-2004:
4610 // http://www.unix.org/single_unix_specification
4611
4612 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) {
4613 struct timespec tp;
4614 int rc = os::Linux::clock_gettime(clockid, &tp);
4615 assert(rc == 0, "clock_gettime is expected to return 0 code");
4616
4617 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec;
4618 }
4619
4620 void os::Linux::initialize_os_info() {
4621 assert(_os_version == 0, "OS info already initialized");
4622
4623 struct utsname _uname;
4624
4625 uint32_t major;
4626 uint32_t minor;
4627 uint32_t fix;
4628
4629 int rc;
4630
4631 // Kernel version is unknown if
4632 // verification below fails.
4633 _os_version = 0x01000000;
4634
4635 rc = uname(&_uname);
4636 if (rc != -1) {
4637
4638 rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix);
4639 if (rc == 3) {
4640
4641 if (major < 256 && minor < 256 && fix < 256) {
4642 // Kernel version format is as expected,
4643 // set it overriding unknown state.
4644 _os_version = (major << 16) |
4645 (minor << 8 ) |
4646 (fix << 0 ) ;
4647 }
4648 }
4649 }
4650 }
4651
4652 uint32_t os::Linux::os_version() {
4653 assert(_os_version != 0, "not initialized");
4654 return _os_version & 0x00FFFFFF;
4655 }
4656
4657 bool os::Linux::os_version_is_known() {
4658 assert(_os_version != 0, "not initialized");
4659 return _os_version & 0x01000000 ? false : true;
4660 }
4661
4662 /////
4663 // glibc on Linux platform uses non-documented flag
4664 // to indicate, that some special sort of signal
4665 // trampoline is used.
4666 // We will never set this flag, and we should
4667 // ignore this flag in our diagnostic
4668 #ifdef SIGNIFICANT_SIGNAL_MASK
4669 #undef SIGNIFICANT_SIGNAL_MASK
4670 #endif
4671 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
4672
4673 static const char* get_signal_handler_name(address handler,
4674 char* buf, int buflen) {
4675 int offset = 0;
4676 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
4677 if (found) {
4678 // skip directory names
4679 const char *p1, *p2;
4680 p1 = buf;
4681 size_t len = strlen(os::file_separator());
4682 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
4683 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
4684 } else {
4685 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
4686 }
4687 return buf;
4688 }
4689
4690 static void print_signal_handler(outputStream* st, int sig,
4691 char* buf, size_t buflen) {
4692 struct sigaction sa;
4693
4694 sigaction(sig, NULL, &sa);
4695
4696 // See comment for SIGNIFICANT_SIGNAL_MASK define
4697 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4698
4699 st->print("%s: ", os::exception_name(sig, buf, buflen));
4700
4701 address handler = (sa.sa_flags & SA_SIGINFO)
4702 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
4703 : CAST_FROM_FN_PTR(address, sa.sa_handler);
4704
4705 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
4706 st->print("SIG_DFL");
4707 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
4708 st->print("SIG_IGN");
4709 } else {
4710 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
4711 }
4712
4713 st->print(", sa_mask[0]=");
4714 os::Posix::print_signal_set_short(st, &sa.sa_mask);
4715
4716 address rh = VMError::get_resetted_sighandler(sig);
4717 // May be, handler was resetted by VMError?
4718 if (rh != NULL) {
4719 handler = rh;
4720 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
4721 }
4722
4723 st->print(", sa_flags=");
4724 os::Posix::print_sa_flags(st, sa.sa_flags);
4725
4726 // Check: is it our handler?
4727 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
4728 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
4729 // It is our signal handler
4730 // check for flags, reset system-used one!
4731 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) {
4732 st->print(
4733 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
4734 os::Linux::get_our_sigflags(sig));
4735 }
4736 }
4737 st->cr();
4738 }
4739
4740
4741 #define DO_SIGNAL_CHECK(sig) \
4742 do { \
4743 if (!sigismember(&check_signal_done, sig)) { \
4744 os::Linux::check_signal_handler(sig); \
4745 } \
4746 } while (0)
4747
4748 // This method is a periodic task to check for misbehaving JNI applications
4749 // under CheckJNI, we can add any periodic checks here
4750
4751 void os::run_periodic_checks() {
4752 if (check_signals == false) return;
4753
4754 // SEGV and BUS if overridden could potentially prevent
4755 // generation of hs*.log in the event of a crash, debugging
4756 // such a case can be very challenging, so we absolutely
4757 // check the following for a good measure:
4758 DO_SIGNAL_CHECK(SIGSEGV);
4759 DO_SIGNAL_CHECK(SIGILL);
4760 DO_SIGNAL_CHECK(SIGFPE);
4761 DO_SIGNAL_CHECK(SIGBUS);
4762 DO_SIGNAL_CHECK(SIGPIPE);
4763 DO_SIGNAL_CHECK(SIGXFSZ);
4764 #if defined(PPC64)
4765 DO_SIGNAL_CHECK(SIGTRAP);
4766 #endif
4767
4768 // ReduceSignalUsage allows the user to override these handlers
4769 // see comments at the very top and jvm_solaris.h
4770 if (!ReduceSignalUsage) {
4771 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
4772 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
4773 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
4774 DO_SIGNAL_CHECK(BREAK_SIGNAL);
4775 }
4776
4777 DO_SIGNAL_CHECK(SR_signum);
4778 }
4779
4780 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
4781
4782 static os_sigaction_t os_sigaction = NULL;
4783
4784 void os::Linux::check_signal_handler(int sig) {
4785 char buf[O_BUFLEN];
4786 address jvmHandler = NULL;
4787
4788
4789 struct sigaction act;
4790 if (os_sigaction == NULL) {
4791 // only trust the default sigaction, in case it has been interposed
4792 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
4793 if (os_sigaction == NULL) return;
4794 }
4795
4796 os_sigaction(sig, (struct sigaction*)NULL, &act);
4797
4798
4799 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4800
4801 address thisHandler = (act.sa_flags & SA_SIGINFO)
4802 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
4803 : CAST_FROM_FN_PTR(address, act.sa_handler);
4804
4805
4806 switch (sig) {
4807 case SIGSEGV:
4808 case SIGBUS:
4809 case SIGFPE:
4810 case SIGPIPE:
4811 case SIGILL:
4812 case SIGXFSZ:
4813 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
4814 break;
4815
4816 case SHUTDOWN1_SIGNAL:
4817 case SHUTDOWN2_SIGNAL:
4818 case SHUTDOWN3_SIGNAL:
4819 case BREAK_SIGNAL:
4820 jvmHandler = (address)user_handler();
4821 break;
4822
4823 default:
4824 if (sig == SR_signum) {
4825 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
4826 } else {
4827 return;
4828 }
4829 break;
4830 }
4831
4832 if (thisHandler != jvmHandler) {
4833 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
4834 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
4835 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
4836 // No need to check this sig any longer
4837 sigaddset(&check_signal_done, sig);
4838 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
4839 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
4840 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
4841 exception_name(sig, buf, O_BUFLEN));
4842 }
4843 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) {
4844 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
4845 tty->print("expected:");
4846 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig));
4847 tty->cr();
4848 tty->print(" found:");
4849 os::Posix::print_sa_flags(tty, act.sa_flags);
4850 tty->cr();
4851 // No need to check this sig any longer
4852 sigaddset(&check_signal_done, sig);
4853 }
4854
4855 // Dump all the signal
4856 if (sigismember(&check_signal_done, sig)) {
4857 print_signal_handlers(tty, buf, O_BUFLEN);
4858 }
4859 }
4860
4861 extern void report_error(char* file_name, int line_no, char* title,
4862 char* format, ...);
4863
4864 // this is called _before_ the most of global arguments have been parsed
4865 void os::init(void) {
4866 char dummy; // used to get a guess on initial stack address
4867 // first_hrtime = gethrtime();
4868
4869 clock_tics_per_sec = sysconf(_SC_CLK_TCK);
4870
4871 init_random(1234567);
4872
4873 Linux::set_page_size(sysconf(_SC_PAGESIZE));
4874 if (Linux::page_size() == -1) {
4875 fatal("os_linux.cpp: os::init: sysconf failed (%s)",
4876 os::strerror(errno));
4877 }
4878 init_page_sizes((size_t) Linux::page_size());
4879
4880 Linux::initialize_system_info();
4881
4882 Linux::initialize_os_info();
4883
4884 // main_thread points to the aboriginal thread
4885 Linux::_main_thread = pthread_self();
4886
4887 Linux::clock_init();
4888 initial_time_count = javaTimeNanos();
4889
4890 // retrieve entry point for pthread_setname_np
4891 Linux::_pthread_setname_np =
4892 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np");
4893
4894 os::Posix::init();
4895 }
4896
4897 // To install functions for atexit system call
4898 extern "C" {
4899 static void perfMemory_exit_helper() {
4900 perfMemory_exit();
4901 }
4902 }
4903
4904 void os::pd_init_container_support() {
4905 OSContainer::init();
4906 }
4907
4908 // this is called _after_ the global arguments have been parsed
4909 jint os::init_2(void) {
4910
4911 os::Posix::init_2();
4912
4913 Linux::fast_thread_clock_init();
4914
4915 // Allocate a single page and mark it as readable for safepoint polling
4916 address polling_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
4917 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
4918
4919 os::set_polling_page(polling_page);
4920 log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
4921
4922 if (!UseMembar) {
4923 address mem_serialize_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
4924 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
4925 os::set_memory_serialize_page(mem_serialize_page);
4926 log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(mem_serialize_page));
4927 }
4928
4929 // initialize suspend/resume support - must do this before signal_sets_init()
4930 if (SR_initialize() != 0) {
4931 perror("SR_initialize failed");
4932 return JNI_ERR;
4933 }
4934
4935 Linux::signal_sets_init();
4936 Linux::install_signal_handlers();
4937
4938 // Check and sets minimum stack sizes against command line options
4939 if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
4940 return JNI_ERR;
4941 }
4942 Linux::capture_initial_stack(JavaThread::stack_size_at_create());
4943
4944 #if defined(IA32)
4945 workaround_expand_exec_shield_cs_limit();
4946 #endif
4947
4948 Linux::libpthread_init();
4949 Linux::sched_getcpu_init();
4950 log_info(os)("HotSpot is running with %s, %s",
4951 Linux::glibc_version(), Linux::libpthread_version());
4952
4953 if (UseNUMA) {
4954 if (!Linux::libnuma_init()) {
4955 UseNUMA = false;
4956 } else {
4957 if ((Linux::numa_max_node() < 1)) {
4958 // There's only one node(they start from 0), disable NUMA.
4959 UseNUMA = false;
4960 }
4961 }
4962 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way
4963 // we can make the adaptive lgrp chunk resizing work. If the user specified
4964 // both UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn and
4965 // disable adaptive resizing.
4966 if (UseNUMA && UseLargePages && !can_commit_large_page_memory()) {
4967 if (FLAG_IS_DEFAULT(UseNUMA)) {
4968 UseNUMA = false;
4969 } else {
4970 if (FLAG_IS_DEFAULT(UseLargePages) &&
4971 FLAG_IS_DEFAULT(UseSHM) &&
4972 FLAG_IS_DEFAULT(UseHugeTLBFS)) {
4973 UseLargePages = false;
4974 } else if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) {
4975 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)");
4976 UseAdaptiveSizePolicy = false;
4977 UseAdaptiveNUMAChunkSizing = false;
4978 }
4979 }
4980 }
4981 if (!UseNUMA && ForceNUMA) {
4982 UseNUMA = true;
4983 }
4984 }
4985
4986 if (MaxFDLimit) {
4987 // set the number of file descriptors to max. print out error
4988 // if getrlimit/setrlimit fails but continue regardless.
4989 struct rlimit nbr_files;
4990 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
4991 if (status != 0) {
4992 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
4993 } else {
4994 nbr_files.rlim_cur = nbr_files.rlim_max;
4995 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
4996 if (status != 0) {
4997 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
4998 }
4999 }
5000 }
5001
5002 // Initialize lock used to serialize thread creation (see os::create_thread)
5003 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false));
5004
5005 // at-exit methods are called in the reverse order of their registration.
5006 // atexit functions are called on return from main or as a result of a
5007 // call to exit(3C). There can be only 32 of these functions registered
5008 // and atexit() does not set errno.
5009
5010 if (PerfAllowAtExitRegistration) {
5011 // only register atexit functions if PerfAllowAtExitRegistration is set.
5012 // atexit functions can be delayed until process exit time, which
5013 // can be problematic for embedded VM situations. Embedded VMs should
5014 // call DestroyJavaVM() to assure that VM resources are released.
5015
5016 // note: perfMemory_exit_helper atexit function may be removed in
5017 // the future if the appropriate cleanup code can be added to the
5018 // VM_Exit VMOperation's doit method.
5019 if (atexit(perfMemory_exit_helper) != 0) {
5020 warning("os::init_2 atexit(perfMemory_exit_helper) failed");
5021 }
5022 }
5023
5024 // initialize thread priority policy
5025 prio_init();
5026
5027 return JNI_OK;
5028 }
5029
5030 // Mark the polling page as unreadable
5031 void os::make_polling_page_unreadable(void) {
5032 if (!guard_memory((char*)_polling_page, Linux::page_size())) {
5033 fatal("Could not disable polling page");
5034 }
5035 }
5036
5037 // Mark the polling page as readable
5038 void os::make_polling_page_readable(void) {
5039 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) {
5040 fatal("Could not enable polling page");
5041 }
5042 }
5043
5044 // older glibc versions don't have this macro (which expands to
5045 // an optimized bit-counting function) so we have to roll our own
5046 #ifndef CPU_COUNT
5047
5048 static int _cpu_count(const cpu_set_t* cpus) {
5049 int count = 0;
5050 // only look up to the number of configured processors
5051 for (int i = 0; i < os::processor_count(); i++) {
5052 if (CPU_ISSET(i, cpus)) {
5053 count++;
5054 }
5055 }
5056 return count;
5057 }
5058
5059 #define CPU_COUNT(cpus) _cpu_count(cpus)
5060
5061 #endif // CPU_COUNT
5062
5063 // Get the current number of available processors for this process.
5064 // This value can change at any time during a process's lifetime.
5065 // sched_getaffinity gives an accurate answer as it accounts for cpusets.
5066 // If it appears there may be more than 1024 processors then we do a
5067 // dynamic check - see 6515172 for details.
5068 // If anything goes wrong we fallback to returning the number of online
5069 // processors - which can be greater than the number available to the process.
5070 int os::Linux::active_processor_count() {
5071 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors
5072 cpu_set_t* cpus_p = &cpus;
5073 int cpus_size = sizeof(cpu_set_t);
5074
5075 int configured_cpus = os::processor_count(); // upper bound on available cpus
5076 int cpu_count = 0;
5077
5078 // old build platforms may not support dynamic cpu sets
5079 #ifdef CPU_ALLOC
5080
5081 // To enable easy testing of the dynamic path on different platforms we
5082 // introduce a diagnostic flag: UseCpuAllocPath
5083 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) {
5084 // kernel may use a mask bigger than cpu_set_t
5085 log_trace(os)("active_processor_count: using dynamic path %s"
5086 "- configured processors: %d",
5087 UseCpuAllocPath ? "(forced) " : "",
5088 configured_cpus);
5089 cpus_p = CPU_ALLOC(configured_cpus);
5090 if (cpus_p != NULL) {
5091 cpus_size = CPU_ALLOC_SIZE(configured_cpus);
5092 // zero it just to be safe
5093 CPU_ZERO_S(cpus_size, cpus_p);
5094 }
5095 else {
5096 // failed to allocate so fallback to online cpus
5097 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
5098 log_trace(os)("active_processor_count: "
5099 "CPU_ALLOC failed (%s) - using "
5100 "online processor count: %d",
5101 os::strerror(errno), online_cpus);
5102 return online_cpus;
5103 }
5104 }
5105 else {
5106 log_trace(os)("active_processor_count: using static path - configured processors: %d",
5107 configured_cpus);
5108 }
5109 #else // CPU_ALLOC
5110 // these stubs won't be executed
5111 #define CPU_COUNT_S(size, cpus) -1
5112 #define CPU_FREE(cpus)
5113
5114 log_trace(os)("active_processor_count: only static path available - configured processors: %d",
5115 configured_cpus);
5116 #endif // CPU_ALLOC
5117
5118 // pid 0 means the current thread - which we have to assume represents the process
5119 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) {
5120 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5121 cpu_count = CPU_COUNT_S(cpus_size, cpus_p);
5122 }
5123 else {
5124 cpu_count = CPU_COUNT(cpus_p);
5125 }
5126 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count);
5127 }
5128 else {
5129 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN);
5130 warning("sched_getaffinity failed (%s)- using online processor count (%d) "
5131 "which may exceed available processors", os::strerror(errno), cpu_count);
5132 }
5133
5134 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5135 CPU_FREE(cpus_p);
5136 }
5137
5138 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check");
5139 return cpu_count;
5140 }
5141
5142 // Determine the active processor count from one of
5143 // three different sources:
5144 //
5145 // 1. User option -XX:ActiveProcessorCount
5146 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN)
5147 // 3. extracted from cgroup cpu subsystem (shares and quotas)
5148 //
5149 // Option 1, if specified, will always override.
5150 // If the cgroup subsystem is active and configured, we
5151 // will return the min of the cgroup and option 2 results.
5152 // This is required since tools, such as numactl, that
5153 // alter cpu affinity do not update cgroup subsystem
5154 // cpuset configuration files.
5155 int os::active_processor_count() {
5156 // User has overridden the number of active processors
5157 if (ActiveProcessorCount > 0) {
5158 log_trace(os)("active_processor_count: "
5159 "active processor count set by user : %d",
5160 ActiveProcessorCount);
5161 return ActiveProcessorCount;
5162 }
5163
5164 int active_cpus;
5165 if (OSContainer::is_containerized()) {
5166 active_cpus = OSContainer::active_processor_count();
5167 log_trace(os)("active_processor_count: determined by OSContainer: %d",
5168 active_cpus);
5169 } else {
5170 active_cpus = os::Linux::active_processor_count();
5171 }
5172
5173 return active_cpus;
5174 }
5175
5176 void os::set_native_thread_name(const char *name) {
5177 if (Linux::_pthread_setname_np) {
5178 char buf [16]; // according to glibc manpage, 16 chars incl. '/0'
5179 snprintf(buf, sizeof(buf), "%s", name);
5180 buf[sizeof(buf) - 1] = '\0';
5181 const int rc = Linux::_pthread_setname_np(pthread_self(), buf);
5182 // ERANGE should not happen; all other errors should just be ignored.
5183 assert(rc != ERANGE, "pthread_setname_np failed");
5184 }
5185 }
5186
5187 bool os::distribute_processes(uint length, uint* distribution) {
5188 // Not yet implemented.
5189 return false;
5190 }
5191
5192 bool os::bind_to_processor(uint processor_id) {
5193 // Not yet implemented.
5194 return false;
5195 }
5196
5197 ///
5198
5199 void os::SuspendedThreadTask::internal_do_task() {
5200 if (do_suspend(_thread->osthread())) {
5201 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
5202 do_task(context);
5203 do_resume(_thread->osthread());
5204 }
5205 }
5206
5207 ////////////////////////////////////////////////////////////////////////////////
5208 // debug support
5209
5210 bool os::find(address addr, outputStream* st) {
5211 Dl_info dlinfo;
5212 memset(&dlinfo, 0, sizeof(dlinfo));
5213 if (dladdr(addr, &dlinfo) != 0) {
5214 st->print(PTR_FORMAT ": ", p2i(addr));
5215 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
5216 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname,
5217 p2i(addr) - p2i(dlinfo.dli_saddr));
5218 } else if (dlinfo.dli_fbase != NULL) {
5219 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase));
5220 } else {
5221 st->print("<absolute address>");
5222 }
5223 if (dlinfo.dli_fname != NULL) {
5224 st->print(" in %s", dlinfo.dli_fname);
5225 }
5226 if (dlinfo.dli_fbase != NULL) {
5227 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase));
5228 }
5229 st->cr();
5230
5231 if (Verbose) {
5232 // decode some bytes around the PC
5233 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
5234 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
5235 address lowest = (address) dlinfo.dli_sname;
5236 if (!lowest) lowest = (address) dlinfo.dli_fbase;
5237 if (begin < lowest) begin = lowest;
5238 Dl_info dlinfo2;
5239 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
5240 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
5241 end = (address) dlinfo2.dli_saddr;
5242 }
5243 Disassembler::decode(begin, end, st);
5244 }
5245 return true;
5246 }
5247 return false;
5248 }
5249
5250 ////////////////////////////////////////////////////////////////////////////////
5251 // misc
5252
5253 // This does not do anything on Linux. This is basically a hook for being
5254 // able to use structured exception handling (thread-local exception filters)
5255 // on, e.g., Win32.
5256 void
5257 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
5258 JavaCallArguments* args, Thread* thread) {
5259 f(value, method, args, thread);
5260 }
5261
5262 void os::print_statistics() {
5263 }
5264
5265 bool os::message_box(const char* title, const char* message) {
5266 int i;
5267 fdStream err(defaultStream::error_fd());
5268 for (i = 0; i < 78; i++) err.print_raw("=");
5269 err.cr();
5270 err.print_raw_cr(title);
5271 for (i = 0; i < 78; i++) err.print_raw("-");
5272 err.cr();
5273 err.print_raw_cr(message);
5274 for (i = 0; i < 78; i++) err.print_raw("=");
5275 err.cr();
5276
5277 char buf[16];
5278 // Prevent process from exiting upon "read error" without consuming all CPU
5279 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
5280
5281 return buf[0] == 'y' || buf[0] == 'Y';
5282 }
5283
5284 int os::stat(const char *path, struct stat *sbuf) {
5285 char pathbuf[MAX_PATH];
5286 if (strlen(path) > MAX_PATH - 1) {
5287 errno = ENAMETOOLONG;
5288 return -1;
5289 }
5290 os::native_path(strcpy(pathbuf, path));
5291 return ::stat(pathbuf, sbuf);
5292 }
5293
5294 // Is a (classpath) directory empty?
5295 bool os::dir_is_empty(const char* path) {
5296 DIR *dir = NULL;
5297 struct dirent *ptr;
5298
5299 dir = opendir(path);
5300 if (dir == NULL) return true;
5301
5302 // Scan the directory
5303 bool result = true;
5304 char buf[sizeof(struct dirent) + MAX_PATH];
5305 while (result && (ptr = ::readdir(dir)) != NULL) {
5306 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
5307 result = false;
5308 }
5309 }
5310 closedir(dir);
5311 return result;
5312 }
5313
5314 // This code originates from JDK's sysOpen and open64_w
5315 // from src/solaris/hpi/src/system_md.c
5316
5317 int os::open(const char *path, int oflag, int mode) {
5318 if (strlen(path) > MAX_PATH - 1) {
5319 errno = ENAMETOOLONG;
5320 return -1;
5321 }
5322
5323 // All file descriptors that are opened in the Java process and not
5324 // specifically destined for a subprocess should have the close-on-exec
5325 // flag set. If we don't set it, then careless 3rd party native code
5326 // might fork and exec without closing all appropriate file descriptors
5327 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in
5328 // turn might:
5329 //
5330 // - cause end-of-file to fail to be detected on some file
5331 // descriptors, resulting in mysterious hangs, or
5332 //
5333 // - might cause an fopen in the subprocess to fail on a system
5334 // suffering from bug 1085341.
5335 //
5336 // (Yes, the default setting of the close-on-exec flag is a Unix
5337 // design flaw)
5338 //
5339 // See:
5340 // 1085341: 32-bit stdio routines should support file descriptors >255
5341 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
5342 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
5343 //
5344 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open().
5345 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor
5346 // because it saves a system call and removes a small window where the flag
5347 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored
5348 // and we fall back to using FD_CLOEXEC (see below).
5349 #ifdef O_CLOEXEC
5350 oflag |= O_CLOEXEC;
5351 #endif
5352
5353 int fd = ::open64(path, oflag, mode);
5354 if (fd == -1) return -1;
5355
5356 //If the open succeeded, the file might still be a directory
5357 {
5358 struct stat64 buf64;
5359 int ret = ::fstat64(fd, &buf64);
5360 int st_mode = buf64.st_mode;
5361
5362 if (ret != -1) {
5363 if ((st_mode & S_IFMT) == S_IFDIR) {
5364 errno = EISDIR;
5365 ::close(fd);
5366 return -1;
5367 }
5368 } else {
5369 ::close(fd);
5370 return -1;
5371 }
5372 }
5373
5374 #ifdef FD_CLOEXEC
5375 // Validate that the use of the O_CLOEXEC flag on open above worked.
5376 // With recent kernels, we will perform this check exactly once.
5377 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
5378 if (!O_CLOEXEC_is_known_to_work) {
5379 int flags = ::fcntl(fd, F_GETFD);
5380 if (flags != -1) {
5381 if ((flags & FD_CLOEXEC) != 0)
5382 O_CLOEXEC_is_known_to_work = 1;
5383 else
5384 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
5385 }
5386 }
5387 #endif
5388
5389 return fd;
5390 }
5391
5392
5393 // create binary file, rewriting existing file if required
5394 int os::create_binary_file(const char* path, bool rewrite_existing) {
5395 int oflags = O_WRONLY | O_CREAT;
5396 if (!rewrite_existing) {
5397 oflags |= O_EXCL;
5398 }
5399 return ::open64(path, oflags, S_IREAD | S_IWRITE);
5400 }
5401
5402 // return current position of file pointer
5403 jlong os::current_file_offset(int fd) {
5404 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
5405 }
5406
5407 // move file pointer to the specified offset
5408 jlong os::seek_to_file_offset(int fd, jlong offset) {
5409 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
5410 }
5411
5412 // This code originates from JDK's sysAvailable
5413 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
5414
5415 int os::available(int fd, jlong *bytes) {
5416 jlong cur, end;
5417 int mode;
5418 struct stat64 buf64;
5419
5420 if (::fstat64(fd, &buf64) >= 0) {
5421 mode = buf64.st_mode;
5422 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
5423 int n;
5424 if (::ioctl(fd, FIONREAD, &n) >= 0) {
5425 *bytes = n;
5426 return 1;
5427 }
5428 }
5429 }
5430 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
5431 return 0;
5432 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
5433 return 0;
5434 } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
5435 return 0;
5436 }
5437 *bytes = end - cur;
5438 return 1;
5439 }
5440
5441 // Map a block of memory.
5442 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
5443 char *addr, size_t bytes, bool read_only,
5444 bool allow_exec) {
5445 int prot;
5446 int flags = MAP_PRIVATE;
5447
5448 if (read_only) {
5449 prot = PROT_READ;
5450 } else {
5451 prot = PROT_READ | PROT_WRITE;
5452 }
5453
5454 if (allow_exec) {
5455 prot |= PROT_EXEC;
5456 }
5457
5458 if (addr != NULL) {
5459 flags |= MAP_FIXED;
5460 }
5461
5462 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
5463 fd, file_offset);
5464 if (mapped_address == MAP_FAILED) {
5465 return NULL;
5466 }
5467 return mapped_address;
5468 }
5469
5470
5471 // Remap a block of memory.
5472 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
5473 char *addr, size_t bytes, bool read_only,
5474 bool allow_exec) {
5475 // same as map_memory() on this OS
5476 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
5477 allow_exec);
5478 }
5479
5480
5481 // Unmap a block of memory.
5482 bool os::pd_unmap_memory(char* addr, size_t bytes) {
5483 return munmap(addr, bytes) == 0;
5484 }
5485
5486 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time);
5487
5488 static clockid_t thread_cpu_clockid(Thread* thread) {
5489 pthread_t tid = thread->osthread()->pthread_id();
5490 clockid_t clockid;
5491
5492 // Get thread clockid
5493 int rc = os::Linux::pthread_getcpuclockid(tid, &clockid);
5494 assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code");
5495 return clockid;
5496 }
5497
5498 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
5499 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
5500 // of a thread.
5501 //
5502 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
5503 // the fast estimate available on the platform.
5504
5505 jlong os::current_thread_cpu_time() {
5506 if (os::Linux::supports_fast_thread_cpu_time()) {
5507 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5508 } else {
5509 // return user + sys since the cost is the same
5510 return slow_thread_cpu_time(Thread::current(), true /* user + sys */);
5511 }
5512 }
5513
5514 jlong os::thread_cpu_time(Thread* thread) {
5515 // consistent with what current_thread_cpu_time() returns
5516 if (os::Linux::supports_fast_thread_cpu_time()) {
5517 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread));
5518 } else {
5519 return slow_thread_cpu_time(thread, true /* user + sys */);
5520 }
5521 }
5522
5523 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
5524 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5525 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5526 } else {
5527 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time);
5528 }
5529 }
5530
5531 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5532 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5533 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread));
5534 } else {
5535 return slow_thread_cpu_time(thread, user_sys_cpu_time);
5536 }
5537 }
5538
5539 // -1 on error.
5540 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5541 pid_t tid = thread->osthread()->thread_id();
5542 char *s;
5543 char stat[2048];
5544 int statlen;
5545 char proc_name[64];
5546 int count;
5547 long sys_time, user_time;
5548 char cdummy;
5549 int idummy;
5550 long ldummy;
5551 FILE *fp;
5552
5553 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid);
5554 fp = fopen(proc_name, "r");
5555 if (fp == NULL) return -1;
5556 statlen = fread(stat, 1, 2047, fp);
5557 stat[statlen] = '\0';
5558 fclose(fp);
5559
5560 // Skip pid and the command string. Note that we could be dealing with
5561 // weird command names, e.g. user could decide to rename java launcher
5562 // to "java 1.4.2 :)", then the stat file would look like
5563 // 1234 (java 1.4.2 :)) R ... ...
5564 // We don't really need to know the command string, just find the last
5565 // occurrence of ")" and then start parsing from there. See bug 4726580.
5566 s = strrchr(stat, ')');
5567 if (s == NULL) return -1;
5568
5569 // Skip blank chars
5570 do { s++; } while (s && isspace(*s));
5571
5572 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu",
5573 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy,
5574 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy,
5575 &user_time, &sys_time);
5576 if (count != 13) return -1;
5577 if (user_sys_cpu_time) {
5578 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
5579 } else {
5580 return (jlong)user_time * (1000000000 / clock_tics_per_sec);
5581 }
5582 }
5583
5584 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5585 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5586 info_ptr->may_skip_backward = false; // elapsed time not wall time
5587 info_ptr->may_skip_forward = false; // elapsed time not wall time
5588 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5589 }
5590
5591 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5592 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5593 info_ptr->may_skip_backward = false; // elapsed time not wall time
5594 info_ptr->may_skip_forward = false; // elapsed time not wall time
5595 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5596 }
5597
5598 bool os::is_thread_cpu_time_supported() {
5599 return true;
5600 }
5601
5602 // System loadavg support. Returns -1 if load average cannot be obtained.
5603 // Linux doesn't yet have a (official) notion of processor sets,
5604 // so just return the system wide load average.
5605 int os::loadavg(double loadavg[], int nelem) {
5606 return ::getloadavg(loadavg, nelem);
5607 }
5608
5609 void os::pause() {
5610 char filename[MAX_PATH];
5611 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
5612 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
5613 } else {
5614 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
5615 }
5616
5617 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
5618 if (fd != -1) {
5619 struct stat buf;
5620 ::close(fd);
5621 while (::stat(filename, &buf) == 0) {
5622 (void)::poll(NULL, 0, 100);
5623 }
5624 } else {
5625 jio_fprintf(stderr,
5626 "Could not open pause file '%s', continuing immediately.\n", filename);
5627 }
5628 }
5629
5630 extern char** environ;
5631
5632 // Run the specified command in a separate process. Return its exit value,
5633 // or -1 on failure (e.g. can't fork a new process).
5634 // Unlike system(), this function can be called from signal handler. It
5635 // doesn't block SIGINT et al.
5636 int os::fork_and_exec(char* cmd) {
5637 const char * argv[4] = {"sh", "-c", cmd, NULL};
5638
5639 pid_t pid = fork();
5640
5641 if (pid < 0) {
5642 // fork failed
5643 return -1;
5644
5645 } else if (pid == 0) {
5646 // child process
5647
5648 execve("/bin/sh", (char* const*)argv, environ);
5649
5650 // execve failed
5651 _exit(-1);
5652
5653 } else {
5654 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
5655 // care about the actual exit code, for now.
5656
5657 int status;
5658
5659 // Wait for the child process to exit. This returns immediately if
5660 // the child has already exited. */
5661 while (waitpid(pid, &status, 0) < 0) {
5662 switch (errno) {
5663 case ECHILD: return 0;
5664 case EINTR: break;
5665 default: return -1;
5666 }
5667 }
5668
5669 if (WIFEXITED(status)) {
5670 // The child exited normally; get its exit code.
5671 return WEXITSTATUS(status);
5672 } else if (WIFSIGNALED(status)) {
5673 // The child exited because of a signal
5674 // The best value to return is 0x80 + signal number,
5675 // because that is what all Unix shells do, and because
5676 // it allows callers to distinguish between process exit and
5677 // process death by signal.
5678 return 0x80 + WTERMSIG(status);
5679 } else {
5680 // Unknown exit code; pass it through
5681 return status;
5682 }
5683 }
5684 }
5685
5686 // is_headless_jre()
5687 //
5688 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
5689 // in order to report if we are running in a headless jre
5690 //
5691 // Since JDK8 xawt/libmawt.so was moved into the same directory
5692 // as libawt.so, and renamed libawt_xawt.so
5693 //
5694 bool os::is_headless_jre() {
5695 struct stat statbuf;
5696 char buf[MAXPATHLEN];
5697 char libmawtpath[MAXPATHLEN];
5698 const char *xawtstr = "/xawt/libmawt.so";
5699 const char *new_xawtstr = "/libawt_xawt.so";
5700 char *p;
5701
5702 // Get path to libjvm.so
5703 os::jvm_path(buf, sizeof(buf));
5704
5705 // Get rid of libjvm.so
5706 p = strrchr(buf, '/');
5707 if (p == NULL) {
5708 return false;
5709 } else {
5710 *p = '\0';
5711 }
5712
5713 // Get rid of client or server
5714 p = strrchr(buf, '/');
5715 if (p == NULL) {
5716 return false;
5717 } else {
5718 *p = '\0';
5719 }
5720
5721 // check xawt/libmawt.so
5722 strcpy(libmawtpath, buf);
5723 strcat(libmawtpath, xawtstr);
5724 if (::stat(libmawtpath, &statbuf) == 0) return false;
5725
5726 // check libawt_xawt.so
5727 strcpy(libmawtpath, buf);
5728 strcat(libmawtpath, new_xawtstr);
5729 if (::stat(libmawtpath, &statbuf) == 0) return false;
5730
5731 return true;
5732 }
5733
5734 // Get the default path to the core file
5735 // Returns the length of the string
5736 int os::get_core_path(char* buffer, size_t bufferSize) {
5737 /*
5738 * Max length of /proc/sys/kernel/core_pattern is 128 characters.
5739 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
5740 */
5741 const int core_pattern_len = 129;
5742 char core_pattern[core_pattern_len] = {0};
5743
5744 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY);
5745 if (core_pattern_file == -1) {
5746 return -1;
5747 }
5748
5749 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len);
5750 ::close(core_pattern_file);
5751 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') {
5752 return -1;
5753 }
5754 if (core_pattern[ret-1] == '\n') {
5755 core_pattern[ret-1] = '\0';
5756 } else {
5757 core_pattern[ret] = '\0';
5758 }
5759
5760 char *pid_pos = strstr(core_pattern, "%p");
5761 int written;
5762
5763 if (core_pattern[0] == '/') {
5764 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern);
5765 } else {
5766 char cwd[PATH_MAX];
5767
5768 const char* p = get_current_directory(cwd, PATH_MAX);
5769 if (p == NULL) {
5770 return -1;
5771 }
5772
5773 if (core_pattern[0] == '|') {
5774 written = jio_snprintf(buffer, bufferSize,
5775 "\"%s\" (or dumping to %s/core.%d)",
5776 &core_pattern[1], p, current_process_id());
5777 } else {
5778 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern);
5779 }
5780 }
5781
5782 if (written < 0) {
5783 return -1;
5784 }
5785
5786 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) {
5787 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY);
5788
5789 if (core_uses_pid_file != -1) {
5790 char core_uses_pid = 0;
5791 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1);
5792 ::close(core_uses_pid_file);
5793
5794 if (core_uses_pid == '1') {
5795 jio_snprintf(buffer + written, bufferSize - written,
5796 ".%d", current_process_id());
5797 }
5798 }
5799 }
5800
5801 return strlen(buffer);
5802 }
5803
5804 bool os::start_debugging(char *buf, int buflen) {
5805 int len = (int)strlen(buf);
5806 char *p = &buf[len];
5807
5808 jio_snprintf(p, buflen-len,
5809 "\n\n"
5810 "Do you want to debug the problem?\n\n"
5811 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n"
5812 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
5813 "Otherwise, press RETURN to abort...",
5814 os::current_process_id(), os::current_process_id(),
5815 os::current_thread_id(), os::current_thread_id());
5816
5817 bool yes = os::message_box("Unexpected Error", buf);
5818
5819 if (yes) {
5820 // yes, user asked VM to launch debugger
5821 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d",
5822 os::current_process_id(), os::current_process_id());
5823
5824 os::fork_and_exec(buf);
5825 yes = false;
5826 }
5827 return yes;
5828 }
5829
5830
5831 // Java/Compiler thread:
5832 //
5833 // Low memory addresses
5834 // P0 +------------------------+
5835 // | |\ Java thread created by VM does not have glibc
5836 // | glibc guard page | - guard page, attached Java thread usually has
5837 // | |/ 1 glibc guard page.
5838 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
5839 // | |\
5840 // | HotSpot Guard Pages | - red, yellow and reserved pages
5841 // | |/
5842 // +------------------------+ JavaThread::stack_reserved_zone_base()
5843 // | |\
5844 // | Normal Stack | -
5845 // | |/
5846 // P2 +------------------------+ Thread::stack_base()
5847 //
5848 // Non-Java thread:
5849 //
5850 // Low memory addresses
5851 // P0 +------------------------+
5852 // | |\
5853 // | glibc guard page | - usually 1 page
5854 // | |/
5855 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
5856 // | |\
5857 // | Normal Stack | -
5858 // | |/
5859 // P2 +------------------------+ Thread::stack_base()
5860 //
5861 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size
5862 // returned from pthread_attr_getstack().
5863 // ** Due to NPTL implementation error, linux takes the glibc guard page out
5864 // of the stack size given in pthread_attr. We work around this for
5865 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.)
5866 //
5867 #ifndef ZERO
5868 static void current_stack_region(address * bottom, size_t * size) {
5869 if (os::Linux::is_initial_thread()) {
5870 // initial thread needs special handling because pthread_getattr_np()
5871 // may return bogus value.
5872 *bottom = os::Linux::initial_thread_stack_bottom();
5873 *size = os::Linux::initial_thread_stack_size();
5874 } else {
5875 pthread_attr_t attr;
5876
5877 int rslt = pthread_getattr_np(pthread_self(), &attr);
5878
5879 // JVM needs to know exact stack location, abort if it fails
5880 if (rslt != 0) {
5881 if (rslt == ENOMEM) {
5882 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
5883 } else {
5884 fatal("pthread_getattr_np failed with error = %d", rslt);
5885 }
5886 }
5887
5888 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
5889 fatal("Cannot locate current stack attributes!");
5890 }
5891
5892 // Work around NPTL stack guard error.
5893 size_t guard_size = 0;
5894 rslt = pthread_attr_getguardsize(&attr, &guard_size);
5895 if (rslt != 0) {
5896 fatal("pthread_attr_getguardsize failed with error = %d", rslt);
5897 }
5898 *bottom += guard_size;
5899 *size -= guard_size;
5900
5901 pthread_attr_destroy(&attr);
5902
5903 }
5904 assert(os::current_stack_pointer() >= *bottom &&
5905 os::current_stack_pointer() < *bottom + *size, "just checking");
5906 }
5907
5908 address os::current_stack_base() {
5909 address bottom;
5910 size_t size;
5911 current_stack_region(&bottom, &size);
5912 return (bottom + size);
5913 }
5914
5915 size_t os::current_stack_size() {
5916 // This stack size includes the usable stack and HotSpot guard pages
5917 // (for the threads that have Hotspot guard pages).
5918 address bottom;
5919 size_t size;
5920 current_stack_region(&bottom, &size);
5921 return size;
5922 }
5923 #endif
5924
5925 static inline struct timespec get_mtime(const char* filename) {
5926 struct stat st;
5927 int ret = os::stat(filename, &st);
5928 assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
5929 return st.st_mtim;
5930 }
5931
5932 int os::compare_file_modified_times(const char* file1, const char* file2) {
5933 struct timespec filetime1 = get_mtime(file1);
5934 struct timespec filetime2 = get_mtime(file2);
5935 int diff = filetime1.tv_sec - filetime2.tv_sec;
5936 if (diff == 0) {
5937 return filetime1.tv_nsec - filetime2.tv_nsec;
5938 }
5939 return diff;
5940 }
5941
5942 /////////////// Unit tests ///////////////
5943
5944 #ifndef PRODUCT
5945
5946 #define test_log(...) \
5947 do { \
5948 if (VerboseInternalVMTests) { \
5949 tty->print_cr(__VA_ARGS__); \
5950 tty->flush(); \
5951 } \
5952 } while (false)
5953
5954 class TestReserveMemorySpecial : AllStatic {
5955 public:
5956 static void small_page_write(void* addr, size_t size) {
5957 size_t page_size = os::vm_page_size();
5958
5959 char* end = (char*)addr + size;
5960 for (char* p = (char*)addr; p < end; p += page_size) {
5961 *p = 1;
5962 }
5963 }
5964
5965 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) {
5966 if (!UseHugeTLBFS) {
5967 return;
5968 }
5969
5970 test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size);
5971
5972 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false);
5973
5974 if (addr != NULL) {
5975 small_page_write(addr, size);
5976
5977 os::Linux::release_memory_special_huge_tlbfs(addr, size);
5978 }
5979 }
5980
5981 static void test_reserve_memory_special_huge_tlbfs_only() {
5982 if (!UseHugeTLBFS) {
5983 return;
5984 }
5985
5986 size_t lp = os::large_page_size();
5987
5988 for (size_t size = lp; size <= lp * 10; size += lp) {
5989 test_reserve_memory_special_huge_tlbfs_only(size);
5990 }
5991 }
5992
5993 static void test_reserve_memory_special_huge_tlbfs_mixed() {
5994 size_t lp = os::large_page_size();
5995 size_t ag = os::vm_allocation_granularity();
5996
5997 // sizes to test
5998 const size_t sizes[] = {
5999 lp, lp + ag, lp + lp / 2, lp * 2,
6000 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2,
6001 lp * 10, lp * 10 + lp / 2
6002 };
6003 const int num_sizes = sizeof(sizes) / sizeof(size_t);
6004
6005 // For each size/alignment combination, we test three scenarios:
6006 // 1) with req_addr == NULL
6007 // 2) with a non-null req_addr at which we expect to successfully allocate
6008 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we
6009 // expect the allocation to either fail or to ignore req_addr
6010
6011 // Pre-allocate two areas; they shall be as large as the largest allocation
6012 // and aligned to the largest alignment we will be testing.
6013 const size_t mapping_size = sizes[num_sizes - 1] * 2;
6014 char* const mapping1 = (char*) ::mmap(NULL, mapping_size,
6015 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6016 -1, 0);
6017 assert(mapping1 != MAP_FAILED, "should work");
6018
6019 char* const mapping2 = (char*) ::mmap(NULL, mapping_size,
6020 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6021 -1, 0);
6022 assert(mapping2 != MAP_FAILED, "should work");
6023
6024 // Unmap the first mapping, but leave the second mapping intact: the first
6025 // mapping will serve as a value for a "good" req_addr (case 2). The second
6026 // mapping, still intact, as "bad" req_addr (case 3).
6027 ::munmap(mapping1, mapping_size);
6028
6029 // Case 1
6030 test_log("%s, req_addr NULL:", __FUNCTION__);
6031 test_log("size align result");
6032
6033 for (int i = 0; i < num_sizes; i++) {
6034 const size_t size = sizes[i];
6035 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6036 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false);
6037 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s",
6038 size, alignment, p2i(p), (p != NULL ? "" : "(failed)"));
6039 if (p != NULL) {
6040 assert(is_aligned(p, alignment), "must be");
6041 small_page_write(p, size);
6042 os::Linux::release_memory_special_huge_tlbfs(p, size);
6043 }
6044 }
6045 }
6046
6047 // Case 2
6048 test_log("%s, req_addr non-NULL:", __FUNCTION__);
6049 test_log("size align req_addr result");
6050
6051 for (int i = 0; i < num_sizes; i++) {
6052 const size_t size = sizes[i];
6053 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6054 char* const req_addr = align_up(mapping1, alignment);
6055 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6056 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s",
6057 size, alignment, p2i(req_addr), p2i(p),
6058 ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)")));
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 test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__);
6069 test_log("size align req_addr result");
6070
6071 for (int i = 0; i < num_sizes; i++) {
6072 const size_t size = sizes[i];
6073 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6074 char* const req_addr = align_up(mapping2, alignment);
6075 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6076 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s",
6077 size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)")));
6078 // as the area around req_addr contains already existing mappings, the API should always
6079 // return NULL (as per contract, it cannot return another address)
6080 assert(p == NULL, "must be");
6081 }
6082 }
6083
6084 ::munmap(mapping2, mapping_size);
6085
6086 }
6087
6088 static void test_reserve_memory_special_huge_tlbfs() {
6089 if (!UseHugeTLBFS) {
6090 return;
6091 }
6092
6093 test_reserve_memory_special_huge_tlbfs_only();
6094 test_reserve_memory_special_huge_tlbfs_mixed();
6095 }
6096
6097 static void test_reserve_memory_special_shm(size_t size, size_t alignment) {
6098 if (!UseSHM) {
6099 return;
6100 }
6101
6102 test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment);
6103
6104 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false);
6105
6106 if (addr != NULL) {
6107 assert(is_aligned(addr, alignment), "Check");
6108 assert(is_aligned(addr, os::large_page_size()), "Check");
6109
6110 small_page_write(addr, size);
6111
6112 os::Linux::release_memory_special_shm(addr, size);
6113 }
6114 }
6115
6116 static void test_reserve_memory_special_shm() {
6117 size_t lp = os::large_page_size();
6118 size_t ag = os::vm_allocation_granularity();
6119
6120 for (size_t size = ag; size < lp * 3; size += ag) {
6121 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6122 test_reserve_memory_special_shm(size, alignment);
6123 }
6124 }
6125 }
6126
6127 static void test() {
6128 test_reserve_memory_special_huge_tlbfs();
6129 test_reserve_memory_special_shm();
6130 }
6131 };
6132
6133 void TestReserveMemorySpecial_test() {
6134 TestReserveMemorySpecial::test();
6135 }
6136
6137 #endif