1 /*
2 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 // no precompiled headers
26 #include "jvm.h"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "compiler/compileBroker.hpp"
33 #include "compiler/disassembler.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "logging/log.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "memory/filemap.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "os_linux.inline.hpp"
40 #include "os_share_linux.hpp"
41 #include "osContainer_linux.hpp"
42 #include "prims/jniFastGetField.hpp"
43 #include "prims/jvm_misc.hpp"
44 #include "runtime/arguments.hpp"
45 #include "runtime/atomic.hpp"
46 #include "runtime/extendedPC.hpp"
47 #include "runtime/globals.hpp"
48 #include "runtime/interfaceSupport.inline.hpp"
49 #include "runtime/init.hpp"
50 #include "runtime/java.hpp"
51 #include "runtime/javaCalls.hpp"
52 #include "runtime/mutexLocker.hpp"
53 #include "runtime/objectMonitor.hpp"
54 #include "runtime/orderAccess.hpp"
55 #include "runtime/osThread.hpp"
56 #include "runtime/perfMemory.hpp"
57 #include "runtime/sharedRuntime.hpp"
58 #include "runtime/statSampler.hpp"
59 #include "runtime/stubRoutines.hpp"
60 #include "runtime/thread.inline.hpp"
61 #include "runtime/threadCritical.hpp"
62 #include "runtime/threadSMR.hpp"
63 #include "runtime/timer.hpp"
64 #include "semaphore_posix.hpp"
65 #include "services/attachListener.hpp"
66 #include "services/memTracker.hpp"
67 #include "services/runtimeService.hpp"
68 #include "utilities/align.hpp"
69 #include "utilities/decoder.hpp"
70 #include "utilities/defaultStream.hpp"
71 #include "utilities/events.hpp"
72 #include "utilities/elfFile.hpp"
73 #include "utilities/growableArray.hpp"
74 #include "utilities/macros.hpp"
75 #include "utilities/vmError.hpp"
76
77 // put OS-includes here
78 # include <sys/types.h>
79 # include <sys/mman.h>
80 # include <sys/stat.h>
81 # include <sys/select.h>
82 # include <pthread.h>
83 # include <signal.h>
84 # include <errno.h>
85 # include <dlfcn.h>
86 # include <stdio.h>
87 # include <unistd.h>
88 # include <sys/resource.h>
89 # include <pthread.h>
90 # include <sys/stat.h>
91 # include <sys/time.h>
92 # include <sys/times.h>
93 # include <sys/utsname.h>
94 # include <sys/socket.h>
95 # include <sys/wait.h>
96 # include <pwd.h>
97 # include <poll.h>
98 # include <fcntl.h>
99 # include <string.h>
100 # include <syscall.h>
101 # include <sys/sysinfo.h>
102 # include <gnu/libc-version.h>
103 # include <sys/ipc.h>
104 # include <sys/shm.h>
105 # include <link.h>
106 # include <stdint.h>
107 # include <inttypes.h>
108 # include <sys/ioctl.h>
109
110 #ifndef _GNU_SOURCE
111 #define _GNU_SOURCE
112 #include <sched.h>
113 #undef _GNU_SOURCE
114 #else
115 #include <sched.h>
116 #endif
117
118 // if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling
119 // getrusage() is prepared to handle the associated failure.
120 #ifndef RUSAGE_THREAD
121 #define RUSAGE_THREAD (1) /* only the calling thread */
122 #endif
123
124 #define MAX_PATH (2 * K)
125
126 #define MAX_SECS 100000000
127
128 // for timer info max values which include all bits
129 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
130
131 #define LARGEPAGES_BIT (1 << 6)
132 #define DAX_SHARED_BIT (1 << 8)
133 ////////////////////////////////////////////////////////////////////////////////
134 // global variables
135 julong os::Linux::_physical_memory = 0;
136
137 address os::Linux::_initial_thread_stack_bottom = NULL;
138 uintptr_t os::Linux::_initial_thread_stack_size = 0;
139
140 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL;
141 int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL;
142 Mutex* os::Linux::_createThread_lock = NULL;
143 pthread_t os::Linux::_main_thread;
144 int os::Linux::_page_size = -1;
145 bool os::Linux::_supports_fast_thread_cpu_time = false;
146 uint32_t os::Linux::_os_version = 0;
147 const char * os::Linux::_glibc_version = NULL;
148 const char * os::Linux::_libpthread_version = NULL;
149
150 static jlong initial_time_count=0;
151
152 static int clock_tics_per_sec = 100;
153
154 // If the VM might have been created on the primordial thread, we need to resolve the
155 // primordial thread stack bounds and check if the current thread might be the
156 // primordial thread in places. If we know that the primordial thread is never used,
157 // such as when the VM was created by one of the standard java launchers, we can
158 // avoid this
159 static bool suppress_primordial_thread_resolution = false;
160
161 // For diagnostics to print a message once. see run_periodic_checks
162 static sigset_t check_signal_done;
163 static bool check_signals = true;
164
165 // Signal number used to suspend/resume a thread
166
167 // do not use any signal number less than SIGSEGV, see 4355769
168 static int SR_signum = SIGUSR2;
169 sigset_t SR_sigset;
170
171 // utility functions
172
173 static int SR_initialize();
174
175 julong os::available_memory() {
176 return Linux::available_memory();
177 }
178
179 julong os::Linux::available_memory() {
180 // values in struct sysinfo are "unsigned long"
181 struct sysinfo si;
182 julong avail_mem;
183
184 if (OSContainer::is_containerized()) {
185 jlong mem_limit, mem_usage;
186 if ((mem_limit = OSContainer::memory_limit_in_bytes()) < 1) {
187 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
188 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
189 }
190 if (mem_limit > 0 && (mem_usage = OSContainer::memory_usage_in_bytes()) < 1) {
191 log_debug(os, container)("container memory usage failed: " JLONG_FORMAT ", using host value", mem_usage);
192 }
193 if (mem_limit > 0 && mem_usage > 0 ) {
194 avail_mem = mem_limit > mem_usage ? (julong)mem_limit - (julong)mem_usage : 0;
195 log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem);
196 return avail_mem;
197 }
198 }
199
200 sysinfo(&si);
201 avail_mem = (julong)si.freeram * si.mem_unit;
202 log_trace(os)("available memory: " JULONG_FORMAT, avail_mem);
203 return avail_mem;
204 }
205
206 julong os::physical_memory() {
207 jlong phys_mem = 0;
208 if (OSContainer::is_containerized()) {
209 jlong mem_limit;
210 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) {
211 log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit);
212 return mem_limit;
213 }
214 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
215 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
216 }
217
218 phys_mem = Linux::physical_memory();
219 log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem);
220 return phys_mem;
221 }
222
223 // Return true if user is running as root.
224
225 bool os::have_special_privileges() {
226 static bool init = false;
227 static bool privileges = false;
228 if (!init) {
229 privileges = (getuid() != geteuid()) || (getgid() != getegid());
230 init = true;
231 }
232 return privileges;
233 }
234
235
236 #ifndef SYS_gettid
237 // i386: 224, ia64: 1105, amd64: 186, sparc 143
238 #ifdef __ia64__
239 #define SYS_gettid 1105
240 #else
241 #ifdef __i386__
242 #define SYS_gettid 224
243 #else
244 #ifdef __amd64__
245 #define SYS_gettid 186
246 #else
247 #ifdef __sparc__
248 #define SYS_gettid 143
249 #else
250 #error define gettid for the arch
251 #endif
252 #endif
253 #endif
254 #endif
255 #endif
256
257
258 // pid_t gettid()
259 //
260 // Returns the kernel thread id of the currently running thread. Kernel
261 // thread id is used to access /proc.
262 pid_t os::Linux::gettid() {
263 int rslt = syscall(SYS_gettid);
264 assert(rslt != -1, "must be."); // old linuxthreads implementation?
265 return (pid_t)rslt;
266 }
267
268 // Most versions of linux have a bug where the number of processors are
269 // determined by looking at the /proc file system. In a chroot environment,
270 // the system call returns 1.
271 static bool unsafe_chroot_detected = false;
272 static const char *unstable_chroot_error = "/proc file system not found.\n"
273 "Java may be unstable running multithreaded in a chroot "
274 "environment on Linux when /proc filesystem is not mounted.";
275
276 void os::Linux::initialize_system_info() {
277 set_processor_count(sysconf(_SC_NPROCESSORS_CONF));
278 if (processor_count() == 1) {
279 pid_t pid = os::Linux::gettid();
280 char fname[32];
281 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid);
282 FILE *fp = fopen(fname, "r");
283 if (fp == NULL) {
284 unsafe_chroot_detected = true;
285 } else {
286 fclose(fp);
287 }
288 }
289 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE);
290 assert(processor_count() > 0, "linux error");
291 }
292
293 void os::init_system_properties_values() {
294 // The next steps are taken in the product version:
295 //
296 // Obtain the JAVA_HOME value from the location of libjvm.so.
297 // This library should be located at:
298 // <JAVA_HOME>/lib/{client|server}/libjvm.so.
299 //
300 // If "/jre/lib/" appears at the right place in the path, then we
301 // assume libjvm.so is installed in a JDK and we use this path.
302 //
303 // Otherwise exit with message: "Could not create the Java virtual machine."
304 //
305 // The following extra steps are taken in the debugging version:
306 //
307 // If "/jre/lib/" does NOT appear at the right place in the path
308 // instead of exit check for $JAVA_HOME environment variable.
309 //
310 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
311 // then we append a fake suffix "hotspot/libjvm.so" to this path so
312 // it looks like libjvm.so is installed there
313 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
314 //
315 // Otherwise exit.
316 //
317 // Important note: if the location of libjvm.so changes this
318 // code needs to be changed accordingly.
319
320 // See ld(1):
321 // The linker uses the following search paths to locate required
322 // shared libraries:
323 // 1: ...
324 // ...
325 // 7: The default directories, normally /lib and /usr/lib.
326 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390)
327 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib"
328 #else
329 #define DEFAULT_LIBPATH "/lib:/usr/lib"
330 #endif
331
332 // Base path of extensions installed on the system.
333 #define SYS_EXT_DIR "/usr/java/packages"
334 #define EXTENSIONS_DIR "/lib/ext"
335
336 // Buffer that fits several sprintfs.
337 // Note that the space for the colon and the trailing null are provided
338 // by the nulls included by the sizeof operator.
339 const size_t bufsize =
340 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
341 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
342 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
343
344 // sysclasspath, java_home, dll_dir
345 {
346 char *pslash;
347 os::jvm_path(buf, bufsize);
348
349 // Found the full path to libjvm.so.
350 // Now cut the path to <java_home>/jre if we can.
351 pslash = strrchr(buf, '/');
352 if (pslash != NULL) {
353 *pslash = '\0'; // Get rid of /libjvm.so.
354 }
355 pslash = strrchr(buf, '/');
356 if (pslash != NULL) {
357 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
358 }
359 Arguments::set_dll_dir(buf);
360
361 if (pslash != NULL) {
362 pslash = strrchr(buf, '/');
363 if (pslash != NULL) {
364 *pslash = '\0'; // Get rid of /lib.
365 }
366 }
367 Arguments::set_java_home(buf);
368 if (!set_boot_path('/', ':')) {
369 vm_exit_during_initialization("Failed setting boot class path.", NULL);
370 }
371 }
372
373 // Where to look for native libraries.
374 //
375 // Note: Due to a legacy implementation, most of the library path
376 // is set in the launcher. This was to accomodate linking restrictions
377 // on legacy Linux implementations (which are no longer supported).
378 // Eventually, all the library path setting will be done here.
379 //
380 // However, to prevent the proliferation of improperly built native
381 // libraries, the new path component /usr/java/packages is added here.
382 // Eventually, all the library path setting will be done here.
383 {
384 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
385 // should always exist (until the legacy problem cited above is
386 // addressed).
387 const char *v = ::getenv("LD_LIBRARY_PATH");
388 const char *v_colon = ":";
389 if (v == NULL) { v = ""; v_colon = ""; }
390 // That's +1 for the colon and +1 for the trailing '\0'.
391 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
392 strlen(v) + 1 +
393 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1,
394 mtInternal);
395 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon);
396 Arguments::set_library_path(ld_library_path);
397 FREE_C_HEAP_ARRAY(char, ld_library_path);
398 }
399
400 // Extensions directories.
401 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
402 Arguments::set_ext_dirs(buf);
403
404 FREE_C_HEAP_ARRAY(char, buf);
405
406 #undef DEFAULT_LIBPATH
407 #undef SYS_EXT_DIR
408 #undef EXTENSIONS_DIR
409 }
410
411 ////////////////////////////////////////////////////////////////////////////////
412 // breakpoint support
413
414 void os::breakpoint() {
415 BREAKPOINT;
416 }
417
418 extern "C" void breakpoint() {
419 // use debugger to set breakpoint here
420 }
421
422 ////////////////////////////////////////////////////////////////////////////////
423 // signal support
424
425 debug_only(static bool signal_sets_initialized = false);
426 static sigset_t unblocked_sigs, vm_sigs;
427
428 void os::Linux::signal_sets_init() {
429 // Should also have an assertion stating we are still single-threaded.
430 assert(!signal_sets_initialized, "Already initialized");
431 // Fill in signals that are necessarily unblocked for all threads in
432 // the VM. Currently, we unblock the following signals:
433 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
434 // by -Xrs (=ReduceSignalUsage));
435 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
436 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
437 // the dispositions or masks wrt these signals.
438 // Programs embedding the VM that want to use the above signals for their
439 // own purposes must, at this time, use the "-Xrs" option to prevent
440 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
441 // (See bug 4345157, and other related bugs).
442 // In reality, though, unblocking these signals is really a nop, since
443 // these signals are not blocked by default.
444 sigemptyset(&unblocked_sigs);
445 sigaddset(&unblocked_sigs, SIGILL);
446 sigaddset(&unblocked_sigs, SIGSEGV);
447 sigaddset(&unblocked_sigs, SIGBUS);
448 sigaddset(&unblocked_sigs, SIGFPE);
449 #if defined(PPC64)
450 sigaddset(&unblocked_sigs, SIGTRAP);
451 #endif
452 sigaddset(&unblocked_sigs, SR_signum);
453
454 if (!ReduceSignalUsage) {
455 if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
456 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
457 }
458 if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
459 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
460 }
461 if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
462 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
463 }
464 }
465 // Fill in signals that are blocked by all but the VM thread.
466 sigemptyset(&vm_sigs);
467 if (!ReduceSignalUsage) {
468 sigaddset(&vm_sigs, BREAK_SIGNAL);
469 }
470 debug_only(signal_sets_initialized = true);
471
472 }
473
474 // These are signals that are unblocked while a thread is running Java.
475 // (For some reason, they get blocked by default.)
476 sigset_t* os::Linux::unblocked_signals() {
477 assert(signal_sets_initialized, "Not initialized");
478 return &unblocked_sigs;
479 }
480
481 // These are the signals that are blocked while a (non-VM) thread is
482 // running Java. Only the VM thread handles these signals.
483 sigset_t* os::Linux::vm_signals() {
484 assert(signal_sets_initialized, "Not initialized");
485 return &vm_sigs;
486 }
487
488 void os::Linux::hotspot_sigmask(Thread* thread) {
489
490 //Save caller's signal mask before setting VM signal mask
491 sigset_t caller_sigmask;
492 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
493
494 OSThread* osthread = thread->osthread();
495 osthread->set_caller_sigmask(caller_sigmask);
496
497 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL);
498
499 if (!ReduceSignalUsage) {
500 if (thread->is_VM_thread()) {
501 // Only the VM thread handles BREAK_SIGNAL ...
502 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
503 } else {
504 // ... all other threads block BREAK_SIGNAL
505 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
506 }
507 }
508 }
509
510 //////////////////////////////////////////////////////////////////////////////
511 // detecting pthread library
512
513 void os::Linux::libpthread_init() {
514 // Save glibc and pthread version strings.
515 #if !defined(_CS_GNU_LIBC_VERSION) || \
516 !defined(_CS_GNU_LIBPTHREAD_VERSION)
517 #error "glibc too old (< 2.3.2)"
518 #endif
519
520 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0);
521 assert(n > 0, "cannot retrieve glibc version");
522 char *str = (char *)malloc(n, mtInternal);
523 confstr(_CS_GNU_LIBC_VERSION, str, n);
524 os::Linux::set_glibc_version(str);
525
526 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
527 assert(n > 0, "cannot retrieve pthread version");
528 str = (char *)malloc(n, mtInternal);
529 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n);
530 os::Linux::set_libpthread_version(str);
531 }
532
533 /////////////////////////////////////////////////////////////////////////////
534 // thread stack expansion
535
536 // os::Linux::manually_expand_stack() takes care of expanding the thread
537 // stack. Note that this is normally not needed: pthread stacks allocate
538 // thread stack using mmap() without MAP_NORESERVE, so the stack is already
539 // committed. Therefore it is not necessary to expand the stack manually.
540 //
541 // Manually expanding the stack was historically needed on LinuxThreads
542 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays
543 // it is kept to deal with very rare corner cases:
544 //
545 // For one, user may run the VM on an own implementation of threads
546 // whose stacks are - like the old LinuxThreads - implemented using
547 // mmap(MAP_GROWSDOWN).
548 //
549 // Also, this coding may be needed if the VM is running on the primordial
550 // thread. Normally we avoid running on the primordial thread; however,
551 // user may still invoke the VM on the primordial thread.
552 //
553 // The following historical comment describes the details about running
554 // on a thread stack allocated with mmap(MAP_GROWSDOWN):
555
556
557 // Force Linux kernel to expand current thread stack. If "bottom" is close
558 // to the stack guard, caller should block all signals.
559 //
560 // MAP_GROWSDOWN:
561 // A special mmap() flag that is used to implement thread stacks. It tells
562 // kernel that the memory region should extend downwards when needed. This
563 // allows early versions of LinuxThreads to only mmap the first few pages
564 // when creating a new thread. Linux kernel will automatically expand thread
565 // stack as needed (on page faults).
566 //
567 // However, because the memory region of a MAP_GROWSDOWN stack can grow on
568 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN
569 // region, it's hard to tell if the fault is due to a legitimate stack
570 // access or because of reading/writing non-exist memory (e.g. buffer
571 // overrun). As a rule, if the fault happens below current stack pointer,
572 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the
573 // application (see Linux kernel fault.c).
574 //
575 // This Linux feature can cause SIGSEGV when VM bangs thread stack for
576 // stack overflow detection.
577 //
578 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do
579 // not use MAP_GROWSDOWN.
580 //
581 // To get around the problem and allow stack banging on Linux, we need to
582 // manually expand thread stack after receiving the SIGSEGV.
583 //
584 // There are two ways to expand thread stack to address "bottom", we used
585 // both of them in JVM before 1.5:
586 // 1. adjust stack pointer first so that it is below "bottom", and then
587 // touch "bottom"
588 // 2. mmap() the page in question
589 //
590 // Now alternate signal stack is gone, it's harder to use 2. For instance,
591 // if current sp is already near the lower end of page 101, and we need to
592 // call mmap() to map page 100, it is possible that part of the mmap() frame
593 // will be placed in page 100. When page 100 is mapped, it is zero-filled.
594 // That will destroy the mmap() frame and cause VM to crash.
595 //
596 // The following code works by adjusting sp first, then accessing the "bottom"
597 // page to force a page fault. Linux kernel will then automatically expand the
598 // stack mapping.
599 //
600 // _expand_stack_to() assumes its frame size is less than page size, which
601 // should always be true if the function is not inlined.
602
603 static void NOINLINE _expand_stack_to(address bottom) {
604 address sp;
605 size_t size;
606 volatile char *p;
607
608 // Adjust bottom to point to the largest address within the same page, it
609 // gives us a one-page buffer if alloca() allocates slightly more memory.
610 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size());
611 bottom += os::Linux::page_size() - 1;
612
613 // sp might be slightly above current stack pointer; if that's the case, we
614 // will alloca() a little more space than necessary, which is OK. Don't use
615 // os::current_stack_pointer(), as its result can be slightly below current
616 // stack pointer, causing us to not alloca enough to reach "bottom".
617 sp = (address)&sp;
618
619 if (sp > bottom) {
620 size = sp - bottom;
621 p = (volatile char *)alloca(size);
622 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?");
623 p[0] = '\0';
624 }
625 }
626
627 void os::Linux::expand_stack_to(address bottom) {
628 _expand_stack_to(bottom);
629 }
630
631 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) {
632 assert(t!=NULL, "just checking");
633 assert(t->osthread()->expanding_stack(), "expand should be set");
634 assert(t->stack_base() != NULL, "stack_base was not initialized");
635
636 if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) {
637 sigset_t mask_all, old_sigset;
638 sigfillset(&mask_all);
639 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset);
640 _expand_stack_to(addr);
641 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL);
642 return true;
643 }
644 return false;
645 }
646
647 //////////////////////////////////////////////////////////////////////////////
648 // create new thread
649
650 // Thread start routine for all newly created threads
651 static void *thread_native_entry(Thread *thread) {
652 // Try to randomize the cache line index of hot stack frames.
653 // This helps when threads of the same stack traces evict each other's
654 // cache lines. The threads can be either from the same JVM instance, or
655 // from different JVM instances. The benefit is especially true for
656 // processors with hyperthreading technology.
657 static int counter = 0;
658 int pid = os::current_process_id();
659 alloca(((pid ^ counter++) & 7) * 128);
660
661 thread->initialize_thread_current();
662
663 OSThread* osthread = thread->osthread();
664 Monitor* sync = osthread->startThread_lock();
665
666 osthread->set_thread_id(os::current_thread_id());
667
668 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
669 os::current_thread_id(), (uintx) pthread_self());
670
671 if (UseNUMA) {
672 int lgrp_id = os::numa_get_group_id();
673 if (lgrp_id != -1) {
674 thread->set_lgrp_id(lgrp_id);
675 }
676 }
677 // initialize signal mask for this thread
678 os::Linux::hotspot_sigmask(thread);
679
680 // initialize floating point control register
681 os::Linux::init_thread_fpu_state();
682
683 // handshaking with parent thread
684 {
685 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
686
687 // notify parent thread
688 osthread->set_state(INITIALIZED);
689 sync->notify_all();
690
691 // wait until os::start_thread()
692 while (osthread->get_state() == INITIALIZED) {
693 sync->wait(Mutex::_no_safepoint_check_flag);
694 }
695 }
696
697 // call one more level start routine
698 thread->run();
699
700 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
701 os::current_thread_id(), (uintx) pthread_self());
702
703 // If a thread has not deleted itself ("delete this") as part of its
704 // termination sequence, we have to ensure thread-local-storage is
705 // cleared before we actually terminate. No threads should ever be
706 // deleted asynchronously with respect to their termination.
707 if (Thread::current_or_null_safe() != NULL) {
708 assert(Thread::current_or_null_safe() == thread, "current thread is wrong");
709 thread->clear_thread_current();
710 }
711
712 return 0;
713 }
714
715 bool os::create_thread(Thread* thread, ThreadType thr_type,
716 size_t req_stack_size) {
717 assert(thread->osthread() == NULL, "caller responsible");
718
719 // Allocate the OSThread object
720 OSThread* osthread = new OSThread(NULL, NULL);
721 if (osthread == NULL) {
722 return false;
723 }
724
725 // set the correct thread state
726 osthread->set_thread_type(thr_type);
727
728 // Initial state is ALLOCATED but not INITIALIZED
729 osthread->set_state(ALLOCATED);
730
731 thread->set_osthread(osthread);
732
733 // init thread attributes
734 pthread_attr_t attr;
735 pthread_attr_init(&attr);
736 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
737
738 // Calculate stack size if it's not specified by caller.
739 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
740 // In the Linux NPTL pthread implementation the guard size mechanism
741 // is not implemented properly. The posix standard requires adding
742 // the size of the guard pages to the stack size, instead Linux
743 // takes the space out of 'stacksize'. Thus we adapt the requested
744 // stack_size by the size of the guard pages to mimick proper
745 // behaviour. However, be careful not to end up with a size
746 // of zero due to overflow. Don't add the guard page in that case.
747 size_t guard_size = os::Linux::default_guard_size(thr_type);
748 if (stack_size <= SIZE_MAX - guard_size) {
749 stack_size += guard_size;
750 }
751 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned");
752
753 int status = pthread_attr_setstacksize(&attr, stack_size);
754 assert_status(status == 0, status, "pthread_attr_setstacksize");
755
756 // Configure glibc guard page.
757 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type));
758
759 ThreadState state;
760
761 {
762 pthread_t tid;
763 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
764
765 char buf[64];
766 if (ret == 0) {
767 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
768 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
769 } else {
770 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
771 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
772 }
773
774 pthread_attr_destroy(&attr);
775
776 if (ret != 0) {
777 // Need to clean up stuff we've allocated so far
778 thread->set_osthread(NULL);
779 delete osthread;
780 return false;
781 }
782
783 // Store pthread info into the OSThread
784 osthread->set_pthread_id(tid);
785
786 // Wait until child thread is either initialized or aborted
787 {
788 Monitor* sync_with_child = osthread->startThread_lock();
789 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
790 while ((state = osthread->get_state()) == ALLOCATED) {
791 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
792 }
793 }
794 }
795
796 // Aborted due to thread limit being reached
797 if (state == ZOMBIE) {
798 thread->set_osthread(NULL);
799 delete osthread;
800 return false;
801 }
802
803 // The thread is returned suspended (in state INITIALIZED),
804 // and is started higher up in the call chain
805 assert(state == INITIALIZED, "race condition");
806 return true;
807 }
808
809 /////////////////////////////////////////////////////////////////////////////
810 // attach existing thread
811
812 // bootstrap the main thread
813 bool os::create_main_thread(JavaThread* thread) {
814 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread");
815 return create_attached_thread(thread);
816 }
817
818 bool os::create_attached_thread(JavaThread* thread) {
819 #ifdef ASSERT
820 thread->verify_not_published();
821 #endif
822
823 // Allocate the OSThread object
824 OSThread* osthread = new OSThread(NULL, NULL);
825
826 if (osthread == NULL) {
827 return false;
828 }
829
830 // Store pthread info into the OSThread
831 osthread->set_thread_id(os::Linux::gettid());
832 osthread->set_pthread_id(::pthread_self());
833
834 // initialize floating point control register
835 os::Linux::init_thread_fpu_state();
836
837 // Initial thread state is RUNNABLE
838 osthread->set_state(RUNNABLE);
839
840 thread->set_osthread(osthread);
841
842 if (UseNUMA) {
843 int lgrp_id = os::numa_get_group_id();
844 if (lgrp_id != -1) {
845 thread->set_lgrp_id(lgrp_id);
846 }
847 }
848
849 if (os::is_primordial_thread()) {
850 // If current thread is primordial thread, its stack is mapped on demand,
851 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map
852 // the entire stack region to avoid SEGV in stack banging.
853 // It is also useful to get around the heap-stack-gap problem on SuSE
854 // kernel (see 4821821 for details). We first expand stack to the top
855 // of yellow zone, then enable stack yellow zone (order is significant,
856 // enabling yellow zone first will crash JVM on SuSE Linux), so there
857 // is no gap between the last two virtual memory regions.
858
859 JavaThread *jt = (JavaThread *)thread;
860 address addr = jt->stack_reserved_zone_base();
861 assert(addr != NULL, "initialization problem?");
862 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled");
863
864 osthread->set_expanding_stack();
865 os::Linux::manually_expand_stack(jt, addr);
866 osthread->clear_expanding_stack();
867 }
868
869 // initialize signal mask for this thread
870 // and save the caller's signal mask
871 os::Linux::hotspot_sigmask(thread);
872
873 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
874 os::current_thread_id(), (uintx) pthread_self());
875
876 return true;
877 }
878
879 void os::pd_start_thread(Thread* thread) {
880 OSThread * osthread = thread->osthread();
881 assert(osthread->get_state() != INITIALIZED, "just checking");
882 Monitor* sync_with_child = osthread->startThread_lock();
883 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
884 sync_with_child->notify();
885 }
886
887 // Free Linux resources related to the OSThread
888 void os::free_thread(OSThread* osthread) {
889 assert(osthread != NULL, "osthread not set");
890
891 // We are told to free resources of the argument thread,
892 // but we can only really operate on the current thread.
893 assert(Thread::current()->osthread() == osthread,
894 "os::free_thread but not current thread");
895
896 #ifdef ASSERT
897 sigset_t current;
898 sigemptyset(¤t);
899 pthread_sigmask(SIG_SETMASK, NULL, ¤t);
900 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!");
901 #endif
902
903 // Restore caller's signal mask
904 sigset_t sigmask = osthread->caller_sigmask();
905 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
906
907 delete osthread;
908 }
909
910 //////////////////////////////////////////////////////////////////////////////
911 // primordial thread
912
913 // Check if current thread is the primordial thread, similar to Solaris thr_main.
914 bool os::is_primordial_thread(void) {
915 if (suppress_primordial_thread_resolution) {
916 return false;
917 }
918 char dummy;
919 // If called before init complete, thread stack bottom will be null.
920 // Can be called if fatal error occurs before initialization.
921 if (os::Linux::initial_thread_stack_bottom() == NULL) return false;
922 assert(os::Linux::initial_thread_stack_bottom() != NULL &&
923 os::Linux::initial_thread_stack_size() != 0,
924 "os::init did not locate primordial thread's stack region");
925 if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() &&
926 (address)&dummy < os::Linux::initial_thread_stack_bottom() +
927 os::Linux::initial_thread_stack_size()) {
928 return true;
929 } else {
930 return false;
931 }
932 }
933
934 // Find the virtual memory area that contains addr
935 static bool find_vma(address addr, address* vma_low, address* vma_high) {
936 FILE *fp = fopen("/proc/self/maps", "r");
937 if (fp) {
938 address low, high;
939 while (!feof(fp)) {
940 if (fscanf(fp, "%p-%p", &low, &high) == 2) {
941 if (low <= addr && addr < high) {
942 if (vma_low) *vma_low = low;
943 if (vma_high) *vma_high = high;
944 fclose(fp);
945 return true;
946 }
947 }
948 for (;;) {
949 int ch = fgetc(fp);
950 if (ch == EOF || ch == (int)'\n') break;
951 }
952 }
953 fclose(fp);
954 }
955 return false;
956 }
957
958 // Locate primordial thread stack. This special handling of primordial thread stack
959 // is needed because pthread_getattr_np() on most (all?) Linux distros returns
960 // bogus value for the primordial process thread. While the launcher has created
961 // the VM in a new thread since JDK 6, we still have to allow for the use of the
962 // JNI invocation API from a primordial thread.
963 void os::Linux::capture_initial_stack(size_t max_size) {
964
965 // max_size is either 0 (which means accept OS default for thread stacks) or
966 // a user-specified value known to be at least the minimum needed. If we
967 // are actually on the primordial thread we can make it appear that we have a
968 // smaller max_size stack by inserting the guard pages at that location. But we
969 // cannot do anything to emulate a larger stack than what has been provided by
970 // the OS or threading library. In fact if we try to use a stack greater than
971 // what is set by rlimit then we will crash the hosting process.
972
973 // Maximum stack size is the easy part, get it from RLIMIT_STACK.
974 // If this is "unlimited" then it will be a huge value.
975 struct rlimit rlim;
976 getrlimit(RLIMIT_STACK, &rlim);
977 size_t stack_size = rlim.rlim_cur;
978
979 // 6308388: a bug in ld.so will relocate its own .data section to the
980 // lower end of primordial stack; reduce ulimit -s value a little bit
981 // so we won't install guard page on ld.so's data section.
982 // But ensure we don't underflow the stack size - allow 1 page spare
983 if (stack_size >= (size_t)(3 * page_size())) {
984 stack_size -= 2 * page_size();
985 }
986
987 // Try to figure out where the stack base (top) is. This is harder.
988 //
989 // When an application is started, glibc saves the initial stack pointer in
990 // a global variable "__libc_stack_end", which is then used by system
991 // libraries. __libc_stack_end should be pretty close to stack top. The
992 // variable is available since the very early days. However, because it is
993 // a private interface, it could disappear in the future.
994 //
995 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar
996 // to __libc_stack_end, it is very close to stack top, but isn't the real
997 // stack top. Note that /proc may not exist if VM is running as a chroot
998 // program, so reading /proc/<pid>/stat could fail. Also the contents of
999 // /proc/<pid>/stat could change in the future (though unlikely).
1000 //
1001 // We try __libc_stack_end first. If that doesn't work, look for
1002 // /proc/<pid>/stat. If neither of them works, we use current stack pointer
1003 // as a hint, which should work well in most cases.
1004
1005 uintptr_t stack_start;
1006
1007 // try __libc_stack_end first
1008 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end");
1009 if (p && *p) {
1010 stack_start = *p;
1011 } else {
1012 // see if we can get the start_stack field from /proc/self/stat
1013 FILE *fp;
1014 int pid;
1015 char state;
1016 int ppid;
1017 int pgrp;
1018 int session;
1019 int nr;
1020 int tpgrp;
1021 unsigned long flags;
1022 unsigned long minflt;
1023 unsigned long cminflt;
1024 unsigned long majflt;
1025 unsigned long cmajflt;
1026 unsigned long utime;
1027 unsigned long stime;
1028 long cutime;
1029 long cstime;
1030 long prio;
1031 long nice;
1032 long junk;
1033 long it_real;
1034 uintptr_t start;
1035 uintptr_t vsize;
1036 intptr_t rss;
1037 uintptr_t rsslim;
1038 uintptr_t scodes;
1039 uintptr_t ecode;
1040 int i;
1041
1042 // Figure what the primordial thread stack base is. Code is inspired
1043 // by email from Hans Boehm. /proc/self/stat begins with current pid,
1044 // followed by command name surrounded by parentheses, state, etc.
1045 char stat[2048];
1046 int statlen;
1047
1048 fp = fopen("/proc/self/stat", "r");
1049 if (fp) {
1050 statlen = fread(stat, 1, 2047, fp);
1051 stat[statlen] = '\0';
1052 fclose(fp);
1053
1054 // Skip pid and the command string. Note that we could be dealing with
1055 // weird command names, e.g. user could decide to rename java launcher
1056 // to "java 1.4.2 :)", then the stat file would look like
1057 // 1234 (java 1.4.2 :)) R ... ...
1058 // We don't really need to know the command string, just find the last
1059 // occurrence of ")" and then start parsing from there. See bug 4726580.
1060 char * s = strrchr(stat, ')');
1061
1062 i = 0;
1063 if (s) {
1064 // Skip blank chars
1065 do { s++; } while (s && isspace(*s));
1066
1067 #define _UFM UINTX_FORMAT
1068 #define _DFM INTX_FORMAT
1069
1070 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2
1071 // 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8
1072 i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM,
1073 &state, // 3 %c
1074 &ppid, // 4 %d
1075 &pgrp, // 5 %d
1076 &session, // 6 %d
1077 &nr, // 7 %d
1078 &tpgrp, // 8 %d
1079 &flags, // 9 %lu
1080 &minflt, // 10 %lu
1081 &cminflt, // 11 %lu
1082 &majflt, // 12 %lu
1083 &cmajflt, // 13 %lu
1084 &utime, // 14 %lu
1085 &stime, // 15 %lu
1086 &cutime, // 16 %ld
1087 &cstime, // 17 %ld
1088 &prio, // 18 %ld
1089 &nice, // 19 %ld
1090 &junk, // 20 %ld
1091 &it_real, // 21 %ld
1092 &start, // 22 UINTX_FORMAT
1093 &vsize, // 23 UINTX_FORMAT
1094 &rss, // 24 INTX_FORMAT
1095 &rsslim, // 25 UINTX_FORMAT
1096 &scodes, // 26 UINTX_FORMAT
1097 &ecode, // 27 UINTX_FORMAT
1098 &stack_start); // 28 UINTX_FORMAT
1099 }
1100
1101 #undef _UFM
1102 #undef _DFM
1103
1104 if (i != 28 - 2) {
1105 assert(false, "Bad conversion from /proc/self/stat");
1106 // product mode - assume we are the primordial thread, good luck in the
1107 // embedded case.
1108 warning("Can't detect primordial thread stack location - bad conversion");
1109 stack_start = (uintptr_t) &rlim;
1110 }
1111 } else {
1112 // For some reason we can't open /proc/self/stat (for example, running on
1113 // FreeBSD with a Linux emulator, or inside chroot), this should work for
1114 // most cases, so don't abort:
1115 warning("Can't detect primordial thread stack location - no /proc/self/stat");
1116 stack_start = (uintptr_t) &rlim;
1117 }
1118 }
1119
1120 // Now we have a pointer (stack_start) very close to the stack top, the
1121 // next thing to do is to figure out the exact location of stack top. We
1122 // can find out the virtual memory area that contains stack_start by
1123 // reading /proc/self/maps, it should be the last vma in /proc/self/maps,
1124 // and its upper limit is the real stack top. (again, this would fail if
1125 // running inside chroot, because /proc may not exist.)
1126
1127 uintptr_t stack_top;
1128 address low, high;
1129 if (find_vma((address)stack_start, &low, &high)) {
1130 // success, "high" is the true stack top. (ignore "low", because initial
1131 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.)
1132 stack_top = (uintptr_t)high;
1133 } else {
1134 // failed, likely because /proc/self/maps does not exist
1135 warning("Can't detect primordial thread stack location - find_vma failed");
1136 // best effort: stack_start is normally within a few pages below the real
1137 // stack top, use it as stack top, and reduce stack size so we won't put
1138 // guard page outside stack.
1139 stack_top = stack_start;
1140 stack_size -= 16 * page_size();
1141 }
1142
1143 // stack_top could be partially down the page so align it
1144 stack_top = align_up(stack_top, page_size());
1145
1146 // Allowed stack value is minimum of max_size and what we derived from rlimit
1147 if (max_size > 0) {
1148 _initial_thread_stack_size = MIN2(max_size, stack_size);
1149 } else {
1150 // Accept the rlimit max, but if stack is unlimited then it will be huge, so
1151 // clamp it at 8MB as we do on Solaris
1152 _initial_thread_stack_size = MIN2(stack_size, 8*M);
1153 }
1154 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size());
1155 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size;
1156
1157 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!");
1158
1159 if (log_is_enabled(Info, os, thread)) {
1160 // See if we seem to be on primordial process thread
1161 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) &&
1162 uintptr_t(&rlim) < stack_top;
1163
1164 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: "
1165 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT,
1166 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K,
1167 stack_top, intptr_t(_initial_thread_stack_bottom));
1168 }
1169 }
1170
1171 ////////////////////////////////////////////////////////////////////////////////
1172 // time support
1173
1174 #ifndef SUPPORTS_CLOCK_MONOTONIC
1175 #error "Build platform doesn't support clock_gettime and related functionality"
1176 #endif
1177
1178 // Time since start-up in seconds to a fine granularity.
1179 // Used by VMSelfDestructTimer and the MemProfiler.
1180 double os::elapsedTime() {
1181
1182 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
1183 }
1184
1185 jlong os::elapsed_counter() {
1186 return javaTimeNanos() - initial_time_count;
1187 }
1188
1189 jlong os::elapsed_frequency() {
1190 return NANOSECS_PER_SEC; // nanosecond resolution
1191 }
1192
1193 bool os::supports_vtime() { return true; }
1194 bool os::enable_vtime() { return false; }
1195 bool os::vtime_enabled() { return false; }
1196
1197 double os::elapsedVTime() {
1198 struct rusage usage;
1199 int retval = getrusage(RUSAGE_THREAD, &usage);
1200 if (retval == 0) {
1201 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);
1202 } else {
1203 // better than nothing, but not much
1204 return elapsedTime();
1205 }
1206 }
1207
1208 jlong os::javaTimeMillis() {
1209 timeval time;
1210 int status = gettimeofday(&time, NULL);
1211 assert(status != -1, "linux error");
1212 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
1213 }
1214
1215 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
1216 timeval time;
1217 int status = gettimeofday(&time, NULL);
1218 assert(status != -1, "linux error");
1219 seconds = jlong(time.tv_sec);
1220 nanos = jlong(time.tv_usec) * 1000;
1221 }
1222
1223 void os::Linux::fast_thread_clock_init() {
1224 if (!UseLinuxPosixThreadCPUClocks) {
1225 return;
1226 }
1227 clockid_t clockid;
1228 struct timespec tp;
1229 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) =
1230 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid");
1231
1232 // Switch to using fast clocks for thread cpu time if
1233 // the clock_getres() returns 0 error code.
1234 // Note, that some kernels may support the current thread
1235 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks
1236 // returned by the pthread_getcpuclockid().
1237 // If the fast Posix clocks are supported then the clock_getres()
1238 // must return at least tp.tv_sec == 0 which means a resolution
1239 // better than 1 sec. This is extra check for reliability.
1240
1241 if (pthread_getcpuclockid_func &&
1242 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 &&
1243 os::Posix::clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) {
1244 _supports_fast_thread_cpu_time = true;
1245 _pthread_getcpuclockid = pthread_getcpuclockid_func;
1246 }
1247 }
1248
1249 jlong os::javaTimeNanos() {
1250 if (os::supports_monotonic_clock()) {
1251 struct timespec tp;
1252 int status = os::Posix::clock_gettime(CLOCK_MONOTONIC, &tp);
1253 assert(status == 0, "gettime error");
1254 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1255 return result;
1256 } else {
1257 timeval time;
1258 int status = gettimeofday(&time, NULL);
1259 assert(status != -1, "linux error");
1260 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1261 return 1000 * usecs;
1262 }
1263 }
1264
1265 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1266 if (os::supports_monotonic_clock()) {
1267 info_ptr->max_value = ALL_64_BITS;
1268
1269 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1270 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1271 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1272 } else {
1273 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1274 info_ptr->max_value = ALL_64_BITS;
1275
1276 // gettimeofday is a real time clock so it skips
1277 info_ptr->may_skip_backward = true;
1278 info_ptr->may_skip_forward = true;
1279 }
1280
1281 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1282 }
1283
1284 // Return the real, user, and system times in seconds from an
1285 // arbitrary fixed point in the past.
1286 bool os::getTimesSecs(double* process_real_time,
1287 double* process_user_time,
1288 double* process_system_time) {
1289 struct tms ticks;
1290 clock_t real_ticks = times(&ticks);
1291
1292 if (real_ticks == (clock_t) (-1)) {
1293 return false;
1294 } else {
1295 double ticks_per_second = (double) clock_tics_per_sec;
1296 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1297 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1298 *process_real_time = ((double) real_ticks) / ticks_per_second;
1299
1300 return true;
1301 }
1302 }
1303
1304
1305 char * os::local_time_string(char *buf, size_t buflen) {
1306 struct tm t;
1307 time_t long_time;
1308 time(&long_time);
1309 localtime_r(&long_time, &t);
1310 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1311 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1312 t.tm_hour, t.tm_min, t.tm_sec);
1313 return buf;
1314 }
1315
1316 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1317 return localtime_r(clock, res);
1318 }
1319
1320 ////////////////////////////////////////////////////////////////////////////////
1321 // runtime exit support
1322
1323 // Note: os::shutdown() might be called very early during initialization, or
1324 // called from signal handler. Before adding something to os::shutdown(), make
1325 // sure it is async-safe and can handle partially initialized VM.
1326 void os::shutdown() {
1327
1328 // allow PerfMemory to attempt cleanup of any persistent resources
1329 perfMemory_exit();
1330
1331 // needs to remove object in file system
1332 AttachListener::abort();
1333
1334 // flush buffered output, finish log files
1335 ostream_abort();
1336
1337 // Check for abort hook
1338 abort_hook_t abort_hook = Arguments::abort_hook();
1339 if (abort_hook != NULL) {
1340 abort_hook();
1341 }
1342
1343 }
1344
1345 // Note: os::abort() might be called very early during initialization, or
1346 // called from signal handler. Before adding something to os::abort(), make
1347 // sure it is async-safe and can handle partially initialized VM.
1348 void os::abort(bool dump_core, void* siginfo, const void* context) {
1349 os::shutdown();
1350 if (dump_core) {
1351 #ifndef PRODUCT
1352 fdStream out(defaultStream::output_fd());
1353 out.print_raw("Current thread is ");
1354 char buf[16];
1355 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1356 out.print_raw_cr(buf);
1357 out.print_raw_cr("Dumping core ...");
1358 #endif
1359 ::abort(); // dump core
1360 }
1361
1362 ::exit(1);
1363 }
1364
1365 // Die immediately, no exit hook, no abort hook, no cleanup.
1366 void os::die() {
1367 ::abort();
1368 }
1369
1370 // thread_id is kernel thread id (similar to Solaris LWP id)
1371 intx os::current_thread_id() { return os::Linux::gettid(); }
1372 int os::current_process_id() {
1373 return ::getpid();
1374 }
1375
1376 // DLL functions
1377
1378 const char* os::dll_file_extension() { return ".so"; }
1379
1380 // This must be hard coded because it's the system's temporary
1381 // directory not the java application's temp directory, ala java.io.tmpdir.
1382 const char* os::get_temp_directory() { return "/tmp"; }
1383
1384 static bool file_exists(const char* filename) {
1385 struct stat statbuf;
1386 if (filename == NULL || strlen(filename) == 0) {
1387 return false;
1388 }
1389 return os::stat(filename, &statbuf) == 0;
1390 }
1391
1392 // check if addr is inside libjvm.so
1393 bool os::address_is_in_vm(address addr) {
1394 static address libjvm_base_addr;
1395 Dl_info dlinfo;
1396
1397 if (libjvm_base_addr == NULL) {
1398 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1399 libjvm_base_addr = (address)dlinfo.dli_fbase;
1400 }
1401 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1402 }
1403
1404 if (dladdr((void *)addr, &dlinfo) != 0) {
1405 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1406 }
1407
1408 return false;
1409 }
1410
1411 bool os::dll_address_to_function_name(address addr, char *buf,
1412 int buflen, int *offset,
1413 bool demangle) {
1414 // buf is not optional, but offset is optional
1415 assert(buf != NULL, "sanity check");
1416
1417 Dl_info dlinfo;
1418
1419 if (dladdr((void*)addr, &dlinfo) != 0) {
1420 // see if we have a matching symbol
1421 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1422 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1423 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1424 }
1425 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1426 return true;
1427 }
1428 // no matching symbol so try for just file info
1429 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1430 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1431 buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1432 return true;
1433 }
1434 }
1435 }
1436
1437 buf[0] = '\0';
1438 if (offset != NULL) *offset = -1;
1439 return false;
1440 }
1441
1442 struct _address_to_library_name {
1443 address addr; // input : memory address
1444 size_t buflen; // size of fname
1445 char* fname; // output: library name
1446 address base; // library base addr
1447 };
1448
1449 static int address_to_library_name_callback(struct dl_phdr_info *info,
1450 size_t size, void *data) {
1451 int i;
1452 bool found = false;
1453 address libbase = NULL;
1454 struct _address_to_library_name * d = (struct _address_to_library_name *)data;
1455
1456 // iterate through all loadable segments
1457 for (i = 0; i < info->dlpi_phnum; i++) {
1458 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
1459 if (info->dlpi_phdr[i].p_type == PT_LOAD) {
1460 // base address of a library is the lowest address of its loaded
1461 // segments.
1462 if (libbase == NULL || libbase > segbase) {
1463 libbase = segbase;
1464 }
1465 // see if 'addr' is within current segment
1466 if (segbase <= d->addr &&
1467 d->addr < segbase + info->dlpi_phdr[i].p_memsz) {
1468 found = true;
1469 }
1470 }
1471 }
1472
1473 // dlpi_name is NULL or empty if the ELF file is executable, return 0
1474 // so dll_address_to_library_name() can fall through to use dladdr() which
1475 // can figure out executable name from argv[0].
1476 if (found && info->dlpi_name && info->dlpi_name[0]) {
1477 d->base = libbase;
1478 if (d->fname) {
1479 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name);
1480 }
1481 return 1;
1482 }
1483 return 0;
1484 }
1485
1486 bool os::dll_address_to_library_name(address addr, char* buf,
1487 int buflen, int* offset) {
1488 // buf is not optional, but offset is optional
1489 assert(buf != NULL, "sanity check");
1490
1491 Dl_info dlinfo;
1492 struct _address_to_library_name data;
1493
1494 // There is a bug in old glibc dladdr() implementation that it could resolve
1495 // to wrong library name if the .so file has a base address != NULL. Here
1496 // we iterate through the program headers of all loaded libraries to find
1497 // out which library 'addr' really belongs to. This workaround can be
1498 // removed once the minimum requirement for glibc is moved to 2.3.x.
1499 data.addr = addr;
1500 data.fname = buf;
1501 data.buflen = buflen;
1502 data.base = NULL;
1503 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data);
1504
1505 if (rslt) {
1506 // buf already contains library name
1507 if (offset) *offset = addr - data.base;
1508 return true;
1509 }
1510 if (dladdr((void*)addr, &dlinfo) != 0) {
1511 if (dlinfo.dli_fname != NULL) {
1512 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1513 }
1514 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1515 *offset = addr - (address)dlinfo.dli_fbase;
1516 }
1517 return true;
1518 }
1519
1520 buf[0] = '\0';
1521 if (offset) *offset = -1;
1522 return false;
1523 }
1524
1525 // Loads .dll/.so and
1526 // in case of error it checks if .dll/.so was built for the
1527 // same architecture as Hotspot is running on
1528
1529
1530 // Remember the stack's state. The Linux dynamic linker will change
1531 // the stack to 'executable' at most once, so we must safepoint only once.
1532 bool os::Linux::_stack_is_executable = false;
1533
1534 // VM operation that loads a library. This is necessary if stack protection
1535 // of the Java stacks can be lost during loading the library. If we
1536 // do not stop the Java threads, they can stack overflow before the stacks
1537 // are protected again.
1538 class VM_LinuxDllLoad: public VM_Operation {
1539 private:
1540 const char *_filename;
1541 char *_ebuf;
1542 int _ebuflen;
1543 void *_lib;
1544 public:
1545 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) :
1546 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {}
1547 VMOp_Type type() const { return VMOp_LinuxDllLoad; }
1548 void doit() {
1549 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen);
1550 os::Linux::_stack_is_executable = true;
1551 }
1552 void* loaded_library() { return _lib; }
1553 };
1554
1555 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1556 void * result = NULL;
1557 bool load_attempted = false;
1558
1559 // Check whether the library to load might change execution rights
1560 // of the stack. If they are changed, the protection of the stack
1561 // guard pages will be lost. We need a safepoint to fix this.
1562 //
1563 // See Linux man page execstack(8) for more info.
1564 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) {
1565 if (!ElfFile::specifies_noexecstack(filename)) {
1566 if (!is_init_completed()) {
1567 os::Linux::_stack_is_executable = true;
1568 // This is OK - No Java threads have been created yet, and hence no
1569 // stack guard pages to fix.
1570 //
1571 // Dynamic loader will make all stacks executable after
1572 // this function returns, and will not do that again.
1573 assert(Threads::number_of_threads() == 0, "no Java threads should exist yet.");
1574 } else {
1575 warning("You have loaded library %s which might have disabled stack guard. "
1576 "The VM will try to fix the stack guard now.\n"
1577 "It's highly recommended that you fix the library with "
1578 "'execstack -c <libfile>', or link it with '-z noexecstack'.",
1579 filename);
1580
1581 assert(Thread::current()->is_Java_thread(), "must be Java thread");
1582 JavaThread *jt = JavaThread::current();
1583 if (jt->thread_state() != _thread_in_native) {
1584 // This happens when a compiler thread tries to load a hsdis-<arch>.so file
1585 // that requires ExecStack. Cannot enter safe point. Let's give up.
1586 warning("Unable to fix stack guard. Giving up.");
1587 } else {
1588 if (!LoadExecStackDllInVMThread) {
1589 // This is for the case where the DLL has an static
1590 // constructor function that executes JNI code. We cannot
1591 // load such DLLs in the VMThread.
1592 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1593 }
1594
1595 ThreadInVMfromNative tiv(jt);
1596 debug_only(VMNativeEntryWrapper vew;)
1597
1598 VM_LinuxDllLoad op(filename, ebuf, ebuflen);
1599 VMThread::execute(&op);
1600 if (LoadExecStackDllInVMThread) {
1601 result = op.loaded_library();
1602 }
1603 load_attempted = true;
1604 }
1605 }
1606 }
1607 }
1608
1609 if (!load_attempted) {
1610 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1611 }
1612
1613 if (result != NULL) {
1614 // Successful loading
1615 return result;
1616 }
1617
1618 Elf32_Ehdr elf_head;
1619 int diag_msg_max_length=ebuflen-strlen(ebuf);
1620 char* diag_msg_buf=ebuf+strlen(ebuf);
1621
1622 if (diag_msg_max_length==0) {
1623 // No more space in ebuf for additional diagnostics message
1624 return NULL;
1625 }
1626
1627
1628 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1629
1630 if (file_descriptor < 0) {
1631 // Can't open library, report dlerror() message
1632 return NULL;
1633 }
1634
1635 bool failed_to_read_elf_head=
1636 (sizeof(elf_head)!=
1637 (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1638
1639 ::close(file_descriptor);
1640 if (failed_to_read_elf_head) {
1641 // file i/o error - report dlerror() msg
1642 return NULL;
1643 }
1644
1645 typedef struct {
1646 Elf32_Half code; // Actual value as defined in elf.h
1647 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1648 unsigned char elf_class; // 32 or 64 bit
1649 unsigned char endianess; // MSB or LSB
1650 char* name; // String representation
1651 } arch_t;
1652
1653 #ifndef EM_486
1654 #define EM_486 6 /* Intel 80486 */
1655 #endif
1656 #ifndef EM_AARCH64
1657 #define EM_AARCH64 183 /* ARM AARCH64 */
1658 #endif
1659
1660 static const arch_t arch_array[]={
1661 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1662 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1663 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1664 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1665 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1666 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1667 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1668 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1669 #if defined(VM_LITTLE_ENDIAN)
1670 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"},
1671 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"},
1672 #else
1673 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1674 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"},
1675 #endif
1676 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1677 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1678 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1679 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1680 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1681 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1682 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"},
1683 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"},
1684 };
1685
1686 #if (defined IA32)
1687 static Elf32_Half running_arch_code=EM_386;
1688 #elif (defined AMD64) || (defined X32)
1689 static Elf32_Half running_arch_code=EM_X86_64;
1690 #elif (defined IA64)
1691 static Elf32_Half running_arch_code=EM_IA_64;
1692 #elif (defined __sparc) && (defined _LP64)
1693 static Elf32_Half running_arch_code=EM_SPARCV9;
1694 #elif (defined __sparc) && (!defined _LP64)
1695 static Elf32_Half running_arch_code=EM_SPARC;
1696 #elif (defined __powerpc64__)
1697 static Elf32_Half running_arch_code=EM_PPC64;
1698 #elif (defined __powerpc__)
1699 static Elf32_Half running_arch_code=EM_PPC;
1700 #elif (defined AARCH64)
1701 static Elf32_Half running_arch_code=EM_AARCH64;
1702 #elif (defined ARM)
1703 static Elf32_Half running_arch_code=EM_ARM;
1704 #elif (defined S390)
1705 static Elf32_Half running_arch_code=EM_S390;
1706 #elif (defined ALPHA)
1707 static Elf32_Half running_arch_code=EM_ALPHA;
1708 #elif (defined MIPSEL)
1709 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1710 #elif (defined PARISC)
1711 static Elf32_Half running_arch_code=EM_PARISC;
1712 #elif (defined MIPS)
1713 static Elf32_Half running_arch_code=EM_MIPS;
1714 #elif (defined M68K)
1715 static Elf32_Half running_arch_code=EM_68K;
1716 #elif (defined SH)
1717 static Elf32_Half running_arch_code=EM_SH;
1718 #else
1719 #error Method os::dll_load requires that one of following is defined:\
1720 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc
1721 #endif
1722
1723 // Identify compatability class for VM's architecture and library's architecture
1724 // Obtain string descriptions for architectures
1725
1726 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1727 int running_arch_index=-1;
1728
1729 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1730 if (running_arch_code == arch_array[i].code) {
1731 running_arch_index = i;
1732 }
1733 if (lib_arch.code == arch_array[i].code) {
1734 lib_arch.compat_class = arch_array[i].compat_class;
1735 lib_arch.name = arch_array[i].name;
1736 }
1737 }
1738
1739 assert(running_arch_index != -1,
1740 "Didn't find running architecture code (running_arch_code) in arch_array");
1741 if (running_arch_index == -1) {
1742 // Even though running architecture detection failed
1743 // we may still continue with reporting dlerror() message
1744 return NULL;
1745 }
1746
1747 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1748 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1749 return NULL;
1750 }
1751
1752 #ifndef S390
1753 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1754 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1755 return NULL;
1756 }
1757 #endif // !S390
1758
1759 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1760 if (lib_arch.name!=NULL) {
1761 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1762 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1763 lib_arch.name, arch_array[running_arch_index].name);
1764 } else {
1765 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1766 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1767 lib_arch.code,
1768 arch_array[running_arch_index].name);
1769 }
1770 }
1771
1772 return NULL;
1773 }
1774
1775 void * os::Linux::dlopen_helper(const char *filename, char *ebuf,
1776 int ebuflen) {
1777 void * result = ::dlopen(filename, RTLD_LAZY);
1778 if (result == NULL) {
1779 ::strncpy(ebuf, ::dlerror(), ebuflen - 1);
1780 ebuf[ebuflen-1] = '\0';
1781 }
1782 return result;
1783 }
1784
1785 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf,
1786 int ebuflen) {
1787 void * result = NULL;
1788 if (LoadExecStackDllInVMThread) {
1789 result = dlopen_helper(filename, ebuf, ebuflen);
1790 }
1791
1792 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a
1793 // library that requires an executable stack, or which does not have this
1794 // stack attribute set, dlopen changes the stack attribute to executable. The
1795 // read protection of the guard pages gets lost.
1796 //
1797 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad
1798 // may have been queued at the same time.
1799
1800 if (!_stack_is_executable) {
1801 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
1802 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized
1803 jt->stack_guards_enabled()) { // No pending stack overflow exceptions
1804 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) {
1805 warning("Attempt to reguard stack yellow zone failed.");
1806 }
1807 }
1808 }
1809 }
1810
1811 return result;
1812 }
1813
1814 void* os::dll_lookup(void* handle, const char* name) {
1815 void* res = dlsym(handle, name);
1816 return res;
1817 }
1818
1819 void* os::get_default_process_handle() {
1820 return (void*)::dlopen(NULL, RTLD_LAZY);
1821 }
1822
1823 static bool _print_ascii_file(const char* filename, outputStream* st, const char* hdr = NULL) {
1824 int fd = ::open(filename, O_RDONLY);
1825 if (fd == -1) {
1826 return false;
1827 }
1828
1829 if (hdr != NULL) {
1830 st->print_cr("%s", hdr);
1831 }
1832
1833 char buf[33];
1834 int bytes;
1835 buf[32] = '\0';
1836 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) {
1837 st->print_raw(buf, bytes);
1838 }
1839
1840 ::close(fd);
1841
1842 return true;
1843 }
1844
1845 void os::print_dll_info(outputStream *st) {
1846 st->print_cr("Dynamic libraries:");
1847
1848 char fname[32];
1849 pid_t pid = os::Linux::gettid();
1850
1851 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid);
1852
1853 if (!_print_ascii_file(fname, st)) {
1854 st->print("Can not get library information for pid = %d\n", pid);
1855 }
1856 }
1857
1858 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1859 FILE *procmapsFile = NULL;
1860
1861 // Open the procfs maps file for the current process
1862 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) {
1863 // Allocate PATH_MAX for file name plus a reasonable size for other fields.
1864 char line[PATH_MAX + 100];
1865
1866 // Read line by line from 'file'
1867 while (fgets(line, sizeof(line), procmapsFile) != NULL) {
1868 u8 base, top, offset, inode;
1869 char permissions[5];
1870 char device[6];
1871 char name[PATH_MAX + 1];
1872
1873 // Parse fields from line
1874 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s",
1875 &base, &top, permissions, &offset, device, &inode, name);
1876
1877 // Filter by device id '00:00' so that we only get file system mapped files.
1878 if (strcmp(device, "00:00") != 0) {
1879
1880 // Call callback with the fields of interest
1881 if(callback(name, (address)base, (address)top, param)) {
1882 // Oops abort, callback aborted
1883 fclose(procmapsFile);
1884 return 1;
1885 }
1886 }
1887 }
1888 fclose(procmapsFile);
1889 }
1890 return 0;
1891 }
1892
1893 void os::print_os_info_brief(outputStream* st) {
1894 os::Linux::print_distro_info(st);
1895
1896 os::Posix::print_uname_info(st);
1897
1898 os::Linux::print_libversion_info(st);
1899
1900 }
1901
1902 void os::print_os_info(outputStream* st) {
1903 st->print("OS:");
1904
1905 os::Linux::print_distro_info(st);
1906
1907 os::Posix::print_uname_info(st);
1908
1909 // Print warning if unsafe chroot environment detected
1910 if (unsafe_chroot_detected) {
1911 st->print("WARNING!! ");
1912 st->print_cr("%s", unstable_chroot_error);
1913 }
1914
1915 os::Linux::print_libversion_info(st);
1916
1917 os::Posix::print_rlimit_info(st);
1918
1919 os::Posix::print_load_average(st);
1920
1921 os::Linux::print_full_memory_info(st);
1922
1923 os::Linux::print_proc_sys_info(st);
1924
1925 os::Linux::print_ld_preload_file(st);
1926
1927 os::Linux::print_container_info(st);
1928 }
1929
1930 // Try to identify popular distros.
1931 // Most Linux distributions have a /etc/XXX-release file, which contains
1932 // the OS version string. Newer Linux distributions have a /etc/lsb-release
1933 // file that also contains the OS version string. Some have more than one
1934 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and
1935 // /etc/redhat-release.), so the order is important.
1936 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have
1937 // their own specific XXX-release file as well as a redhat-release file.
1938 // Because of this the XXX-release file needs to be searched for before the
1939 // redhat-release file.
1940 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the
1941 // search for redhat-release / SuSE-release needs to be before lsb-release.
1942 // Since the lsb-release file is the new standard it needs to be searched
1943 // before the older style release files.
1944 // Searching system-release (Red Hat) and os-release (other Linuxes) are a
1945 // next to last resort. The os-release file is a new standard that contains
1946 // distribution information and the system-release file seems to be an old
1947 // standard that has been replaced by the lsb-release and os-release files.
1948 // Searching for the debian_version file is the last resort. It contains
1949 // an informative string like "6.0.6" or "wheezy/sid". Because of this
1950 // "Debian " is printed before the contents of the debian_version file.
1951
1952 const char* distro_files[] = {
1953 "/etc/oracle-release",
1954 "/etc/mandriva-release",
1955 "/etc/mandrake-release",
1956 "/etc/sun-release",
1957 "/etc/redhat-release",
1958 "/etc/SuSE-release",
1959 "/etc/lsb-release",
1960 "/etc/turbolinux-release",
1961 "/etc/gentoo-release",
1962 "/etc/ltib-release",
1963 "/etc/angstrom-version",
1964 "/etc/system-release",
1965 "/etc/os-release",
1966 NULL };
1967
1968 void os::Linux::print_distro_info(outputStream* st) {
1969 for (int i = 0;; i++) {
1970 const char* file = distro_files[i];
1971 if (file == NULL) {
1972 break; // done
1973 }
1974 // If file prints, we found it.
1975 if (_print_ascii_file(file, st)) {
1976 return;
1977 }
1978 }
1979
1980 if (file_exists("/etc/debian_version")) {
1981 st->print("Debian ");
1982 _print_ascii_file("/etc/debian_version", st);
1983 } else {
1984 st->print("Linux");
1985 }
1986 st->cr();
1987 }
1988
1989 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) {
1990 char buf[256];
1991 while (fgets(buf, sizeof(buf), fp)) {
1992 // Edit out extra stuff in expected format
1993 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) {
1994 char* ptr = strstr(buf, "\""); // the name is in quotes
1995 if (ptr != NULL) {
1996 ptr++; // go beyond first quote
1997 char* nl = strchr(ptr, '\"');
1998 if (nl != NULL) *nl = '\0';
1999 strncpy(distro, ptr, length);
2000 } else {
2001 ptr = strstr(buf, "=");
2002 ptr++; // go beyond equals then
2003 char* nl = strchr(ptr, '\n');
2004 if (nl != NULL) *nl = '\0';
2005 strncpy(distro, ptr, length);
2006 }
2007 return;
2008 } else if (get_first_line) {
2009 char* nl = strchr(buf, '\n');
2010 if (nl != NULL) *nl = '\0';
2011 strncpy(distro, buf, length);
2012 return;
2013 }
2014 }
2015 // print last line and close
2016 char* nl = strchr(buf, '\n');
2017 if (nl != NULL) *nl = '\0';
2018 strncpy(distro, buf, length);
2019 }
2020
2021 static void parse_os_info(char* distro, size_t length, const char* file) {
2022 FILE* fp = fopen(file, "r");
2023 if (fp != NULL) {
2024 // if suse format, print out first line
2025 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0);
2026 parse_os_info_helper(fp, distro, length, get_first_line);
2027 fclose(fp);
2028 }
2029 }
2030
2031 void os::get_summary_os_info(char* buf, size_t buflen) {
2032 for (int i = 0;; i++) {
2033 const char* file = distro_files[i];
2034 if (file == NULL) {
2035 break; // ran out of distro_files
2036 }
2037 if (file_exists(file)) {
2038 parse_os_info(buf, buflen, file);
2039 return;
2040 }
2041 }
2042 // special case for debian
2043 if (file_exists("/etc/debian_version")) {
2044 strncpy(buf, "Debian ", buflen);
2045 if (buflen > 7) {
2046 parse_os_info(&buf[7], buflen-7, "/etc/debian_version");
2047 }
2048 } else {
2049 strncpy(buf, "Linux", buflen);
2050 }
2051 }
2052
2053 void os::Linux::print_libversion_info(outputStream* st) {
2054 // libc, pthread
2055 st->print("libc:");
2056 st->print("%s ", os::Linux::glibc_version());
2057 st->print("%s ", os::Linux::libpthread_version());
2058 st->cr();
2059 }
2060
2061 void os::Linux::print_proc_sys_info(outputStream* st) {
2062 st->cr();
2063 st->print_cr("/proc/sys/kernel/threads-max (system-wide limit on the number of threads):");
2064 _print_ascii_file("/proc/sys/kernel/threads-max", st);
2065 st->cr();
2066 st->cr();
2067
2068 st->print_cr("/proc/sys/vm/max_map_count (maximum number of memory map areas a process may have):");
2069 _print_ascii_file("/proc/sys/vm/max_map_count", st);
2070 st->cr();
2071 st->cr();
2072
2073 st->print_cr("/proc/sys/kernel/pid_max (system-wide limit on number of process identifiers):");
2074 _print_ascii_file("/proc/sys/kernel/pid_max", st);
2075 st->cr();
2076 st->cr();
2077 }
2078
2079 void os::Linux::print_full_memory_info(outputStream* st) {
2080 st->print("\n/proc/meminfo:\n");
2081 _print_ascii_file("/proc/meminfo", st);
2082 st->cr();
2083 }
2084
2085 void os::Linux::print_ld_preload_file(outputStream* st) {
2086 _print_ascii_file("/etc/ld.so.preload", st, "\n/etc/ld.so.preload:");
2087 st->cr();
2088 }
2089
2090 void os::Linux::print_container_info(outputStream* st) {
2091 if (!OSContainer::is_containerized()) {
2092 return;
2093 }
2094
2095 st->print("container (cgroup) information:\n");
2096
2097 const char *p_ct = OSContainer::container_type();
2098 st->print("container_type: %s\n", p_ct != NULL ? p_ct : "failed");
2099
2100 char *p = OSContainer::cpu_cpuset_cpus();
2101 st->print("cpu_cpuset_cpus: %s\n", p != NULL ? p : "failed");
2102 free(p);
2103
2104 p = OSContainer::cpu_cpuset_memory_nodes();
2105 st->print("cpu_memory_nodes: %s\n", p != NULL ? p : "failed");
2106 free(p);
2107
2108 int i = OSContainer::active_processor_count();
2109 if (i > 0) {
2110 st->print("active_processor_count: %d\n", i);
2111 } else {
2112 st->print("active_processor_count: failed\n");
2113 }
2114
2115 i = OSContainer::cpu_quota();
2116 st->print("cpu_quota: %d\n", i);
2117
2118 i = OSContainer::cpu_period();
2119 st->print("cpu_period: %d\n", i);
2120
2121 i = OSContainer::cpu_shares();
2122 st->print("cpu_shares: %d\n", i);
2123
2124 jlong j = OSContainer::memory_limit_in_bytes();
2125 st->print("memory_limit_in_bytes: " JLONG_FORMAT "\n", j);
2126
2127 j = OSContainer::memory_and_swap_limit_in_bytes();
2128 st->print("memory_and_swap_limit_in_bytes: " JLONG_FORMAT "\n", j);
2129
2130 j = OSContainer::memory_soft_limit_in_bytes();
2131 st->print("memory_soft_limit_in_bytes: " JLONG_FORMAT "\n", j);
2132
2133 j = OSContainer::OSContainer::memory_usage_in_bytes();
2134 st->print("memory_usage_in_bytes: " JLONG_FORMAT "\n", j);
2135
2136 j = OSContainer::OSContainer::memory_max_usage_in_bytes();
2137 st->print("memory_max_usage_in_bytes: " JLONG_FORMAT "\n", j);
2138 st->cr();
2139 }
2140
2141 void os::print_memory_info(outputStream* st) {
2142
2143 st->print("Memory:");
2144 st->print(" %dk page", os::vm_page_size()>>10);
2145
2146 // values in struct sysinfo are "unsigned long"
2147 struct sysinfo si;
2148 sysinfo(&si);
2149
2150 st->print(", physical " UINT64_FORMAT "k",
2151 os::physical_memory() >> 10);
2152 st->print("(" UINT64_FORMAT "k free)",
2153 os::available_memory() >> 10);
2154 st->print(", swap " UINT64_FORMAT "k",
2155 ((jlong)si.totalswap * si.mem_unit) >> 10);
2156 st->print("(" UINT64_FORMAT "k free)",
2157 ((jlong)si.freeswap * si.mem_unit) >> 10);
2158 st->cr();
2159 }
2160
2161 // Print the first "model name" line and the first "flags" line
2162 // that we find and nothing more. We assume "model name" comes
2163 // before "flags" so if we find a second "model name", then the
2164 // "flags" field is considered missing.
2165 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) {
2166 #if defined(IA32) || defined(AMD64)
2167 // Other platforms have less repetitive cpuinfo files
2168 FILE *fp = fopen("/proc/cpuinfo", "r");
2169 if (fp) {
2170 while (!feof(fp)) {
2171 if (fgets(buf, buflen, fp)) {
2172 // Assume model name comes before flags
2173 bool model_name_printed = false;
2174 if (strstr(buf, "model name") != NULL) {
2175 if (!model_name_printed) {
2176 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n");
2177 st->print_raw(buf);
2178 model_name_printed = true;
2179 } else {
2180 // model name printed but not flags? Odd, just return
2181 fclose(fp);
2182 return true;
2183 }
2184 }
2185 // print the flags line too
2186 if (strstr(buf, "flags") != NULL) {
2187 st->print_raw(buf);
2188 fclose(fp);
2189 return true;
2190 }
2191 }
2192 }
2193 fclose(fp);
2194 }
2195 #endif // x86 platforms
2196 return false;
2197 }
2198
2199 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
2200 // Only print the model name if the platform provides this as a summary
2201 if (!print_model_name_and_flags(st, buf, buflen)) {
2202 st->print("\n/proc/cpuinfo:\n");
2203 if (!_print_ascii_file("/proc/cpuinfo", st)) {
2204 st->print_cr(" <Not Available>");
2205 }
2206 }
2207 }
2208
2209 #if defined(AMD64) || defined(IA32) || defined(X32)
2210 const char* search_string = "model name";
2211 #elif defined(M68K)
2212 const char* search_string = "CPU";
2213 #elif defined(PPC64)
2214 const char* search_string = "cpu";
2215 #elif defined(S390)
2216 const char* search_string = "processor";
2217 #elif defined(SPARC)
2218 const char* search_string = "cpu";
2219 #else
2220 const char* search_string = "Processor";
2221 #endif
2222
2223 // Parses the cpuinfo file for string representing the model name.
2224 void os::get_summary_cpu_info(char* cpuinfo, size_t length) {
2225 FILE* fp = fopen("/proc/cpuinfo", "r");
2226 if (fp != NULL) {
2227 while (!feof(fp)) {
2228 char buf[256];
2229 if (fgets(buf, sizeof(buf), fp)) {
2230 char* start = strstr(buf, search_string);
2231 if (start != NULL) {
2232 char *ptr = start + strlen(search_string);
2233 char *end = buf + strlen(buf);
2234 while (ptr != end) {
2235 // skip whitespace and colon for the rest of the name.
2236 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') {
2237 break;
2238 }
2239 ptr++;
2240 }
2241 if (ptr != end) {
2242 // reasonable string, get rid of newline and keep the rest
2243 char* nl = strchr(buf, '\n');
2244 if (nl != NULL) *nl = '\0';
2245 strncpy(cpuinfo, ptr, length);
2246 fclose(fp);
2247 return;
2248 }
2249 }
2250 }
2251 }
2252 fclose(fp);
2253 }
2254 // cpuinfo not found or parsing failed, just print generic string. The entire
2255 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86)
2256 #if defined(AARCH64)
2257 strncpy(cpuinfo, "AArch64", length);
2258 #elif defined(AMD64)
2259 strncpy(cpuinfo, "x86_64", length);
2260 #elif defined(ARM) // Order wrt. AARCH64 is relevant!
2261 strncpy(cpuinfo, "ARM", length);
2262 #elif defined(IA32)
2263 strncpy(cpuinfo, "x86_32", length);
2264 #elif defined(IA64)
2265 strncpy(cpuinfo, "IA64", length);
2266 #elif defined(PPC)
2267 strncpy(cpuinfo, "PPC64", length);
2268 #elif defined(S390)
2269 strncpy(cpuinfo, "S390", length);
2270 #elif defined(SPARC)
2271 strncpy(cpuinfo, "sparcv9", length);
2272 #elif defined(ZERO_LIBARCH)
2273 strncpy(cpuinfo, ZERO_LIBARCH, length);
2274 #else
2275 strncpy(cpuinfo, "unknown", length);
2276 #endif
2277 }
2278
2279 static void print_signal_handler(outputStream* st, int sig,
2280 char* buf, size_t buflen);
2281
2282 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
2283 st->print_cr("Signal Handlers:");
2284 print_signal_handler(st, SIGSEGV, buf, buflen);
2285 print_signal_handler(st, SIGBUS , buf, buflen);
2286 print_signal_handler(st, SIGFPE , buf, buflen);
2287 print_signal_handler(st, SIGPIPE, buf, buflen);
2288 print_signal_handler(st, SIGXFSZ, buf, buflen);
2289 print_signal_handler(st, SIGILL , buf, buflen);
2290 print_signal_handler(st, SR_signum, buf, buflen);
2291 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
2292 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
2293 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
2294 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
2295 #if defined(PPC64)
2296 print_signal_handler(st, SIGTRAP, buf, buflen);
2297 #endif
2298 }
2299
2300 static char saved_jvm_path[MAXPATHLEN] = {0};
2301
2302 // Find the full path to the current module, libjvm.so
2303 void os::jvm_path(char *buf, jint buflen) {
2304 // Error checking.
2305 if (buflen < MAXPATHLEN) {
2306 assert(false, "must use a large-enough buffer");
2307 buf[0] = '\0';
2308 return;
2309 }
2310 // Lazy resolve the path to current module.
2311 if (saved_jvm_path[0] != 0) {
2312 strcpy(buf, saved_jvm_path);
2313 return;
2314 }
2315
2316 char dli_fname[MAXPATHLEN];
2317 bool ret = dll_address_to_library_name(
2318 CAST_FROM_FN_PTR(address, os::jvm_path),
2319 dli_fname, sizeof(dli_fname), NULL);
2320 assert(ret, "cannot locate libjvm");
2321 char *rp = NULL;
2322 if (ret && dli_fname[0] != '\0') {
2323 rp = os::Posix::realpath(dli_fname, buf, buflen);
2324 }
2325 if (rp == NULL) {
2326 return;
2327 }
2328
2329 if (Arguments::sun_java_launcher_is_altjvm()) {
2330 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
2331 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
2332 // If "/jre/lib/" appears at the right place in the string, then
2333 // assume we are installed in a JDK and we're done. Otherwise, check
2334 // for a JAVA_HOME environment variable and fix up the path so it
2335 // looks like libjvm.so is installed there (append a fake suffix
2336 // hotspot/libjvm.so).
2337 const char *p = buf + strlen(buf) - 1;
2338 for (int count = 0; p > buf && count < 5; ++count) {
2339 for (--p; p > buf && *p != '/'; --p)
2340 /* empty */ ;
2341 }
2342
2343 if (strncmp(p, "/jre/lib/", 9) != 0) {
2344 // Look for JAVA_HOME in the environment.
2345 char* java_home_var = ::getenv("JAVA_HOME");
2346 if (java_home_var != NULL && java_home_var[0] != 0) {
2347 char* jrelib_p;
2348 int len;
2349
2350 // Check the current module name "libjvm.so".
2351 p = strrchr(buf, '/');
2352 if (p == NULL) {
2353 return;
2354 }
2355 assert(strstr(p, "/libjvm") == p, "invalid library name");
2356
2357 rp = os::Posix::realpath(java_home_var, buf, buflen);
2358 if (rp == NULL) {
2359 return;
2360 }
2361
2362 // determine if this is a legacy image or modules image
2363 // modules image doesn't have "jre" subdirectory
2364 len = strlen(buf);
2365 assert(len < buflen, "Ran out of buffer room");
2366 jrelib_p = buf + len;
2367 snprintf(jrelib_p, buflen-len, "/jre/lib");
2368 if (0 != access(buf, F_OK)) {
2369 snprintf(jrelib_p, buflen-len, "/lib");
2370 }
2371
2372 if (0 == access(buf, F_OK)) {
2373 // Use current module name "libjvm.so"
2374 len = strlen(buf);
2375 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
2376 } else {
2377 // Go back to path of .so
2378 rp = os::Posix::realpath(dli_fname, buf, buflen);
2379 if (rp == NULL) {
2380 return;
2381 }
2382 }
2383 }
2384 }
2385 }
2386
2387 strncpy(saved_jvm_path, buf, MAXPATHLEN);
2388 saved_jvm_path[MAXPATHLEN - 1] = '\0';
2389 }
2390
2391 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
2392 // no prefix required, not even "_"
2393 }
2394
2395 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
2396 // no suffix required
2397 }
2398
2399 ////////////////////////////////////////////////////////////////////////////////
2400 // sun.misc.Signal support
2401
2402 static volatile jint sigint_count = 0;
2403
2404 static void UserHandler(int sig, void *siginfo, void *context) {
2405 // 4511530 - sem_post is serialized and handled by the manager thread. When
2406 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
2407 // don't want to flood the manager thread with sem_post requests.
2408 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
2409 return;
2410 }
2411
2412 // Ctrl-C is pressed during error reporting, likely because the error
2413 // handler fails to abort. Let VM die immediately.
2414 if (sig == SIGINT && VMError::is_error_reported()) {
2415 os::die();
2416 }
2417
2418 os::signal_notify(sig);
2419 }
2420
2421 void* os::user_handler() {
2422 return CAST_FROM_FN_PTR(void*, UserHandler);
2423 }
2424
2425 static struct timespec create_semaphore_timespec(unsigned int sec, int nsec) {
2426 struct timespec ts;
2427 // Semaphore's are always associated with CLOCK_REALTIME
2428 os::Posix::clock_gettime(CLOCK_REALTIME, &ts);
2429 // see os_posix.cpp for discussion on overflow checking
2430 if (sec >= MAX_SECS) {
2431 ts.tv_sec += MAX_SECS;
2432 ts.tv_nsec = 0;
2433 } else {
2434 ts.tv_sec += sec;
2435 ts.tv_nsec += nsec;
2436 if (ts.tv_nsec >= NANOSECS_PER_SEC) {
2437 ts.tv_nsec -= NANOSECS_PER_SEC;
2438 ++ts.tv_sec; // note: this must be <= max_secs
2439 }
2440 }
2441
2442 return ts;
2443 }
2444
2445 extern "C" {
2446 typedef void (*sa_handler_t)(int);
2447 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
2448 }
2449
2450 void* os::signal(int signal_number, void* handler) {
2451 struct sigaction sigAct, oldSigAct;
2452
2453 sigfillset(&(sigAct.sa_mask));
2454 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
2455 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
2456
2457 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
2458 // -1 means registration failed
2459 return (void *)-1;
2460 }
2461
2462 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
2463 }
2464
2465 void os::signal_raise(int signal_number) {
2466 ::raise(signal_number);
2467 }
2468
2469 // The following code is moved from os.cpp for making this
2470 // code platform specific, which it is by its very nature.
2471
2472 // Will be modified when max signal is changed to be dynamic
2473 int os::sigexitnum_pd() {
2474 return NSIG;
2475 }
2476
2477 // a counter for each possible signal value
2478 static volatile jint pending_signals[NSIG+1] = { 0 };
2479
2480 // Linux(POSIX) specific hand shaking semaphore.
2481 static Semaphore* sig_sem = NULL;
2482 static PosixSemaphore sr_semaphore;
2483
2484 static void jdk_misc_signal_init() {
2485 // Initialize signal structures
2486 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2487
2488 // Initialize signal semaphore
2489 sig_sem = new Semaphore();
2490 }
2491
2492 void os::signal_notify(int sig) {
2493 if (sig_sem != NULL) {
2494 Atomic::inc(&pending_signals[sig]);
2495 sig_sem->signal();
2496 } else {
2497 // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
2498 // initialization isn't called.
2499 assert(ReduceSignalUsage, "signal semaphore should be created");
2500 }
2501 }
2502
2503 static int check_pending_signals() {
2504 Atomic::store(0, &sigint_count);
2505 for (;;) {
2506 for (int i = 0; i < NSIG + 1; i++) {
2507 jint n = pending_signals[i];
2508 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2509 return i;
2510 }
2511 }
2512 JavaThread *thread = JavaThread::current();
2513 ThreadBlockInVM tbivm(thread);
2514
2515 bool threadIsSuspended;
2516 do {
2517 thread->set_suspend_equivalent();
2518 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2519 sig_sem->wait();
2520
2521 // were we externally suspended while we were waiting?
2522 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2523 if (threadIsSuspended) {
2524 // The semaphore has been incremented, but while we were waiting
2525 // another thread suspended us. We don't want to continue running
2526 // while suspended because that would surprise the thread that
2527 // suspended us.
2528 sig_sem->signal();
2529
2530 thread->java_suspend_self();
2531 }
2532 } while (threadIsSuspended);
2533 }
2534 }
2535
2536 int os::signal_wait() {
2537 return check_pending_signals();
2538 }
2539
2540 ////////////////////////////////////////////////////////////////////////////////
2541 // Virtual Memory
2542
2543 int os::vm_page_size() {
2544 // Seems redundant as all get out
2545 assert(os::Linux::page_size() != -1, "must call os::init");
2546 return os::Linux::page_size();
2547 }
2548
2549 // Solaris allocates memory by pages.
2550 int os::vm_allocation_granularity() {
2551 assert(os::Linux::page_size() != -1, "must call os::init");
2552 return os::Linux::page_size();
2553 }
2554
2555 // Rationale behind this function:
2556 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2557 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2558 // samples for JITted code. Here we create private executable mapping over the code cache
2559 // and then we can use standard (well, almost, as mapping can change) way to provide
2560 // info for the reporting script by storing timestamp and location of symbol
2561 void linux_wrap_code(char* base, size_t size) {
2562 static volatile jint cnt = 0;
2563
2564 if (!UseOprofile) {
2565 return;
2566 }
2567
2568 char buf[PATH_MAX+1];
2569 int num = Atomic::add(1, &cnt);
2570
2571 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d",
2572 os::get_temp_directory(), os::current_process_id(), num);
2573 unlink(buf);
2574
2575 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2576
2577 if (fd != -1) {
2578 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2579 if (rv != (off_t)-1) {
2580 if (::write(fd, "", 1) == 1) {
2581 mmap(base, size,
2582 PROT_READ|PROT_WRITE|PROT_EXEC,
2583 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2584 }
2585 }
2586 ::close(fd);
2587 unlink(buf);
2588 }
2589 }
2590
2591 static bool recoverable_mmap_error(int err) {
2592 // See if the error is one we can let the caller handle. This
2593 // list of errno values comes from JBS-6843484. I can't find a
2594 // Linux man page that documents this specific set of errno
2595 // values so while this list currently matches Solaris, it may
2596 // change as we gain experience with this failure mode.
2597 switch (err) {
2598 case EBADF:
2599 case EINVAL:
2600 case ENOTSUP:
2601 // let the caller deal with these errors
2602 return true;
2603
2604 default:
2605 // Any remaining errors on this OS can cause our reserved mapping
2606 // to be lost. That can cause confusion where different data
2607 // structures think they have the same memory mapped. The worst
2608 // scenario is if both the VM and a library think they have the
2609 // same memory mapped.
2610 return false;
2611 }
2612 }
2613
2614 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2615 int err) {
2616 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2617 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
2618 os::strerror(err), err);
2619 }
2620
2621 static void warn_fail_commit_memory(char* addr, size_t size,
2622 size_t alignment_hint, bool exec,
2623 int err) {
2624 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2625 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size,
2626 alignment_hint, exec, os::strerror(err), err);
2627 }
2628
2629 // NOTE: Linux kernel does not really reserve the pages for us.
2630 // All it does is to check if there are enough free pages
2631 // left at the time of mmap(). This could be a potential
2632 // problem.
2633 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) {
2634 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2635 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2636 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2637 if (res != (uintptr_t) MAP_FAILED) {
2638 if (UseNUMAInterleaving) {
2639 numa_make_global(addr, size);
2640 }
2641 return 0;
2642 }
2643
2644 int err = errno; // save errno from mmap() call above
2645
2646 if (!recoverable_mmap_error(err)) {
2647 warn_fail_commit_memory(addr, size, exec, err);
2648 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory.");
2649 }
2650
2651 return err;
2652 }
2653
2654 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2655 return os::Linux::commit_memory_impl(addr, size, exec) == 0;
2656 }
2657
2658 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2659 const char* mesg) {
2660 assert(mesg != NULL, "mesg must be specified");
2661 int err = os::Linux::commit_memory_impl(addr, size, exec);
2662 if (err != 0) {
2663 // the caller wants all commit errors to exit with the specified mesg:
2664 warn_fail_commit_memory(addr, size, exec, err);
2665 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2666 }
2667 }
2668
2669 // Define MAP_HUGETLB here so we can build HotSpot on old systems.
2670 #ifndef MAP_HUGETLB
2671 #define MAP_HUGETLB 0x40000
2672 #endif
2673
2674 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems.
2675 #ifndef MADV_HUGEPAGE
2676 #define MADV_HUGEPAGE 14
2677 #endif
2678
2679 int os::Linux::commit_memory_impl(char* addr, size_t size,
2680 size_t alignment_hint, bool exec) {
2681 int err = os::Linux::commit_memory_impl(addr, size, exec);
2682 if (err == 0) {
2683 realign_memory(addr, size, alignment_hint);
2684 }
2685 return err;
2686 }
2687
2688 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2689 bool exec) {
2690 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0;
2691 }
2692
2693 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2694 size_t alignment_hint, bool exec,
2695 const char* mesg) {
2696 assert(mesg != NULL, "mesg must be specified");
2697 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec);
2698 if (err != 0) {
2699 // the caller wants all commit errors to exit with the specified mesg:
2700 warn_fail_commit_memory(addr, size, alignment_hint, exec, err);
2701 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2702 }
2703 }
2704
2705 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2706 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) {
2707 // We don't check the return value: madvise(MADV_HUGEPAGE) may not
2708 // be supported or the memory may already be backed by huge pages.
2709 ::madvise(addr, bytes, MADV_HUGEPAGE);
2710 }
2711 }
2712
2713 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2714 // This method works by doing an mmap over an existing mmaping and effectively discarding
2715 // the existing pages. However it won't work for SHM-based large pages that cannot be
2716 // uncommitted at all. We don't do anything in this case to avoid creating a segment with
2717 // small pages on top of the SHM segment. This method always works for small pages, so we
2718 // allow that in any case.
2719 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) {
2720 commit_memory(addr, bytes, alignment_hint, !ExecMem);
2721 }
2722 }
2723
2724 void os::numa_make_global(char *addr, size_t bytes) {
2725 Linux::numa_interleave_memory(addr, bytes);
2726 }
2727
2728 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the
2729 // bind policy to MPOL_PREFERRED for the current thread.
2730 #define USE_MPOL_PREFERRED 0
2731
2732 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2733 // To make NUMA and large pages more robust when both enabled, we need to ease
2734 // the requirements on where the memory should be allocated. MPOL_BIND is the
2735 // default policy and it will force memory to be allocated on the specified
2736 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on
2737 // the specified node, but will not force it. Using this policy will prevent
2738 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no
2739 // free large pages.
2740 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED);
2741 Linux::numa_tonode_memory(addr, bytes, lgrp_hint);
2742 }
2743
2744 bool os::numa_topology_changed() { return false; }
2745
2746 size_t os::numa_get_groups_num() {
2747 // Return just the number of nodes in which it's possible to allocate memory
2748 // (in numa terminology, configured nodes).
2749 return Linux::numa_num_configured_nodes();
2750 }
2751
2752 int os::numa_get_group_id() {
2753 int cpu_id = Linux::sched_getcpu();
2754 if (cpu_id != -1) {
2755 int lgrp_id = Linux::get_node_by_cpu(cpu_id);
2756 if (lgrp_id != -1) {
2757 return lgrp_id;
2758 }
2759 }
2760 return 0;
2761 }
2762
2763 int os::Linux::get_existing_num_nodes() {
2764 int node;
2765 int highest_node_number = Linux::numa_max_node();
2766 int num_nodes = 0;
2767
2768 // Get the total number of nodes in the system including nodes without memory.
2769 for (node = 0; node <= highest_node_number; node++) {
2770 if (isnode_in_existing_nodes(node)) {
2771 num_nodes++;
2772 }
2773 }
2774 return num_nodes;
2775 }
2776
2777 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2778 int highest_node_number = Linux::numa_max_node();
2779 size_t i = 0;
2780
2781 // Map all node ids in which it is possible to allocate memory. Also nodes are
2782 // not always consecutively available, i.e. available from 0 to the highest
2783 // node number. If the nodes have been bound explicitly using numactl membind,
2784 // then allocate memory from those nodes only.
2785 for (int node = 0; node <= highest_node_number; node++) {
2786 if (Linux::isnode_in_bound_nodes((unsigned int)node)) {
2787 ids[i++] = node;
2788 }
2789 }
2790 return i;
2791 }
2792
2793 bool os::get_page_info(char *start, page_info* info) {
2794 return false;
2795 }
2796
2797 char *os::scan_pages(char *start, char* end, page_info* page_expected,
2798 page_info* page_found) {
2799 return end;
2800 }
2801
2802
2803 int os::Linux::sched_getcpu_syscall(void) {
2804 unsigned int cpu = 0;
2805 int retval = -1;
2806
2807 #if defined(IA32)
2808 #ifndef SYS_getcpu
2809 #define SYS_getcpu 318
2810 #endif
2811 retval = syscall(SYS_getcpu, &cpu, NULL, NULL);
2812 #elif defined(AMD64)
2813 // Unfortunately we have to bring all these macros here from vsyscall.h
2814 // to be able to compile on old linuxes.
2815 #define __NR_vgetcpu 2
2816 #define VSYSCALL_START (-10UL << 20)
2817 #define VSYSCALL_SIZE 1024
2818 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
2819 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache);
2820 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu);
2821 retval = vgetcpu(&cpu, NULL, NULL);
2822 #endif
2823
2824 return (retval == -1) ? retval : cpu;
2825 }
2826
2827 void os::Linux::sched_getcpu_init() {
2828 // sched_getcpu() should be in libc.
2829 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
2830 dlsym(RTLD_DEFAULT, "sched_getcpu")));
2831
2832 // If it's not, try a direct syscall.
2833 if (sched_getcpu() == -1) {
2834 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
2835 (void*)&sched_getcpu_syscall));
2836 }
2837
2838 if (sched_getcpu() == -1) {
2839 vm_exit_during_initialization("getcpu(2) system call not supported by kernel");
2840 }
2841 }
2842
2843 // Something to do with the numa-aware allocator needs these symbols
2844 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { }
2845 extern "C" JNIEXPORT void numa_error(char *where) { }
2846
2847 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails
2848 // load symbol from base version instead.
2849 void* os::Linux::libnuma_dlsym(void* handle, const char *name) {
2850 void *f = dlvsym(handle, name, "libnuma_1.1");
2851 if (f == NULL) {
2852 f = dlsym(handle, name);
2853 }
2854 return f;
2855 }
2856
2857 // Handle request to load libnuma symbol version 1.2 (API v2) only.
2858 // Return NULL if the symbol is not defined in this particular version.
2859 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) {
2860 return dlvsym(handle, name, "libnuma_1.2");
2861 }
2862
2863 bool os::Linux::libnuma_init() {
2864 if (sched_getcpu() != -1) { // Requires sched_getcpu() support
2865 void *handle = dlopen("libnuma.so.1", RTLD_LAZY);
2866 if (handle != NULL) {
2867 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t,
2868 libnuma_dlsym(handle, "numa_node_to_cpus")));
2869 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t,
2870 libnuma_dlsym(handle, "numa_max_node")));
2871 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t,
2872 libnuma_dlsym(handle, "numa_num_configured_nodes")));
2873 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t,
2874 libnuma_dlsym(handle, "numa_available")));
2875 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t,
2876 libnuma_dlsym(handle, "numa_tonode_memory")));
2877 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t,
2878 libnuma_dlsym(handle, "numa_interleave_memory")));
2879 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t,
2880 libnuma_v2_dlsym(handle, "numa_interleave_memory")));
2881 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t,
2882 libnuma_dlsym(handle, "numa_set_bind_policy")));
2883 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t,
2884 libnuma_dlsym(handle, "numa_bitmask_isbitset")));
2885 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t,
2886 libnuma_dlsym(handle, "numa_distance")));
2887 set_numa_get_membind(CAST_TO_FN_PTR(numa_get_membind_func_t,
2888 libnuma_v2_dlsym(handle, "numa_get_membind")));
2889
2890 if (numa_available() != -1) {
2891 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes"));
2892 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr"));
2893 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr"));
2894 // Create an index -> node mapping, since nodes are not always consecutive
2895 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
2896 rebuild_nindex_to_node_map();
2897 // Create a cpu -> node mapping
2898 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
2899 rebuild_cpu_to_node_map();
2900 return true;
2901 }
2902 }
2903 }
2904 return false;
2905 }
2906
2907 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
2908 // Creating guard page is very expensive. Java thread has HotSpot
2909 // guard pages, only enable glibc guard page for non-Java threads.
2910 // (Remember: compiler thread is a Java thread, too!)
2911 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size());
2912 }
2913
2914 void os::Linux::rebuild_nindex_to_node_map() {
2915 int highest_node_number = Linux::numa_max_node();
2916
2917 nindex_to_node()->clear();
2918 for (int node = 0; node <= highest_node_number; node++) {
2919 if (Linux::isnode_in_existing_nodes(node)) {
2920 nindex_to_node()->append(node);
2921 }
2922 }
2923 }
2924
2925 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id.
2926 // The table is later used in get_node_by_cpu().
2927 void os::Linux::rebuild_cpu_to_node_map() {
2928 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure
2929 // in libnuma (possible values are starting from 16,
2930 // and continuing up with every other power of 2, but less
2931 // than the maximum number of CPUs supported by kernel), and
2932 // is a subject to change (in libnuma version 2 the requirements
2933 // are more reasonable) we'll just hardcode the number they use
2934 // in the library.
2935 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT;
2936
2937 size_t cpu_num = processor_count();
2938 size_t cpu_map_size = NCPUS / BitsPerCLong;
2939 size_t cpu_map_valid_size =
2940 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size);
2941
2942 cpu_to_node()->clear();
2943 cpu_to_node()->at_grow(cpu_num - 1);
2944
2945 size_t node_num = get_existing_num_nodes();
2946
2947 int distance = 0;
2948 int closest_distance = INT_MAX;
2949 int closest_node = 0;
2950 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal);
2951 for (size_t i = 0; i < node_num; i++) {
2952 // Check if node is configured (not a memory-less node). If it is not, find
2953 // the closest configured node. Check also if node is bound, i.e. it's allowed
2954 // to allocate memory from the node. If it's not allowed, map cpus in that node
2955 // to the closest node from which memory allocation is allowed.
2956 if (!isnode_in_configured_nodes(nindex_to_node()->at(i)) ||
2957 !isnode_in_bound_nodes(nindex_to_node()->at(i))) {
2958 closest_distance = INT_MAX;
2959 // Check distance from all remaining nodes in the system. Ignore distance
2960 // from itself, from another non-configured node, and from another non-bound
2961 // node.
2962 for (size_t m = 0; m < node_num; m++) {
2963 if (m != i &&
2964 isnode_in_configured_nodes(nindex_to_node()->at(m)) &&
2965 isnode_in_bound_nodes(nindex_to_node()->at(m))) {
2966 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m));
2967 // If a closest node is found, update. There is always at least one
2968 // configured and bound node in the system so there is always at least
2969 // one node close.
2970 if (distance != 0 && distance < closest_distance) {
2971 closest_distance = distance;
2972 closest_node = nindex_to_node()->at(m);
2973 }
2974 }
2975 }
2976 } else {
2977 // Current node is already a configured node.
2978 closest_node = nindex_to_node()->at(i);
2979 }
2980
2981 // Get cpus from the original node and map them to the closest node. If node
2982 // is a configured node (not a memory-less node), then original node and
2983 // closest node are the same.
2984 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) {
2985 for (size_t j = 0; j < cpu_map_valid_size; j++) {
2986 if (cpu_map[j] != 0) {
2987 for (size_t k = 0; k < BitsPerCLong; k++) {
2988 if (cpu_map[j] & (1UL << k)) {
2989 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node);
2990 }
2991 }
2992 }
2993 }
2994 }
2995 }
2996 FREE_C_HEAP_ARRAY(unsigned long, cpu_map);
2997 }
2998
2999 int os::Linux::get_node_by_cpu(int cpu_id) {
3000 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) {
3001 return cpu_to_node()->at(cpu_id);
3002 }
3003 return -1;
3004 }
3005
3006 GrowableArray<int>* os::Linux::_cpu_to_node;
3007 GrowableArray<int>* os::Linux::_nindex_to_node;
3008 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu;
3009 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus;
3010 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node;
3011 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes;
3012 os::Linux::numa_available_func_t os::Linux::_numa_available;
3013 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory;
3014 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory;
3015 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2;
3016 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy;
3017 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset;
3018 os::Linux::numa_distance_func_t os::Linux::_numa_distance;
3019 os::Linux::numa_get_membind_func_t os::Linux::_numa_get_membind;
3020 unsigned long* os::Linux::_numa_all_nodes;
3021 struct bitmask* os::Linux::_numa_all_nodes_ptr;
3022 struct bitmask* os::Linux::_numa_nodes_ptr;
3023
3024 bool os::pd_uncommit_memory(char* addr, size_t size) {
3025 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
3026 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
3027 return res != (uintptr_t) MAP_FAILED;
3028 }
3029
3030 static address get_stack_commited_bottom(address bottom, size_t size) {
3031 address nbot = bottom;
3032 address ntop = bottom + size;
3033
3034 size_t page_sz = os::vm_page_size();
3035 unsigned pages = size / page_sz;
3036
3037 unsigned char vec[1];
3038 unsigned imin = 1, imax = pages + 1, imid;
3039 int mincore_return_value = 0;
3040
3041 assert(imin <= imax, "Unexpected page size");
3042
3043 while (imin < imax) {
3044 imid = (imax + imin) / 2;
3045 nbot = ntop - (imid * page_sz);
3046
3047 // Use a trick with mincore to check whether the page is mapped or not.
3048 // mincore sets vec to 1 if page resides in memory and to 0 if page
3049 // is swapped output but if page we are asking for is unmapped
3050 // it returns -1,ENOMEM
3051 mincore_return_value = mincore(nbot, page_sz, vec);
3052
3053 if (mincore_return_value == -1) {
3054 // Page is not mapped go up
3055 // to find first mapped page
3056 if (errno != EAGAIN) {
3057 assert(errno == ENOMEM, "Unexpected mincore errno");
3058 imax = imid;
3059 }
3060 } else {
3061 // Page is mapped go down
3062 // to find first not mapped page
3063 imin = imid + 1;
3064 }
3065 }
3066
3067 nbot = nbot + page_sz;
3068
3069 // Adjust stack bottom one page up if last checked page is not mapped
3070 if (mincore_return_value == -1) {
3071 nbot = nbot + page_sz;
3072 }
3073
3074 return nbot;
3075 }
3076
3077 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
3078 int mincore_return_value;
3079 const size_t stripe = 1024; // query this many pages each time
3080 unsigned char vec[stripe + 1];
3081 // set a guard
3082 vec[stripe] = 'X';
3083
3084 const size_t page_sz = os::vm_page_size();
3085 size_t pages = size / page_sz;
3086
3087 assert(is_aligned(start, page_sz), "Start address must be page aligned");
3088 assert(is_aligned(size, page_sz), "Size must be page aligned");
3089
3090 committed_start = NULL;
3091
3092 int loops = (pages + stripe - 1) / stripe;
3093 int committed_pages = 0;
3094 address loop_base = start;
3095 bool found_range = false;
3096
3097 for (int index = 0; index < loops && !found_range; index ++) {
3098 assert(pages > 0, "Nothing to do");
3099 int pages_to_query = (pages >= stripe) ? stripe : pages;
3100 pages -= pages_to_query;
3101
3102 // Get stable read
3103 while ((mincore_return_value = mincore(loop_base, pages_to_query * page_sz, vec)) == -1 && errno == EAGAIN);
3104
3105 // During shutdown, some memory goes away without properly notifying NMT,
3106 // E.g. ConcurrentGCThread/WatcherThread can exit without deleting thread object.
3107 // Bailout and return as not committed for now.
3108 if (mincore_return_value == -1 && errno == ENOMEM) {
3109 return false;
3110 }
3111
3112 assert(vec[stripe] == 'X', "overflow guard");
3113 assert(mincore_return_value == 0, "Range must be valid");
3114 // Process this stripe
3115 for (int vecIdx = 0; vecIdx < pages_to_query; vecIdx ++) {
3116 if ((vec[vecIdx] & 0x01) == 0) { // not committed
3117 // End of current contiguous region
3118 if (committed_start != NULL) {
3119 found_range = true;
3120 break;
3121 }
3122 } else { // committed
3123 // Start of region
3124 if (committed_start == NULL) {
3125 committed_start = loop_base + page_sz * vecIdx;
3126 }
3127 committed_pages ++;
3128 }
3129 }
3130
3131 loop_base += pages_to_query * page_sz;
3132 }
3133
3134 if (committed_start != NULL) {
3135 assert(committed_pages > 0, "Must have committed region");
3136 assert(committed_pages <= int(size / page_sz), "Can not commit more than it has");
3137 assert(committed_start >= start && committed_start < start + size, "Out of range");
3138 committed_size = page_sz * committed_pages;
3139 return true;
3140 } else {
3141 assert(committed_pages == 0, "Should not have committed region");
3142 return false;
3143 }
3144 }
3145
3146
3147 // Linux uses a growable mapping for the stack, and if the mapping for
3148 // the stack guard pages is not removed when we detach a thread the
3149 // stack cannot grow beyond the pages where the stack guard was
3150 // mapped. If at some point later in the process the stack expands to
3151 // that point, the Linux kernel cannot expand the stack any further
3152 // because the guard pages are in the way, and a segfault occurs.
3153 //
3154 // However, it's essential not to split the stack region by unmapping
3155 // a region (leaving a hole) that's already part of the stack mapping,
3156 // so if the stack mapping has already grown beyond the guard pages at
3157 // the time we create them, we have to truncate the stack mapping.
3158 // So, we need to know the extent of the stack mapping when
3159 // create_stack_guard_pages() is called.
3160
3161 // We only need this for stacks that are growable: at the time of
3162 // writing thread stacks don't use growable mappings (i.e. those
3163 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this
3164 // only applies to the main thread.
3165
3166 // If the (growable) stack mapping already extends beyond the point
3167 // where we're going to put our guard pages, truncate the mapping at
3168 // that point by munmap()ping it. This ensures that when we later
3169 // munmap() the guard pages we don't leave a hole in the stack
3170 // mapping. This only affects the main/primordial thread
3171
3172 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
3173 if (os::is_primordial_thread()) {
3174 // As we manually grow stack up to bottom inside create_attached_thread(),
3175 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and
3176 // we don't need to do anything special.
3177 // Check it first, before calling heavy function.
3178 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom();
3179 unsigned char vec[1];
3180
3181 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) {
3182 // Fallback to slow path on all errors, including EAGAIN
3183 stack_extent = (uintptr_t) get_stack_commited_bottom(
3184 os::Linux::initial_thread_stack_bottom(),
3185 (size_t)addr - stack_extent);
3186 }
3187
3188 if (stack_extent < (uintptr_t)addr) {
3189 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent));
3190 }
3191 }
3192
3193 return os::commit_memory(addr, size, !ExecMem);
3194 }
3195
3196 // If this is a growable mapping, remove the guard pages entirely by
3197 // munmap()ping them. If not, just call uncommit_memory(). This only
3198 // affects the main/primordial thread, but guard against future OS changes.
3199 // It's safe to always unmap guard pages for primordial thread because we
3200 // always place it right after end of the mapped region.
3201
3202 bool os::remove_stack_guard_pages(char* addr, size_t size) {
3203 uintptr_t stack_extent, stack_base;
3204
3205 if (os::is_primordial_thread()) {
3206 return ::munmap(addr, size) == 0;
3207 }
3208
3209 return os::uncommit_memory(addr, size);
3210 }
3211
3212 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
3213 // at 'requested_addr'. If there are existing memory mappings at the same
3214 // location, however, they will be overwritten. If 'fixed' is false,
3215 // 'requested_addr' is only treated as a hint, the return value may or
3216 // may not start from the requested address. Unlike Linux mmap(), this
3217 // function returns NULL to indicate failure.
3218 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
3219 char * addr;
3220 int flags;
3221
3222 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
3223 if (fixed) {
3224 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address");
3225 flags |= MAP_FIXED;
3226 }
3227
3228 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
3229 // touch an uncommitted page. Otherwise, the read/write might
3230 // succeed if we have enough swap space to back the physical page.
3231 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
3232 flags, -1, 0);
3233
3234 return addr == MAP_FAILED ? NULL : addr;
3235 }
3236
3237 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address
3238 // (req_addr != NULL) or with a given alignment.
3239 // - bytes shall be a multiple of alignment.
3240 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3241 // - alignment sets the alignment at which memory shall be allocated.
3242 // It must be a multiple of allocation granularity.
3243 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3244 // req_addr or NULL.
3245 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) {
3246
3247 size_t extra_size = bytes;
3248 if (req_addr == NULL && alignment > 0) {
3249 extra_size += alignment;
3250 }
3251
3252 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE,
3253 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
3254 -1, 0);
3255 if (start == MAP_FAILED) {
3256 start = NULL;
3257 } else {
3258 if (req_addr != NULL) {
3259 if (start != req_addr) {
3260 ::munmap(start, extra_size);
3261 start = NULL;
3262 }
3263 } else {
3264 char* const start_aligned = align_up(start, alignment);
3265 char* const end_aligned = start_aligned + bytes;
3266 char* const end = start + extra_size;
3267 if (start_aligned > start) {
3268 ::munmap(start, start_aligned - start);
3269 }
3270 if (end_aligned < end) {
3271 ::munmap(end_aligned, end - end_aligned);
3272 }
3273 start = start_aligned;
3274 }
3275 }
3276 return start;
3277 }
3278
3279 static int anon_munmap(char * addr, size_t size) {
3280 return ::munmap(addr, size) == 0;
3281 }
3282
3283 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
3284 size_t alignment_hint) {
3285 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
3286 }
3287
3288 bool os::pd_release_memory(char* addr, size_t size) {
3289 return anon_munmap(addr, size);
3290 }
3291
3292 static bool linux_mprotect(char* addr, size_t size, int prot) {
3293 // Linux wants the mprotect address argument to be page aligned.
3294 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size());
3295
3296 // According to SUSv3, mprotect() should only be used with mappings
3297 // established by mmap(), and mmap() always maps whole pages. Unaligned
3298 // 'addr' likely indicates problem in the VM (e.g. trying to change
3299 // protection of malloc'ed or statically allocated memory). Check the
3300 // caller if you hit this assert.
3301 assert(addr == bottom, "sanity check");
3302
3303 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size());
3304 return ::mprotect(bottom, size, prot) == 0;
3305 }
3306
3307 // Set protections specified
3308 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
3309 bool is_committed) {
3310 unsigned int p = 0;
3311 switch (prot) {
3312 case MEM_PROT_NONE: p = PROT_NONE; break;
3313 case MEM_PROT_READ: p = PROT_READ; break;
3314 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
3315 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
3316 default:
3317 ShouldNotReachHere();
3318 }
3319 // is_committed is unused.
3320 return linux_mprotect(addr, bytes, p);
3321 }
3322
3323 bool os::guard_memory(char* addr, size_t size) {
3324 return linux_mprotect(addr, size, PROT_NONE);
3325 }
3326
3327 bool os::unguard_memory(char* addr, size_t size) {
3328 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE);
3329 }
3330
3331 bool os::Linux::transparent_huge_pages_sanity_check(bool warn,
3332 size_t page_size) {
3333 bool result = false;
3334 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,
3335 MAP_ANONYMOUS|MAP_PRIVATE,
3336 -1, 0);
3337 if (p != MAP_FAILED) {
3338 void *aligned_p = align_up(p, page_size);
3339
3340 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0;
3341
3342 munmap(p, page_size * 2);
3343 }
3344
3345 if (warn && !result) {
3346 warning("TransparentHugePages is not supported by the operating system.");
3347 }
3348
3349 return result;
3350 }
3351
3352 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) {
3353 bool result = false;
3354 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
3355 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB,
3356 -1, 0);
3357
3358 if (p != MAP_FAILED) {
3359 // We don't know if this really is a huge page or not.
3360 FILE *fp = fopen("/proc/self/maps", "r");
3361 if (fp) {
3362 while (!feof(fp)) {
3363 char chars[257];
3364 long x = 0;
3365 if (fgets(chars, sizeof(chars), fp)) {
3366 if (sscanf(chars, "%lx-%*x", &x) == 1
3367 && x == (long)p) {
3368 if (strstr (chars, "hugepage")) {
3369 result = true;
3370 break;
3371 }
3372 }
3373 }
3374 }
3375 fclose(fp);
3376 }
3377 munmap(p, page_size);
3378 }
3379
3380 if (warn && !result) {
3381 warning("HugeTLBFS is not supported by the operating system.");
3382 }
3383
3384 return result;
3385 }
3386
3387 // Set the coredump_filter bits to include largepages in core dump (bit 6)
3388 //
3389 // From the coredump_filter documentation:
3390 //
3391 // - (bit 0) anonymous private memory
3392 // - (bit 1) anonymous shared memory
3393 // - (bit 2) file-backed private memory
3394 // - (bit 3) file-backed shared memory
3395 // - (bit 4) ELF header pages in file-backed private memory areas (it is
3396 // effective only if the bit 2 is cleared)
3397 // - (bit 5) hugetlb private memory
3398 // - (bit 6) hugetlb shared memory
3399 // - (bit 7) dax private memory
3400 // - (bit 8) dax shared memory
3401 //
3402 static void set_coredump_filter(bool largepages, bool dax_shared) {
3403 FILE *f;
3404 long cdm;
3405 bool filter_changed = false;
3406
3407 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
3408 return;
3409 }
3410
3411 if (fscanf(f, "%lx", &cdm) != 1) {
3412 fclose(f);
3413 return;
3414 }
3415
3416 rewind(f);
3417
3418 if (largepages && (cdm & LARGEPAGES_BIT) == 0) {
3419 cdm |= LARGEPAGES_BIT;
3420 filter_changed = true;
3421 }
3422 if (dax_shared && (cdm & DAX_SHARED_BIT) == 0) {
3423 cdm |= DAX_SHARED_BIT;
3424 filter_changed = true;
3425 }
3426 if (filter_changed) {
3427 fprintf(f, "%#lx", cdm);
3428 }
3429
3430 fclose(f);
3431 }
3432
3433 // Large page support
3434
3435 static size_t _large_page_size = 0;
3436
3437 size_t os::Linux::find_large_page_size() {
3438 size_t large_page_size = 0;
3439
3440 // large_page_size on Linux is used to round up heap size. x86 uses either
3441 // 2M or 4M page, depending on whether PAE (Physical Address Extensions)
3442 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use
3443 // page as large as 256M.
3444 //
3445 // Here we try to figure out page size by parsing /proc/meminfo and looking
3446 // for a line with the following format:
3447 // Hugepagesize: 2048 kB
3448 //
3449 // If we can't determine the value (e.g. /proc is not mounted, or the text
3450 // format has been changed), we'll use the largest page size supported by
3451 // the processor.
3452
3453 #ifndef ZERO
3454 large_page_size =
3455 AARCH64_ONLY(2 * M)
3456 AMD64_ONLY(2 * M)
3457 ARM32_ONLY(2 * M)
3458 IA32_ONLY(4 * M)
3459 IA64_ONLY(256 * M)
3460 PPC_ONLY(4 * M)
3461 S390_ONLY(1 * M)
3462 SPARC_ONLY(4 * M);
3463 #endif // ZERO
3464
3465 FILE *fp = fopen("/proc/meminfo", "r");
3466 if (fp) {
3467 while (!feof(fp)) {
3468 int x = 0;
3469 char buf[16];
3470 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) {
3471 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) {
3472 large_page_size = x * K;
3473 break;
3474 }
3475 } else {
3476 // skip to next line
3477 for (;;) {
3478 int ch = fgetc(fp);
3479 if (ch == EOF || ch == (int)'\n') break;
3480 }
3481 }
3482 }
3483 fclose(fp);
3484 }
3485
3486 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) {
3487 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is "
3488 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size),
3489 proper_unit_for_byte_size(large_page_size));
3490 }
3491
3492 return large_page_size;
3493 }
3494
3495 size_t os::Linux::setup_large_page_size() {
3496 _large_page_size = Linux::find_large_page_size();
3497 const size_t default_page_size = (size_t)Linux::page_size();
3498 if (_large_page_size > default_page_size) {
3499 _page_sizes[0] = _large_page_size;
3500 _page_sizes[1] = default_page_size;
3501 _page_sizes[2] = 0;
3502 }
3503
3504 return _large_page_size;
3505 }
3506
3507 bool os::Linux::setup_large_page_type(size_t page_size) {
3508 if (FLAG_IS_DEFAULT(UseHugeTLBFS) &&
3509 FLAG_IS_DEFAULT(UseSHM) &&
3510 FLAG_IS_DEFAULT(UseTransparentHugePages)) {
3511
3512 // The type of large pages has not been specified by the user.
3513
3514 // Try UseHugeTLBFS and then UseSHM.
3515 UseHugeTLBFS = UseSHM = true;
3516
3517 // Don't try UseTransparentHugePages since there are known
3518 // performance issues with it turned on. This might change in the future.
3519 UseTransparentHugePages = false;
3520 }
3521
3522 if (UseTransparentHugePages) {
3523 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages);
3524 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) {
3525 UseHugeTLBFS = false;
3526 UseSHM = false;
3527 return true;
3528 }
3529 UseTransparentHugePages = false;
3530 }
3531
3532 if (UseHugeTLBFS) {
3533 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS);
3534 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) {
3535 UseSHM = false;
3536 return true;
3537 }
3538 UseHugeTLBFS = false;
3539 }
3540
3541 return UseSHM;
3542 }
3543
3544 void os::large_page_init() {
3545 if (!UseLargePages &&
3546 !UseTransparentHugePages &&
3547 !UseHugeTLBFS &&
3548 !UseSHM) {
3549 // Not using large pages.
3550 return;
3551 }
3552
3553 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) {
3554 // The user explicitly turned off large pages.
3555 // Ignore the rest of the large pages flags.
3556 UseTransparentHugePages = false;
3557 UseHugeTLBFS = false;
3558 UseSHM = false;
3559 return;
3560 }
3561
3562 size_t large_page_size = Linux::setup_large_page_size();
3563 UseLargePages = Linux::setup_large_page_type(large_page_size);
3564
3565 set_coredump_filter(true /*largepages*/, false /*dax_shared*/);
3566 }
3567
3568 #ifndef SHM_HUGETLB
3569 #define SHM_HUGETLB 04000
3570 #endif
3571
3572 #define shm_warning_format(format, ...) \
3573 do { \
3574 if (UseLargePages && \
3575 (!FLAG_IS_DEFAULT(UseLargePages) || \
3576 !FLAG_IS_DEFAULT(UseSHM) || \
3577 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \
3578 warning(format, __VA_ARGS__); \
3579 } \
3580 } while (0)
3581
3582 #define shm_warning(str) shm_warning_format("%s", str)
3583
3584 #define shm_warning_with_errno(str) \
3585 do { \
3586 int err = errno; \
3587 shm_warning_format(str " (error = %d)", err); \
3588 } while (0)
3589
3590 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) {
3591 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment");
3592
3593 if (!is_aligned(alignment, SHMLBA)) {
3594 assert(false, "Code below assumes that alignment is at least SHMLBA aligned");
3595 return NULL;
3596 }
3597
3598 // To ensure that we get 'alignment' aligned memory from shmat,
3599 // we pre-reserve aligned virtual memory and then attach to that.
3600
3601 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL);
3602 if (pre_reserved_addr == NULL) {
3603 // Couldn't pre-reserve aligned memory.
3604 shm_warning("Failed to pre-reserve aligned memory for shmat.");
3605 return NULL;
3606 }
3607
3608 // SHM_REMAP is needed to allow shmat to map over an existing mapping.
3609 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP);
3610
3611 if ((intptr_t)addr == -1) {
3612 int err = errno;
3613 shm_warning_with_errno("Failed to attach shared memory.");
3614
3615 assert(err != EACCES, "Unexpected error");
3616 assert(err != EIDRM, "Unexpected error");
3617 assert(err != EINVAL, "Unexpected error");
3618
3619 // Since we don't know if the kernel unmapped the pre-reserved memory area
3620 // we can't unmap it, since that would potentially unmap memory that was
3621 // mapped from other threads.
3622 return NULL;
3623 }
3624
3625 return addr;
3626 }
3627
3628 static char* shmat_at_address(int shmid, char* req_addr) {
3629 if (!is_aligned(req_addr, SHMLBA)) {
3630 assert(false, "Requested address needs to be SHMLBA aligned");
3631 return NULL;
3632 }
3633
3634 char* addr = (char*)shmat(shmid, req_addr, 0);
3635
3636 if ((intptr_t)addr == -1) {
3637 shm_warning_with_errno("Failed to attach shared memory.");
3638 return NULL;
3639 }
3640
3641 return addr;
3642 }
3643
3644 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) {
3645 // If a req_addr has been provided, we assume that the caller has already aligned the address.
3646 if (req_addr != NULL) {
3647 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size");
3648 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment");
3649 return shmat_at_address(shmid, req_addr);
3650 }
3651
3652 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically
3653 // return large page size aligned memory addresses when req_addr == NULL.
3654 // However, if the alignment is larger than the large page size, we have
3655 // to manually ensure that the memory returned is 'alignment' aligned.
3656 if (alignment > os::large_page_size()) {
3657 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size");
3658 return shmat_with_alignment(shmid, bytes, alignment);
3659 } else {
3660 return shmat_at_address(shmid, NULL);
3661 }
3662 }
3663
3664 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment,
3665 char* req_addr, bool exec) {
3666 // "exec" is passed in but not used. Creating the shared image for
3667 // the code cache doesn't have an SHM_X executable permission to check.
3668 assert(UseLargePages && UseSHM, "only for SHM large pages");
3669 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
3670 assert(is_aligned(req_addr, alignment), "Unaligned address");
3671
3672 if (!is_aligned(bytes, os::large_page_size())) {
3673 return NULL; // Fallback to small pages.
3674 }
3675
3676 // Create a large shared memory region to attach to based on size.
3677 // Currently, size is the total size of the heap.
3678 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);
3679 if (shmid == -1) {
3680 // Possible reasons for shmget failure:
3681 // 1. shmmax is too small for Java heap.
3682 // > check shmmax value: cat /proc/sys/kernel/shmmax
3683 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
3684 // 2. not enough large page memory.
3685 // > check available large pages: cat /proc/meminfo
3686 // > increase amount of large pages:
3687 // echo new_value > /proc/sys/vm/nr_hugepages
3688 // Note 1: different Linux may use different name for this property,
3689 // e.g. on Redhat AS-3 it is "hugetlb_pool".
3690 // Note 2: it's possible there's enough physical memory available but
3691 // they are so fragmented after a long run that they can't
3692 // coalesce into large pages. Try to reserve large pages when
3693 // the system is still "fresh".
3694 shm_warning_with_errno("Failed to reserve shared memory.");
3695 return NULL;
3696 }
3697
3698 // Attach to the region.
3699 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr);
3700
3701 // Remove shmid. If shmat() is successful, the actual shared memory segment
3702 // will be deleted when it's detached by shmdt() or when the process
3703 // terminates. If shmat() is not successful this will remove the shared
3704 // segment immediately.
3705 shmctl(shmid, IPC_RMID, NULL);
3706
3707 return addr;
3708 }
3709
3710 static void warn_on_large_pages_failure(char* req_addr, size_t bytes,
3711 int error) {
3712 assert(error == ENOMEM, "Only expect to fail if no memory is available");
3713
3714 bool warn_on_failure = UseLargePages &&
3715 (!FLAG_IS_DEFAULT(UseLargePages) ||
3716 !FLAG_IS_DEFAULT(UseHugeTLBFS) ||
3717 !FLAG_IS_DEFAULT(LargePageSizeInBytes));
3718
3719 if (warn_on_failure) {
3720 char msg[128];
3721 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: "
3722 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error);
3723 warning("%s", msg);
3724 }
3725 }
3726
3727 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes,
3728 char* req_addr,
3729 bool exec) {
3730 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
3731 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size");
3732 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
3733
3734 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
3735 char* addr = (char*)::mmap(req_addr, bytes, prot,
3736 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB,
3737 -1, 0);
3738
3739 if (addr == MAP_FAILED) {
3740 warn_on_large_pages_failure(req_addr, bytes, errno);
3741 return NULL;
3742 }
3743
3744 assert(is_aligned(addr, os::large_page_size()), "Must be");
3745
3746 return addr;
3747 }
3748
3749 // Reserve memory using mmap(MAP_HUGETLB).
3750 // - bytes shall be a multiple of alignment.
3751 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3752 // - alignment sets the alignment at which memory shall be allocated.
3753 // It must be a multiple of allocation granularity.
3754 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3755 // req_addr or NULL.
3756 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes,
3757 size_t alignment,
3758 char* req_addr,
3759 bool exec) {
3760 size_t large_page_size = os::large_page_size();
3761 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes");
3762
3763 assert(is_aligned(req_addr, alignment), "Must be");
3764 assert(is_aligned(bytes, alignment), "Must be");
3765
3766 // First reserve - but not commit - the address range in small pages.
3767 char* const start = anon_mmap_aligned(bytes, alignment, req_addr);
3768
3769 if (start == NULL) {
3770 return NULL;
3771 }
3772
3773 assert(is_aligned(start, alignment), "Must be");
3774
3775 char* end = start + bytes;
3776
3777 // Find the regions of the allocated chunk that can be promoted to large pages.
3778 char* lp_start = align_up(start, large_page_size);
3779 char* lp_end = align_down(end, large_page_size);
3780
3781 size_t lp_bytes = lp_end - lp_start;
3782
3783 assert(is_aligned(lp_bytes, large_page_size), "Must be");
3784
3785 if (lp_bytes == 0) {
3786 // The mapped region doesn't even span the start and the end of a large page.
3787 // Fall back to allocate a non-special area.
3788 ::munmap(start, end - start);
3789 return NULL;
3790 }
3791
3792 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
3793
3794 void* result;
3795
3796 // Commit small-paged leading area.
3797 if (start != lp_start) {
3798 result = ::mmap(start, lp_start - start, prot,
3799 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
3800 -1, 0);
3801 if (result == MAP_FAILED) {
3802 ::munmap(lp_start, end - lp_start);
3803 return NULL;
3804 }
3805 }
3806
3807 // Commit large-paged area.
3808 result = ::mmap(lp_start, lp_bytes, prot,
3809 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB,
3810 -1, 0);
3811 if (result == MAP_FAILED) {
3812 warn_on_large_pages_failure(lp_start, lp_bytes, errno);
3813 // If the mmap above fails, the large pages region will be unmapped and we
3814 // have regions before and after with small pages. Release these regions.
3815 //
3816 // | mapped | unmapped | mapped |
3817 // ^ ^ ^ ^
3818 // start lp_start lp_end end
3819 //
3820 ::munmap(start, lp_start - start);
3821 ::munmap(lp_end, end - lp_end);
3822 return NULL;
3823 }
3824
3825 // Commit small-paged trailing area.
3826 if (lp_end != end) {
3827 result = ::mmap(lp_end, end - lp_end, prot,
3828 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
3829 -1, 0);
3830 if (result == MAP_FAILED) {
3831 ::munmap(start, lp_end - start);
3832 return NULL;
3833 }
3834 }
3835
3836 return start;
3837 }
3838
3839 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes,
3840 size_t alignment,
3841 char* req_addr,
3842 bool exec) {
3843 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
3844 assert(is_aligned(req_addr, alignment), "Must be");
3845 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be");
3846 assert(is_power_of_2(os::large_page_size()), "Must be");
3847 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes");
3848
3849 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) {
3850 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec);
3851 } else {
3852 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec);
3853 }
3854 }
3855
3856 char* os::reserve_memory_special(size_t bytes, size_t alignment,
3857 char* req_addr, bool exec) {
3858 assert(UseLargePages, "only for large pages");
3859
3860 char* addr;
3861 if (UseSHM) {
3862 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec);
3863 } else {
3864 assert(UseHugeTLBFS, "must be");
3865 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec);
3866 }
3867
3868 if (addr != NULL) {
3869 if (UseNUMAInterleaving) {
3870 numa_make_global(addr, bytes);
3871 }
3872
3873 // The memory is committed
3874 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
3875 }
3876
3877 return addr;
3878 }
3879
3880 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) {
3881 // detaching the SHM segment will also delete it, see reserve_memory_special_shm()
3882 return shmdt(base) == 0;
3883 }
3884
3885 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) {
3886 return pd_release_memory(base, bytes);
3887 }
3888
3889 bool os::release_memory_special(char* base, size_t bytes) {
3890 bool res;
3891 if (MemTracker::tracking_level() > NMT_minimal) {
3892 Tracker tkr(Tracker::release);
3893 res = os::Linux::release_memory_special_impl(base, bytes);
3894 if (res) {
3895 tkr.record((address)base, bytes);
3896 }
3897
3898 } else {
3899 res = os::Linux::release_memory_special_impl(base, bytes);
3900 }
3901 return res;
3902 }
3903
3904 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) {
3905 assert(UseLargePages, "only for large pages");
3906 bool res;
3907
3908 if (UseSHM) {
3909 res = os::Linux::release_memory_special_shm(base, bytes);
3910 } else {
3911 assert(UseHugeTLBFS, "must be");
3912 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes);
3913 }
3914 return res;
3915 }
3916
3917 size_t os::large_page_size() {
3918 return _large_page_size;
3919 }
3920
3921 // With SysV SHM the entire memory region must be allocated as shared
3922 // memory.
3923 // HugeTLBFS allows application to commit large page memory on demand.
3924 // However, when committing memory with HugeTLBFS fails, the region
3925 // that was supposed to be committed will lose the old reservation
3926 // and allow other threads to steal that memory region. Because of this
3927 // behavior we can't commit HugeTLBFS memory.
3928 bool os::can_commit_large_page_memory() {
3929 return UseTransparentHugePages;
3930 }
3931
3932 bool os::can_execute_large_page_memory() {
3933 return UseTransparentHugePages || UseHugeTLBFS;
3934 }
3935
3936 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
3937 assert(file_desc >= 0, "file_desc is not valid");
3938 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
3939 if (result != NULL) {
3940 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
3941 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
3942 }
3943 }
3944 return result;
3945 }
3946
3947 // Reserve memory at an arbitrary address, only if that area is
3948 // available (and not reserved for something else).
3949
3950 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
3951 const int max_tries = 10;
3952 char* base[max_tries];
3953 size_t size[max_tries];
3954 const size_t gap = 0x000000;
3955
3956 // Assert only that the size is a multiple of the page size, since
3957 // that's all that mmap requires, and since that's all we really know
3958 // about at this low abstraction level. If we need higher alignment,
3959 // we can either pass an alignment to this method or verify alignment
3960 // in one of the methods further up the call chain. See bug 5044738.
3961 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
3962
3963 // Repeatedly allocate blocks until the block is allocated at the
3964 // right spot.
3965
3966 // Linux mmap allows caller to pass an address as hint; give it a try first,
3967 // if kernel honors the hint then we can return immediately.
3968 char * addr = anon_mmap(requested_addr, bytes, false);
3969 if (addr == requested_addr) {
3970 return requested_addr;
3971 }
3972
3973 if (addr != NULL) {
3974 // mmap() is successful but it fails to reserve at the requested address
3975 anon_munmap(addr, bytes);
3976 }
3977
3978 int i;
3979 for (i = 0; i < max_tries; ++i) {
3980 base[i] = reserve_memory(bytes);
3981
3982 if (base[i] != NULL) {
3983 // Is this the block we wanted?
3984 if (base[i] == requested_addr) {
3985 size[i] = bytes;
3986 break;
3987 }
3988
3989 // Does this overlap the block we wanted? Give back the overlapped
3990 // parts and try again.
3991
3992 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i];
3993 if (top_overlap >= 0 && (size_t)top_overlap < bytes) {
3994 unmap_memory(base[i], top_overlap);
3995 base[i] += top_overlap;
3996 size[i] = bytes - top_overlap;
3997 } else {
3998 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr;
3999 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) {
4000 unmap_memory(requested_addr, bottom_overlap);
4001 size[i] = bytes - bottom_overlap;
4002 } else {
4003 size[i] = bytes;
4004 }
4005 }
4006 }
4007 }
4008
4009 // Give back the unused reserved pieces.
4010
4011 for (int j = 0; j < i; ++j) {
4012 if (base[j] != NULL) {
4013 unmap_memory(base[j], size[j]);
4014 }
4015 }
4016
4017 if (i < max_tries) {
4018 return requested_addr;
4019 } else {
4020 return NULL;
4021 }
4022 }
4023
4024 size_t os::read(int fd, void *buf, unsigned int nBytes) {
4025 return ::read(fd, buf, nBytes);
4026 }
4027
4028 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
4029 return ::pread(fd, buf, nBytes, offset);
4030 }
4031
4032 // Short sleep, direct OS call.
4033 //
4034 // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee
4035 // sched_yield(2) will actually give up the CPU:
4036 //
4037 // * Alone on this pariticular CPU, keeps running.
4038 // * Before the introduction of "skip_buddy" with "compat_yield" disabled
4039 // (pre 2.6.39).
4040 //
4041 // So calling this with 0 is an alternative.
4042 //
4043 void os::naked_short_sleep(jlong ms) {
4044 struct timespec req;
4045
4046 assert(ms < 1000, "Un-interruptable sleep, short time use only");
4047 req.tv_sec = 0;
4048 if (ms > 0) {
4049 req.tv_nsec = (ms % 1000) * 1000000;
4050 } else {
4051 req.tv_nsec = 1;
4052 }
4053
4054 nanosleep(&req, NULL);
4055
4056 return;
4057 }
4058
4059 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
4060 void os::infinite_sleep() {
4061 while (true) { // sleep forever ...
4062 ::sleep(100); // ... 100 seconds at a time
4063 }
4064 }
4065
4066 // Used to convert frequent JVM_Yield() to nops
4067 bool os::dont_yield() {
4068 return DontYieldALot;
4069 }
4070
4071 void os::naked_yield() {
4072 sched_yield();
4073 }
4074
4075 ////////////////////////////////////////////////////////////////////////////////
4076 // thread priority support
4077
4078 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER
4079 // only supports dynamic priority, static priority must be zero. For real-time
4080 // applications, Linux supports SCHED_RR which allows static priority (1-99).
4081 // However, for large multi-threaded applications, SCHED_RR is not only slower
4082 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
4083 // of 5 runs - Sep 2005).
4084 //
4085 // The following code actually changes the niceness of kernel-thread/LWP. It
4086 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
4087 // not the entire user process, and user level threads are 1:1 mapped to kernel
4088 // threads. It has always been the case, but could change in the future. For
4089 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
4090 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
4091
4092 int os::java_to_os_priority[CriticalPriority + 1] = {
4093 19, // 0 Entry should never be used
4094
4095 4, // 1 MinPriority
4096 3, // 2
4097 2, // 3
4098
4099 1, // 4
4100 0, // 5 NormPriority
4101 -1, // 6
4102
4103 -2, // 7
4104 -3, // 8
4105 -4, // 9 NearMaxPriority
4106
4107 -5, // 10 MaxPriority
4108
4109 -5 // 11 CriticalPriority
4110 };
4111
4112 static int prio_init() {
4113 if (ThreadPriorityPolicy == 1) {
4114 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
4115 // if effective uid is not root. Perhaps, a more elegant way of doing
4116 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
4117 if (geteuid() != 0) {
4118 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
4119 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux");
4120 }
4121 ThreadPriorityPolicy = 0;
4122 }
4123 }
4124 if (UseCriticalJavaThreadPriority) {
4125 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
4126 }
4127 return 0;
4128 }
4129
4130 OSReturn os::set_native_priority(Thread* thread, int newpri) {
4131 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
4132
4133 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
4134 return (ret == 0) ? OS_OK : OS_ERR;
4135 }
4136
4137 OSReturn os::get_native_priority(const Thread* const thread,
4138 int *priority_ptr) {
4139 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
4140 *priority_ptr = java_to_os_priority[NormPriority];
4141 return OS_OK;
4142 }
4143
4144 errno = 0;
4145 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
4146 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
4147 }
4148
4149 ////////////////////////////////////////////////////////////////////////////////
4150 // suspend/resume support
4151
4152 // The low-level signal-based suspend/resume support is a remnant from the
4153 // old VM-suspension that used to be for java-suspension, safepoints etc,
4154 // within hotspot. Currently used by JFR's OSThreadSampler
4155 //
4156 // The remaining code is greatly simplified from the more general suspension
4157 // code that used to be used.
4158 //
4159 // The protocol is quite simple:
4160 // - suspend:
4161 // - sends a signal to the target thread
4162 // - polls the suspend state of the osthread using a yield loop
4163 // - target thread signal handler (SR_handler) sets suspend state
4164 // and blocks in sigsuspend until continued
4165 // - resume:
4166 // - sets target osthread state to continue
4167 // - sends signal to end the sigsuspend loop in the SR_handler
4168 //
4169 // Note that the SR_lock plays no role in this suspend/resume protocol,
4170 // but is checked for NULL in SR_handler as a thread termination indicator.
4171 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
4172 //
4173 // Note that resume_clear_context() and suspend_save_context() are needed
4174 // by SR_handler(), so that fetch_frame_from_ucontext() works,
4175 // which in part is used by:
4176 // - Forte Analyzer: AsyncGetCallTrace()
4177 // - StackBanging: get_frame_at_stack_banging_point()
4178
4179 static void resume_clear_context(OSThread *osthread) {
4180 osthread->set_ucontext(NULL);
4181 osthread->set_siginfo(NULL);
4182 }
4183
4184 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo,
4185 ucontext_t* context) {
4186 osthread->set_ucontext(context);
4187 osthread->set_siginfo(siginfo);
4188 }
4189
4190 // Handler function invoked when a thread's execution is suspended or
4191 // resumed. We have to be careful that only async-safe functions are
4192 // called here (Note: most pthread functions are not async safe and
4193 // should be avoided.)
4194 //
4195 // Note: sigwait() is a more natural fit than sigsuspend() from an
4196 // interface point of view, but sigwait() prevents the signal hander
4197 // from being run. libpthread would get very confused by not having
4198 // its signal handlers run and prevents sigwait()'s use with the
4199 // mutex granting granting signal.
4200 //
4201 // Currently only ever called on the VMThread and JavaThreads (PC sampling)
4202 //
4203 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
4204 // Save and restore errno to avoid confusing native code with EINTR
4205 // after sigsuspend.
4206 int old_errno = errno;
4207
4208 Thread* thread = Thread::current_or_null_safe();
4209 assert(thread != NULL, "Missing current thread in SR_handler");
4210
4211 // On some systems we have seen signal delivery get "stuck" until the signal
4212 // mask is changed as part of thread termination. Check that the current thread
4213 // has not already terminated (via SR_lock()) - else the following assertion
4214 // will fail because the thread is no longer a JavaThread as the ~JavaThread
4215 // destructor has completed.
4216
4217 if (thread->SR_lock() == NULL) {
4218 return;
4219 }
4220
4221 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
4222
4223 OSThread* osthread = thread->osthread();
4224
4225 os::SuspendResume::State current = osthread->sr.state();
4226 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
4227 suspend_save_context(osthread, siginfo, context);
4228
4229 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
4230 os::SuspendResume::State state = osthread->sr.suspended();
4231 if (state == os::SuspendResume::SR_SUSPENDED) {
4232 sigset_t suspend_set; // signals for sigsuspend()
4233 sigemptyset(&suspend_set);
4234 // get current set of blocked signals and unblock resume signal
4235 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
4236 sigdelset(&suspend_set, SR_signum);
4237
4238 sr_semaphore.signal();
4239 // wait here until we are resumed
4240 while (1) {
4241 sigsuspend(&suspend_set);
4242
4243 os::SuspendResume::State result = osthread->sr.running();
4244 if (result == os::SuspendResume::SR_RUNNING) {
4245 sr_semaphore.signal();
4246 break;
4247 }
4248 }
4249
4250 } else if (state == os::SuspendResume::SR_RUNNING) {
4251 // request was cancelled, continue
4252 } else {
4253 ShouldNotReachHere();
4254 }
4255
4256 resume_clear_context(osthread);
4257 } else if (current == os::SuspendResume::SR_RUNNING) {
4258 // request was cancelled, continue
4259 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
4260 // ignore
4261 } else {
4262 // ignore
4263 }
4264
4265 errno = old_errno;
4266 }
4267
4268 static int SR_initialize() {
4269 struct sigaction act;
4270 char *s;
4271
4272 // Get signal number to use for suspend/resume
4273 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
4274 int sig = ::strtol(s, 0, 10);
4275 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769.
4276 sig < NSIG) { // Must be legal signal and fit into sigflags[].
4277 SR_signum = sig;
4278 } else {
4279 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
4280 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
4281 }
4282 }
4283
4284 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
4285 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
4286
4287 sigemptyset(&SR_sigset);
4288 sigaddset(&SR_sigset, SR_signum);
4289
4290 // Set up signal handler for suspend/resume
4291 act.sa_flags = SA_RESTART|SA_SIGINFO;
4292 act.sa_handler = (void (*)(int)) SR_handler;
4293
4294 // SR_signum is blocked by default.
4295 // 4528190 - We also need to block pthread restart signal (32 on all
4296 // supported Linux platforms). Note that LinuxThreads need to block
4297 // this signal for all threads to work properly. So we don't have
4298 // to use hard-coded signal number when setting up the mask.
4299 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
4300
4301 if (sigaction(SR_signum, &act, 0) == -1) {
4302 return -1;
4303 }
4304
4305 // Save signal flag
4306 os::Linux::set_our_sigflags(SR_signum, act.sa_flags);
4307 return 0;
4308 }
4309
4310 static int sr_notify(OSThread* osthread) {
4311 int status = pthread_kill(osthread->pthread_id(), SR_signum);
4312 assert_status(status == 0, status, "pthread_kill");
4313 return status;
4314 }
4315
4316 // "Randomly" selected value for how long we want to spin
4317 // before bailing out on suspending a thread, also how often
4318 // we send a signal to a thread we want to resume
4319 static const int RANDOMLY_LARGE_INTEGER = 1000000;
4320 static const int RANDOMLY_LARGE_INTEGER2 = 100;
4321
4322 // returns true on success and false on error - really an error is fatal
4323 // but this seems the normal response to library errors
4324 static bool do_suspend(OSThread* osthread) {
4325 assert(osthread->sr.is_running(), "thread should be running");
4326 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
4327
4328 // mark as suspended and send signal
4329 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
4330 // failed to switch, state wasn't running?
4331 ShouldNotReachHere();
4332 return false;
4333 }
4334
4335 if (sr_notify(osthread) != 0) {
4336 ShouldNotReachHere();
4337 }
4338
4339 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
4340 while (true) {
4341 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) {
4342 break;
4343 } else {
4344 // timeout
4345 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
4346 if (cancelled == os::SuspendResume::SR_RUNNING) {
4347 return false;
4348 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
4349 // make sure that we consume the signal on the semaphore as well
4350 sr_semaphore.wait();
4351 break;
4352 } else {
4353 ShouldNotReachHere();
4354 return false;
4355 }
4356 }
4357 }
4358
4359 guarantee(osthread->sr.is_suspended(), "Must be suspended");
4360 return true;
4361 }
4362
4363 static void do_resume(OSThread* osthread) {
4364 assert(osthread->sr.is_suspended(), "thread should be suspended");
4365 assert(!sr_semaphore.trywait(), "invalid semaphore state");
4366
4367 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
4368 // failed to switch to WAKEUP_REQUEST
4369 ShouldNotReachHere();
4370 return;
4371 }
4372
4373 while (true) {
4374 if (sr_notify(osthread) == 0) {
4375 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) {
4376 if (osthread->sr.is_running()) {
4377 return;
4378 }
4379 }
4380 } else {
4381 ShouldNotReachHere();
4382 }
4383 }
4384
4385 guarantee(osthread->sr.is_running(), "Must be running!");
4386 }
4387
4388 ///////////////////////////////////////////////////////////////////////////////////
4389 // signal handling (except suspend/resume)
4390
4391 // This routine may be used by user applications as a "hook" to catch signals.
4392 // The user-defined signal handler must pass unrecognized signals to this
4393 // routine, and if it returns true (non-zero), then the signal handler must
4394 // return immediately. If the flag "abort_if_unrecognized" is true, then this
4395 // routine will never retun false (zero), but instead will execute a VM panic
4396 // routine kill the process.
4397 //
4398 // If this routine returns false, it is OK to call it again. This allows
4399 // the user-defined signal handler to perform checks either before or after
4400 // the VM performs its own checks. Naturally, the user code would be making
4401 // a serious error if it tried to handle an exception (such as a null check
4402 // or breakpoint) that the VM was generating for its own correct operation.
4403 //
4404 // This routine may recognize any of the following kinds of signals:
4405 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
4406 // It should be consulted by handlers for any of those signals.
4407 //
4408 // The caller of this routine must pass in the three arguments supplied
4409 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
4410 // field of the structure passed to sigaction(). This routine assumes that
4411 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
4412 //
4413 // Note that the VM will print warnings if it detects conflicting signal
4414 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
4415 //
4416 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo,
4417 siginfo_t* siginfo,
4418 void* ucontext,
4419 int abort_if_unrecognized);
4420
4421 static void signalHandler(int sig, siginfo_t* info, void* uc) {
4422 assert(info != NULL && uc != NULL, "it must be old kernel");
4423 int orig_errno = errno; // Preserve errno value over signal handler.
4424 JVM_handle_linux_signal(sig, info, uc, true);
4425 errno = orig_errno;
4426 }
4427
4428
4429 // This boolean allows users to forward their own non-matching signals
4430 // to JVM_handle_linux_signal, harmlessly.
4431 bool os::Linux::signal_handlers_are_installed = false;
4432
4433 // For signal-chaining
4434 struct sigaction sigact[NSIG];
4435 uint64_t sigs = 0;
4436 #if (64 < NSIG-1)
4437 #error "Not all signals can be encoded in sigs. Adapt its type!"
4438 #endif
4439 bool os::Linux::libjsig_is_loaded = false;
4440 typedef struct sigaction *(*get_signal_t)(int);
4441 get_signal_t os::Linux::get_signal_action = NULL;
4442
4443 struct sigaction* os::Linux::get_chained_signal_action(int sig) {
4444 struct sigaction *actp = NULL;
4445
4446 if (libjsig_is_loaded) {
4447 // Retrieve the old signal handler from libjsig
4448 actp = (*get_signal_action)(sig);
4449 }
4450 if (actp == NULL) {
4451 // Retrieve the preinstalled signal handler from jvm
4452 actp = get_preinstalled_handler(sig);
4453 }
4454
4455 return actp;
4456 }
4457
4458 static bool call_chained_handler(struct sigaction *actp, int sig,
4459 siginfo_t *siginfo, void *context) {
4460 // Call the old signal handler
4461 if (actp->sa_handler == SIG_DFL) {
4462 // It's more reasonable to let jvm treat it as an unexpected exception
4463 // instead of taking the default action.
4464 return false;
4465 } else if (actp->sa_handler != SIG_IGN) {
4466 if ((actp->sa_flags & SA_NODEFER) == 0) {
4467 // automaticlly block the signal
4468 sigaddset(&(actp->sa_mask), sig);
4469 }
4470
4471 sa_handler_t hand = NULL;
4472 sa_sigaction_t sa = NULL;
4473 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
4474 // retrieve the chained handler
4475 if (siginfo_flag_set) {
4476 sa = actp->sa_sigaction;
4477 } else {
4478 hand = actp->sa_handler;
4479 }
4480
4481 if ((actp->sa_flags & SA_RESETHAND) != 0) {
4482 actp->sa_handler = SIG_DFL;
4483 }
4484
4485 // try to honor the signal mask
4486 sigset_t oset;
4487 sigemptyset(&oset);
4488 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
4489
4490 // call into the chained handler
4491 if (siginfo_flag_set) {
4492 (*sa)(sig, siginfo, context);
4493 } else {
4494 (*hand)(sig);
4495 }
4496
4497 // restore the signal mask
4498 pthread_sigmask(SIG_SETMASK, &oset, NULL);
4499 }
4500 // Tell jvm's signal handler the signal is taken care of.
4501 return true;
4502 }
4503
4504 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) {
4505 bool chained = false;
4506 // signal-chaining
4507 if (UseSignalChaining) {
4508 struct sigaction *actp = get_chained_signal_action(sig);
4509 if (actp != NULL) {
4510 chained = call_chained_handler(actp, sig, siginfo, context);
4511 }
4512 }
4513 return chained;
4514 }
4515
4516 struct sigaction* os::Linux::get_preinstalled_handler(int sig) {
4517 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) {
4518 return &sigact[sig];
4519 }
4520 return NULL;
4521 }
4522
4523 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
4524 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4525 sigact[sig] = oldAct;
4526 sigs |= (uint64_t)1 << (sig-1);
4527 }
4528
4529 // for diagnostic
4530 int sigflags[NSIG];
4531
4532 int os::Linux::get_our_sigflags(int sig) {
4533 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4534 return sigflags[sig];
4535 }
4536
4537 void os::Linux::set_our_sigflags(int sig, int flags) {
4538 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4539 if (sig > 0 && sig < NSIG) {
4540 sigflags[sig] = flags;
4541 }
4542 }
4543
4544 void os::Linux::set_signal_handler(int sig, bool set_installed) {
4545 // Check for overwrite.
4546 struct sigaction oldAct;
4547 sigaction(sig, (struct sigaction*)NULL, &oldAct);
4548
4549 void* oldhand = oldAct.sa_sigaction
4550 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4551 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4552 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
4553 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
4554 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
4555 if (AllowUserSignalHandlers || !set_installed) {
4556 // Do not overwrite; user takes responsibility to forward to us.
4557 return;
4558 } else if (UseSignalChaining) {
4559 // save the old handler in jvm
4560 save_preinstalled_handler(sig, oldAct);
4561 // libjsig also interposes the sigaction() call below and saves the
4562 // old sigaction on it own.
4563 } else {
4564 fatal("Encountered unexpected pre-existing sigaction handler "
4565 "%#lx for signal %d.", (long)oldhand, sig);
4566 }
4567 }
4568
4569 struct sigaction sigAct;
4570 sigfillset(&(sigAct.sa_mask));
4571 sigAct.sa_handler = SIG_DFL;
4572 if (!set_installed) {
4573 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4574 } else {
4575 sigAct.sa_sigaction = signalHandler;
4576 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4577 }
4578 // Save flags, which are set by ours
4579 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4580 sigflags[sig] = sigAct.sa_flags;
4581
4582 int ret = sigaction(sig, &sigAct, &oldAct);
4583 assert(ret == 0, "check");
4584
4585 void* oldhand2 = oldAct.sa_sigaction
4586 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4587 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4588 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
4589 }
4590
4591 // install signal handlers for signals that HotSpot needs to
4592 // handle in order to support Java-level exception handling.
4593
4594 void os::Linux::install_signal_handlers() {
4595 if (!signal_handlers_are_installed) {
4596 signal_handlers_are_installed = true;
4597
4598 // signal-chaining
4599 typedef void (*signal_setting_t)();
4600 signal_setting_t begin_signal_setting = NULL;
4601 signal_setting_t end_signal_setting = NULL;
4602 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4603 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
4604 if (begin_signal_setting != NULL) {
4605 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4606 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
4607 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
4608 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
4609 libjsig_is_loaded = true;
4610 assert(UseSignalChaining, "should enable signal-chaining");
4611 }
4612 if (libjsig_is_loaded) {
4613 // Tell libjsig jvm is setting signal handlers
4614 (*begin_signal_setting)();
4615 }
4616
4617 set_signal_handler(SIGSEGV, true);
4618 set_signal_handler(SIGPIPE, true);
4619 set_signal_handler(SIGBUS, true);
4620 set_signal_handler(SIGILL, true);
4621 set_signal_handler(SIGFPE, true);
4622 #if defined(PPC64)
4623 set_signal_handler(SIGTRAP, true);
4624 #endif
4625 set_signal_handler(SIGXFSZ, true);
4626
4627 if (libjsig_is_loaded) {
4628 // Tell libjsig jvm finishes setting signal handlers
4629 (*end_signal_setting)();
4630 }
4631
4632 // We don't activate signal checker if libjsig is in place, we trust ourselves
4633 // and if UserSignalHandler is installed all bets are off.
4634 // Log that signal checking is off only if -verbose:jni is specified.
4635 if (CheckJNICalls) {
4636 if (libjsig_is_loaded) {
4637 if (PrintJNIResolving) {
4638 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
4639 }
4640 check_signals = false;
4641 }
4642 if (AllowUserSignalHandlers) {
4643 if (PrintJNIResolving) {
4644 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
4645 }
4646 check_signals = false;
4647 }
4648 }
4649 }
4650 }
4651
4652 // This is the fastest way to get thread cpu time on Linux.
4653 // Returns cpu time (user+sys) for any thread, not only for current.
4654 // POSIX compliant clocks are implemented in the kernels 2.6.16+.
4655 // It might work on 2.6.10+ with a special kernel/glibc patch.
4656 // For reference, please, see IEEE Std 1003.1-2004:
4657 // http://www.unix.org/single_unix_specification
4658
4659 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) {
4660 struct timespec tp;
4661 int rc = os::Posix::clock_gettime(clockid, &tp);
4662 assert(rc == 0, "clock_gettime is expected to return 0 code");
4663
4664 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec;
4665 }
4666
4667 void os::Linux::initialize_os_info() {
4668 assert(_os_version == 0, "OS info already initialized");
4669
4670 struct utsname _uname;
4671
4672 uint32_t major;
4673 uint32_t minor;
4674 uint32_t fix;
4675
4676 int rc;
4677
4678 // Kernel version is unknown if
4679 // verification below fails.
4680 _os_version = 0x01000000;
4681
4682 rc = uname(&_uname);
4683 if (rc != -1) {
4684
4685 rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix);
4686 if (rc == 3) {
4687
4688 if (major < 256 && minor < 256 && fix < 256) {
4689 // Kernel version format is as expected,
4690 // set it overriding unknown state.
4691 _os_version = (major << 16) |
4692 (minor << 8 ) |
4693 (fix << 0 ) ;
4694 }
4695 }
4696 }
4697 }
4698
4699 uint32_t os::Linux::os_version() {
4700 assert(_os_version != 0, "not initialized");
4701 return _os_version & 0x00FFFFFF;
4702 }
4703
4704 bool os::Linux::os_version_is_known() {
4705 assert(_os_version != 0, "not initialized");
4706 return _os_version & 0x01000000 ? false : true;
4707 }
4708
4709 /////
4710 // glibc on Linux platform uses non-documented flag
4711 // to indicate, that some special sort of signal
4712 // trampoline is used.
4713 // We will never set this flag, and we should
4714 // ignore this flag in our diagnostic
4715 #ifdef SIGNIFICANT_SIGNAL_MASK
4716 #undef SIGNIFICANT_SIGNAL_MASK
4717 #endif
4718 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
4719
4720 static const char* get_signal_handler_name(address handler,
4721 char* buf, int buflen) {
4722 int offset = 0;
4723 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
4724 if (found) {
4725 // skip directory names
4726 const char *p1, *p2;
4727 p1 = buf;
4728 size_t len = strlen(os::file_separator());
4729 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
4730 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
4731 } else {
4732 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
4733 }
4734 return buf;
4735 }
4736
4737 static void print_signal_handler(outputStream* st, int sig,
4738 char* buf, size_t buflen) {
4739 struct sigaction sa;
4740
4741 sigaction(sig, NULL, &sa);
4742
4743 // See comment for SIGNIFICANT_SIGNAL_MASK define
4744 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4745
4746 st->print("%s: ", os::exception_name(sig, buf, buflen));
4747
4748 address handler = (sa.sa_flags & SA_SIGINFO)
4749 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
4750 : CAST_FROM_FN_PTR(address, sa.sa_handler);
4751
4752 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
4753 st->print("SIG_DFL");
4754 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
4755 st->print("SIG_IGN");
4756 } else {
4757 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
4758 }
4759
4760 st->print(", sa_mask[0]=");
4761 os::Posix::print_signal_set_short(st, &sa.sa_mask);
4762
4763 address rh = VMError::get_resetted_sighandler(sig);
4764 // May be, handler was resetted by VMError?
4765 if (rh != NULL) {
4766 handler = rh;
4767 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
4768 }
4769
4770 st->print(", sa_flags=");
4771 os::Posix::print_sa_flags(st, sa.sa_flags);
4772
4773 // Check: is it our handler?
4774 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
4775 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
4776 // It is our signal handler
4777 // check for flags, reset system-used one!
4778 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) {
4779 st->print(
4780 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
4781 os::Linux::get_our_sigflags(sig));
4782 }
4783 }
4784 st->cr();
4785 }
4786
4787
4788 #define DO_SIGNAL_CHECK(sig) \
4789 do { \
4790 if (!sigismember(&check_signal_done, sig)) { \
4791 os::Linux::check_signal_handler(sig); \
4792 } \
4793 } while (0)
4794
4795 // This method is a periodic task to check for misbehaving JNI applications
4796 // under CheckJNI, we can add any periodic checks here
4797
4798 void os::run_periodic_checks() {
4799 if (check_signals == false) return;
4800
4801 // SEGV and BUS if overridden could potentially prevent
4802 // generation of hs*.log in the event of a crash, debugging
4803 // such a case can be very challenging, so we absolutely
4804 // check the following for a good measure:
4805 DO_SIGNAL_CHECK(SIGSEGV);
4806 DO_SIGNAL_CHECK(SIGILL);
4807 DO_SIGNAL_CHECK(SIGFPE);
4808 DO_SIGNAL_CHECK(SIGBUS);
4809 DO_SIGNAL_CHECK(SIGPIPE);
4810 DO_SIGNAL_CHECK(SIGXFSZ);
4811 #if defined(PPC64)
4812 DO_SIGNAL_CHECK(SIGTRAP);
4813 #endif
4814
4815 // ReduceSignalUsage allows the user to override these handlers
4816 // see comments at the very top and jvm_md.h
4817 if (!ReduceSignalUsage) {
4818 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
4819 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
4820 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
4821 DO_SIGNAL_CHECK(BREAK_SIGNAL);
4822 }
4823
4824 DO_SIGNAL_CHECK(SR_signum);
4825 }
4826
4827 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
4828
4829 static os_sigaction_t os_sigaction = NULL;
4830
4831 void os::Linux::check_signal_handler(int sig) {
4832 char buf[O_BUFLEN];
4833 address jvmHandler = NULL;
4834
4835
4836 struct sigaction act;
4837 if (os_sigaction == NULL) {
4838 // only trust the default sigaction, in case it has been interposed
4839 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
4840 if (os_sigaction == NULL) return;
4841 }
4842
4843 os_sigaction(sig, (struct sigaction*)NULL, &act);
4844
4845
4846 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4847
4848 address thisHandler = (act.sa_flags & SA_SIGINFO)
4849 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
4850 : CAST_FROM_FN_PTR(address, act.sa_handler);
4851
4852
4853 switch (sig) {
4854 case SIGSEGV:
4855 case SIGBUS:
4856 case SIGFPE:
4857 case SIGPIPE:
4858 case SIGILL:
4859 case SIGXFSZ:
4860 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
4861 break;
4862
4863 case SHUTDOWN1_SIGNAL:
4864 case SHUTDOWN2_SIGNAL:
4865 case SHUTDOWN3_SIGNAL:
4866 case BREAK_SIGNAL:
4867 jvmHandler = (address)user_handler();
4868 break;
4869
4870 default:
4871 if (sig == SR_signum) {
4872 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
4873 } else {
4874 return;
4875 }
4876 break;
4877 }
4878
4879 if (thisHandler != jvmHandler) {
4880 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
4881 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
4882 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
4883 // No need to check this sig any longer
4884 sigaddset(&check_signal_done, sig);
4885 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
4886 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
4887 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
4888 exception_name(sig, buf, O_BUFLEN));
4889 }
4890 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) {
4891 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
4892 tty->print("expected:");
4893 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig));
4894 tty->cr();
4895 tty->print(" found:");
4896 os::Posix::print_sa_flags(tty, act.sa_flags);
4897 tty->cr();
4898 // No need to check this sig any longer
4899 sigaddset(&check_signal_done, sig);
4900 }
4901
4902 // Dump all the signal
4903 if (sigismember(&check_signal_done, sig)) {
4904 print_signal_handlers(tty, buf, O_BUFLEN);
4905 }
4906 }
4907
4908 extern void report_error(char* file_name, int line_no, char* title,
4909 char* format, ...);
4910
4911 // this is called _before_ most of the global arguments have been parsed
4912 void os::init(void) {
4913 char dummy; // used to get a guess on initial stack address
4914
4915 clock_tics_per_sec = sysconf(_SC_CLK_TCK);
4916
4917 init_random(1234567);
4918
4919 Linux::set_page_size(sysconf(_SC_PAGESIZE));
4920 if (Linux::page_size() == -1) {
4921 fatal("os_linux.cpp: os::init: sysconf failed (%s)",
4922 os::strerror(errno));
4923 }
4924 init_page_sizes((size_t) Linux::page_size());
4925
4926 Linux::initialize_system_info();
4927
4928 Linux::initialize_os_info();
4929
4930 // _main_thread points to the thread that created/loaded the JVM.
4931 Linux::_main_thread = pthread_self();
4932
4933 // retrieve entry point for pthread_setname_np
4934 Linux::_pthread_setname_np =
4935 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np");
4936
4937 os::Posix::init();
4938
4939 initial_time_count = javaTimeNanos();
4940
4941 // Always warn if no monotonic clock available
4942 if (!os::Posix::supports_monotonic_clock()) {
4943 warning("No monotonic clock was available - timed services may " \
4944 "be adversely affected if the time-of-day clock changes");
4945 }
4946 }
4947
4948 // To install functions for atexit system call
4949 extern "C" {
4950 static void perfMemory_exit_helper() {
4951 perfMemory_exit();
4952 }
4953 }
4954
4955 void os::pd_init_container_support() {
4956 OSContainer::init();
4957 }
4958
4959 // this is called _after_ the global arguments have been parsed
4960 jint os::init_2(void) {
4961
4962 os::Posix::init_2();
4963
4964 Linux::fast_thread_clock_init();
4965
4966 // initialize suspend/resume support - must do this before signal_sets_init()
4967 if (SR_initialize() != 0) {
4968 perror("SR_initialize failed");
4969 return JNI_ERR;
4970 }
4971
4972 Linux::signal_sets_init();
4973 Linux::install_signal_handlers();
4974 // Initialize data for jdk.internal.misc.Signal
4975 if (!ReduceSignalUsage) {
4976 jdk_misc_signal_init();
4977 }
4978
4979 // Check and sets minimum stack sizes against command line options
4980 if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
4981 return JNI_ERR;
4982 }
4983
4984 suppress_primordial_thread_resolution = Arguments::created_by_java_launcher();
4985 if (!suppress_primordial_thread_resolution) {
4986 Linux::capture_initial_stack(JavaThread::stack_size_at_create());
4987 }
4988
4989 #if defined(IA32)
4990 workaround_expand_exec_shield_cs_limit();
4991 #endif
4992
4993 Linux::libpthread_init();
4994 Linux::sched_getcpu_init();
4995 log_info(os)("HotSpot is running with %s, %s",
4996 Linux::glibc_version(), Linux::libpthread_version());
4997
4998 if (UseNUMA) {
4999 if (!Linux::libnuma_init()) {
5000 UseNUMA = false;
5001 } else {
5002 if ((Linux::numa_max_node() < 1) || Linux::isbound_to_single_node()) {
5003 // If there's only one node (they start from 0) or if the process
5004 // is bound explicitly to a single node using membind, disable NUMA.
5005 UseNUMA = false;
5006 }
5007 }
5008
5009 if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) {
5010 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way
5011 // we can make the adaptive lgrp chunk resizing work. If the user specified both
5012 // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn
5013 // and disable adaptive resizing.
5014 if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) {
5015 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, "
5016 "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)");
5017 UseAdaptiveSizePolicy = false;
5018 UseAdaptiveNUMAChunkSizing = false;
5019 }
5020 }
5021
5022 if (!UseNUMA && ForceNUMA) {
5023 UseNUMA = true;
5024 }
5025 }
5026
5027 if (MaxFDLimit) {
5028 // set the number of file descriptors to max. print out error
5029 // if getrlimit/setrlimit fails but continue regardless.
5030 struct rlimit nbr_files;
5031 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
5032 if (status != 0) {
5033 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
5034 } else {
5035 nbr_files.rlim_cur = nbr_files.rlim_max;
5036 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
5037 if (status != 0) {
5038 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
5039 }
5040 }
5041 }
5042
5043 // Initialize lock used to serialize thread creation (see os::create_thread)
5044 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false));
5045
5046 // at-exit methods are called in the reverse order of their registration.
5047 // atexit functions are called on return from main or as a result of a
5048 // call to exit(3C). There can be only 32 of these functions registered
5049 // and atexit() does not set errno.
5050
5051 if (PerfAllowAtExitRegistration) {
5052 // only register atexit functions if PerfAllowAtExitRegistration is set.
5053 // atexit functions can be delayed until process exit time, which
5054 // can be problematic for embedded VM situations. Embedded VMs should
5055 // call DestroyJavaVM() to assure that VM resources are released.
5056
5057 // note: perfMemory_exit_helper atexit function may be removed in
5058 // the future if the appropriate cleanup code can be added to the
5059 // VM_Exit VMOperation's doit method.
5060 if (atexit(perfMemory_exit_helper) != 0) {
5061 warning("os::init_2 atexit(perfMemory_exit_helper) failed");
5062 }
5063 }
5064
5065 // initialize thread priority policy
5066 prio_init();
5067
5068 if (!FLAG_IS_DEFAULT(AllocateHeapAt)) {
5069 set_coredump_filter(false /*largepages*/, true /*dax_shared*/);
5070 }
5071 return JNI_OK;
5072 }
5073
5074 // Mark the polling page as unreadable
5075 void os::make_polling_page_unreadable(void) {
5076 if (!guard_memory((char*)_polling_page, Linux::page_size())) {
5077 fatal("Could not disable polling page");
5078 }
5079 }
5080
5081 // Mark the polling page as readable
5082 void os::make_polling_page_readable(void) {
5083 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) {
5084 fatal("Could not enable polling page");
5085 }
5086 }
5087
5088 // older glibc versions don't have this macro (which expands to
5089 // an optimized bit-counting function) so we have to roll our own
5090 #ifndef CPU_COUNT
5091
5092 static int _cpu_count(const cpu_set_t* cpus) {
5093 int count = 0;
5094 // only look up to the number of configured processors
5095 for (int i = 0; i < os::processor_count(); i++) {
5096 if (CPU_ISSET(i, cpus)) {
5097 count++;
5098 }
5099 }
5100 return count;
5101 }
5102
5103 #define CPU_COUNT(cpus) _cpu_count(cpus)
5104
5105 #endif // CPU_COUNT
5106
5107 // Get the current number of available processors for this process.
5108 // This value can change at any time during a process's lifetime.
5109 // sched_getaffinity gives an accurate answer as it accounts for cpusets.
5110 // If it appears there may be more than 1024 processors then we do a
5111 // dynamic check - see 6515172 for details.
5112 // If anything goes wrong we fallback to returning the number of online
5113 // processors - which can be greater than the number available to the process.
5114 int os::Linux::active_processor_count() {
5115 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors
5116 cpu_set_t* cpus_p = &cpus;
5117 int cpus_size = sizeof(cpu_set_t);
5118
5119 int configured_cpus = os::processor_count(); // upper bound on available cpus
5120 int cpu_count = 0;
5121
5122 // old build platforms may not support dynamic cpu sets
5123 #ifdef CPU_ALLOC
5124
5125 // To enable easy testing of the dynamic path on different platforms we
5126 // introduce a diagnostic flag: UseCpuAllocPath
5127 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) {
5128 // kernel may use a mask bigger than cpu_set_t
5129 log_trace(os)("active_processor_count: using dynamic path %s"
5130 "- configured processors: %d",
5131 UseCpuAllocPath ? "(forced) " : "",
5132 configured_cpus);
5133 cpus_p = CPU_ALLOC(configured_cpus);
5134 if (cpus_p != NULL) {
5135 cpus_size = CPU_ALLOC_SIZE(configured_cpus);
5136 // zero it just to be safe
5137 CPU_ZERO_S(cpus_size, cpus_p);
5138 }
5139 else {
5140 // failed to allocate so fallback to online cpus
5141 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
5142 log_trace(os)("active_processor_count: "
5143 "CPU_ALLOC failed (%s) - using "
5144 "online processor count: %d",
5145 os::strerror(errno), online_cpus);
5146 return online_cpus;
5147 }
5148 }
5149 else {
5150 log_trace(os)("active_processor_count: using static path - configured processors: %d",
5151 configured_cpus);
5152 }
5153 #else // CPU_ALLOC
5154 // these stubs won't be executed
5155 #define CPU_COUNT_S(size, cpus) -1
5156 #define CPU_FREE(cpus)
5157
5158 log_trace(os)("active_processor_count: only static path available - configured processors: %d",
5159 configured_cpus);
5160 #endif // CPU_ALLOC
5161
5162 // pid 0 means the current thread - which we have to assume represents the process
5163 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) {
5164 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5165 cpu_count = CPU_COUNT_S(cpus_size, cpus_p);
5166 }
5167 else {
5168 cpu_count = CPU_COUNT(cpus_p);
5169 }
5170 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count);
5171 }
5172 else {
5173 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN);
5174 warning("sched_getaffinity failed (%s)- using online processor count (%d) "
5175 "which may exceed available processors", os::strerror(errno), cpu_count);
5176 }
5177
5178 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5179 CPU_FREE(cpus_p);
5180 }
5181
5182 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check");
5183 return cpu_count;
5184 }
5185
5186 // Determine the active processor count from one of
5187 // three different sources:
5188 //
5189 // 1. User option -XX:ActiveProcessorCount
5190 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN)
5191 // 3. extracted from cgroup cpu subsystem (shares and quotas)
5192 //
5193 // Option 1, if specified, will always override.
5194 // If the cgroup subsystem is active and configured, we
5195 // will return the min of the cgroup and option 2 results.
5196 // This is required since tools, such as numactl, that
5197 // alter cpu affinity do not update cgroup subsystem
5198 // cpuset configuration files.
5199 int os::active_processor_count() {
5200 // User has overridden the number of active processors
5201 if (ActiveProcessorCount > 0) {
5202 log_trace(os)("active_processor_count: "
5203 "active processor count set by user : %d",
5204 ActiveProcessorCount);
5205 return ActiveProcessorCount;
5206 }
5207
5208 int active_cpus;
5209 if (OSContainer::is_containerized()) {
5210 active_cpus = OSContainer::active_processor_count();
5211 log_trace(os)("active_processor_count: determined by OSContainer: %d",
5212 active_cpus);
5213 } else {
5214 active_cpus = os::Linux::active_processor_count();
5215 }
5216
5217 return active_cpus;
5218 }
5219
5220 uint os::processor_id() {
5221 const int id = Linux::sched_getcpu();
5222 assert(id >= 0 && id < _processor_count, "Invalid processor id");
5223 return (uint)id;
5224 }
5225
5226 void os::set_native_thread_name(const char *name) {
5227 if (Linux::_pthread_setname_np) {
5228 char buf [16]; // according to glibc manpage, 16 chars incl. '/0'
5229 snprintf(buf, sizeof(buf), "%s", name);
5230 buf[sizeof(buf) - 1] = '\0';
5231 const int rc = Linux::_pthread_setname_np(pthread_self(), buf);
5232 // ERANGE should not happen; all other errors should just be ignored.
5233 assert(rc != ERANGE, "pthread_setname_np failed");
5234 }
5235 }
5236
5237 bool os::distribute_processes(uint length, uint* distribution) {
5238 // Not yet implemented.
5239 return false;
5240 }
5241
5242 bool os::bind_to_processor(uint processor_id) {
5243 // Not yet implemented.
5244 return false;
5245 }
5246
5247 ///
5248
5249 void os::SuspendedThreadTask::internal_do_task() {
5250 if (do_suspend(_thread->osthread())) {
5251 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
5252 do_task(context);
5253 do_resume(_thread->osthread());
5254 }
5255 }
5256
5257 ////////////////////////////////////////////////////////////////////////////////
5258 // debug support
5259
5260 bool os::find(address addr, outputStream* st) {
5261 Dl_info dlinfo;
5262 memset(&dlinfo, 0, sizeof(dlinfo));
5263 if (dladdr(addr, &dlinfo) != 0) {
5264 st->print(PTR_FORMAT ": ", p2i(addr));
5265 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
5266 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname,
5267 p2i(addr) - p2i(dlinfo.dli_saddr));
5268 } else if (dlinfo.dli_fbase != NULL) {
5269 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase));
5270 } else {
5271 st->print("<absolute address>");
5272 }
5273 if (dlinfo.dli_fname != NULL) {
5274 st->print(" in %s", dlinfo.dli_fname);
5275 }
5276 if (dlinfo.dli_fbase != NULL) {
5277 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase));
5278 }
5279 st->cr();
5280
5281 if (Verbose) {
5282 // decode some bytes around the PC
5283 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
5284 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
5285 address lowest = (address) dlinfo.dli_sname;
5286 if (!lowest) lowest = (address) dlinfo.dli_fbase;
5287 if (begin < lowest) begin = lowest;
5288 Dl_info dlinfo2;
5289 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
5290 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
5291 end = (address) dlinfo2.dli_saddr;
5292 }
5293 Disassembler::decode(begin, end, st);
5294 }
5295 return true;
5296 }
5297 return false;
5298 }
5299
5300 ////////////////////////////////////////////////////////////////////////////////
5301 // misc
5302
5303 // This does not do anything on Linux. This is basically a hook for being
5304 // able to use structured exception handling (thread-local exception filters)
5305 // on, e.g., Win32.
5306 void
5307 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
5308 JavaCallArguments* args, Thread* thread) {
5309 f(value, method, args, thread);
5310 }
5311
5312 void os::print_statistics() {
5313 }
5314
5315 bool os::message_box(const char* title, const char* message) {
5316 int i;
5317 fdStream err(defaultStream::error_fd());
5318 for (i = 0; i < 78; i++) err.print_raw("=");
5319 err.cr();
5320 err.print_raw_cr(title);
5321 for (i = 0; i < 78; i++) err.print_raw("-");
5322 err.cr();
5323 err.print_raw_cr(message);
5324 for (i = 0; i < 78; i++) err.print_raw("=");
5325 err.cr();
5326
5327 char buf[16];
5328 // Prevent process from exiting upon "read error" without consuming all CPU
5329 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
5330
5331 return buf[0] == 'y' || buf[0] == 'Y';
5332 }
5333
5334 // Is a (classpath) directory empty?
5335 bool os::dir_is_empty(const char* path) {
5336 DIR *dir = NULL;
5337 struct dirent *ptr;
5338
5339 dir = opendir(path);
5340 if (dir == NULL) return true;
5341
5342 // Scan the directory
5343 bool result = true;
5344 while (result && (ptr = readdir(dir)) != NULL) {
5345 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
5346 result = false;
5347 }
5348 }
5349 closedir(dir);
5350 return result;
5351 }
5352
5353 // This code originates from JDK's sysOpen and open64_w
5354 // from src/solaris/hpi/src/system_md.c
5355
5356 int os::open(const char *path, int oflag, int mode) {
5357 if (strlen(path) > MAX_PATH - 1) {
5358 errno = ENAMETOOLONG;
5359 return -1;
5360 }
5361
5362 // All file descriptors that are opened in the Java process and not
5363 // specifically destined for a subprocess should have the close-on-exec
5364 // flag set. If we don't set it, then careless 3rd party native code
5365 // might fork and exec without closing all appropriate file descriptors
5366 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in
5367 // turn might:
5368 //
5369 // - cause end-of-file to fail to be detected on some file
5370 // descriptors, resulting in mysterious hangs, or
5371 //
5372 // - might cause an fopen in the subprocess to fail on a system
5373 // suffering from bug 1085341.
5374 //
5375 // (Yes, the default setting of the close-on-exec flag is a Unix
5376 // design flaw)
5377 //
5378 // See:
5379 // 1085341: 32-bit stdio routines should support file descriptors >255
5380 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
5381 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
5382 //
5383 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open().
5384 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor
5385 // because it saves a system call and removes a small window where the flag
5386 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored
5387 // and we fall back to using FD_CLOEXEC (see below).
5388 #ifdef O_CLOEXEC
5389 oflag |= O_CLOEXEC;
5390 #endif
5391
5392 int fd = ::open64(path, oflag, mode);
5393 if (fd == -1) return -1;
5394
5395 //If the open succeeded, the file might still be a directory
5396 {
5397 struct stat64 buf64;
5398 int ret = ::fstat64(fd, &buf64);
5399 int st_mode = buf64.st_mode;
5400
5401 if (ret != -1) {
5402 if ((st_mode & S_IFMT) == S_IFDIR) {
5403 errno = EISDIR;
5404 ::close(fd);
5405 return -1;
5406 }
5407 } else {
5408 ::close(fd);
5409 return -1;
5410 }
5411 }
5412
5413 #ifdef FD_CLOEXEC
5414 // Validate that the use of the O_CLOEXEC flag on open above worked.
5415 // With recent kernels, we will perform this check exactly once.
5416 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
5417 if (!O_CLOEXEC_is_known_to_work) {
5418 int flags = ::fcntl(fd, F_GETFD);
5419 if (flags != -1) {
5420 if ((flags & FD_CLOEXEC) != 0)
5421 O_CLOEXEC_is_known_to_work = 1;
5422 else
5423 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
5424 }
5425 }
5426 #endif
5427
5428 return fd;
5429 }
5430
5431
5432 // create binary file, rewriting existing file if required
5433 int os::create_binary_file(const char* path, bool rewrite_existing) {
5434 int oflags = O_WRONLY | O_CREAT;
5435 if (!rewrite_existing) {
5436 oflags |= O_EXCL;
5437 }
5438 return ::open64(path, oflags, S_IREAD | S_IWRITE);
5439 }
5440
5441 // return current position of file pointer
5442 jlong os::current_file_offset(int fd) {
5443 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
5444 }
5445
5446 // move file pointer to the specified offset
5447 jlong os::seek_to_file_offset(int fd, jlong offset) {
5448 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
5449 }
5450
5451 // This code originates from JDK's sysAvailable
5452 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
5453
5454 int os::available(int fd, jlong *bytes) {
5455 jlong cur, end;
5456 int mode;
5457 struct stat64 buf64;
5458
5459 if (::fstat64(fd, &buf64) >= 0) {
5460 mode = buf64.st_mode;
5461 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
5462 int n;
5463 if (::ioctl(fd, FIONREAD, &n) >= 0) {
5464 *bytes = n;
5465 return 1;
5466 }
5467 }
5468 }
5469 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
5470 return 0;
5471 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
5472 return 0;
5473 } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
5474 return 0;
5475 }
5476 *bytes = end - cur;
5477 return 1;
5478 }
5479
5480 // Map a block of memory.
5481 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
5482 char *addr, size_t bytes, bool read_only,
5483 bool allow_exec) {
5484 int prot;
5485 int flags = MAP_PRIVATE;
5486
5487 if (read_only) {
5488 prot = PROT_READ;
5489 } else {
5490 prot = PROT_READ | PROT_WRITE;
5491 }
5492
5493 if (allow_exec) {
5494 prot |= PROT_EXEC;
5495 }
5496
5497 if (addr != NULL) {
5498 flags |= MAP_FIXED;
5499 }
5500
5501 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
5502 fd, file_offset);
5503 if (mapped_address == MAP_FAILED) {
5504 return NULL;
5505 }
5506 return mapped_address;
5507 }
5508
5509
5510 // Remap a block of memory.
5511 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
5512 char *addr, size_t bytes, bool read_only,
5513 bool allow_exec) {
5514 // same as map_memory() on this OS
5515 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
5516 allow_exec);
5517 }
5518
5519
5520 // Unmap a block of memory.
5521 bool os::pd_unmap_memory(char* addr, size_t bytes) {
5522 return munmap(addr, bytes) == 0;
5523 }
5524
5525 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time);
5526
5527 static jlong fast_cpu_time(Thread *thread) {
5528 clockid_t clockid;
5529 int rc = os::Linux::pthread_getcpuclockid(thread->osthread()->pthread_id(),
5530 &clockid);
5531 if (rc == 0) {
5532 return os::Linux::fast_thread_cpu_time(clockid);
5533 } else {
5534 // It's possible to encounter a terminated native thread that failed
5535 // to detach itself from the VM - which should result in ESRCH.
5536 assert_status(rc == ESRCH, rc, "pthread_getcpuclockid failed");
5537 return -1;
5538 }
5539 }
5540
5541 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
5542 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
5543 // of a thread.
5544 //
5545 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
5546 // the fast estimate available on the platform.
5547
5548 jlong os::current_thread_cpu_time() {
5549 if (os::Linux::supports_fast_thread_cpu_time()) {
5550 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5551 } else {
5552 // return user + sys since the cost is the same
5553 return slow_thread_cpu_time(Thread::current(), true /* user + sys */);
5554 }
5555 }
5556
5557 jlong os::thread_cpu_time(Thread* thread) {
5558 // consistent with what current_thread_cpu_time() returns
5559 if (os::Linux::supports_fast_thread_cpu_time()) {
5560 return fast_cpu_time(thread);
5561 } else {
5562 return slow_thread_cpu_time(thread, true /* user + sys */);
5563 }
5564 }
5565
5566 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
5567 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5568 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5569 } else {
5570 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time);
5571 }
5572 }
5573
5574 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5575 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5576 return fast_cpu_time(thread);
5577 } else {
5578 return slow_thread_cpu_time(thread, user_sys_cpu_time);
5579 }
5580 }
5581
5582 // -1 on error.
5583 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5584 pid_t tid = thread->osthread()->thread_id();
5585 char *s;
5586 char stat[2048];
5587 int statlen;
5588 char proc_name[64];
5589 int count;
5590 long sys_time, user_time;
5591 char cdummy;
5592 int idummy;
5593 long ldummy;
5594 FILE *fp;
5595
5596 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid);
5597 fp = fopen(proc_name, "r");
5598 if (fp == NULL) return -1;
5599 statlen = fread(stat, 1, 2047, fp);
5600 stat[statlen] = '\0';
5601 fclose(fp);
5602
5603 // Skip pid and the command string. Note that we could be dealing with
5604 // weird command names, e.g. user could decide to rename java launcher
5605 // to "java 1.4.2 :)", then the stat file would look like
5606 // 1234 (java 1.4.2 :)) R ... ...
5607 // We don't really need to know the command string, just find the last
5608 // occurrence of ")" and then start parsing from there. See bug 4726580.
5609 s = strrchr(stat, ')');
5610 if (s == NULL) return -1;
5611
5612 // Skip blank chars
5613 do { s++; } while (s && isspace(*s));
5614
5615 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu",
5616 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy,
5617 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy,
5618 &user_time, &sys_time);
5619 if (count != 13) return -1;
5620 if (user_sys_cpu_time) {
5621 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
5622 } else {
5623 return (jlong)user_time * (1000000000 / clock_tics_per_sec);
5624 }
5625 }
5626
5627 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5628 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5629 info_ptr->may_skip_backward = false; // elapsed time not wall time
5630 info_ptr->may_skip_forward = false; // elapsed time not wall time
5631 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5632 }
5633
5634 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5635 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5636 info_ptr->may_skip_backward = false; // elapsed time not wall time
5637 info_ptr->may_skip_forward = false; // elapsed time not wall time
5638 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5639 }
5640
5641 bool os::is_thread_cpu_time_supported() {
5642 return true;
5643 }
5644
5645 // System loadavg support. Returns -1 if load average cannot be obtained.
5646 // Linux doesn't yet have a (official) notion of processor sets,
5647 // so just return the system wide load average.
5648 int os::loadavg(double loadavg[], int nelem) {
5649 return ::getloadavg(loadavg, nelem);
5650 }
5651
5652 void os::pause() {
5653 char filename[MAX_PATH];
5654 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
5655 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
5656 } else {
5657 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
5658 }
5659
5660 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
5661 if (fd != -1) {
5662 struct stat buf;
5663 ::close(fd);
5664 while (::stat(filename, &buf) == 0) {
5665 (void)::poll(NULL, 0, 100);
5666 }
5667 } else {
5668 jio_fprintf(stderr,
5669 "Could not open pause file '%s', continuing immediately.\n", filename);
5670 }
5671 }
5672
5673 extern char** environ;
5674
5675 // Run the specified command in a separate process. Return its exit value,
5676 // or -1 on failure (e.g. can't fork a new process).
5677 // Unlike system(), this function can be called from signal handler. It
5678 // doesn't block SIGINT et al.
5679 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
5680 const char * argv[4] = {"sh", "-c", cmd, NULL};
5681
5682 pid_t pid ;
5683
5684 if (use_vfork_if_available) {
5685 pid = vfork();
5686 } else {
5687 pid = fork();
5688 }
5689
5690 if (pid < 0) {
5691 // fork failed
5692 return -1;
5693
5694 } else if (pid == 0) {
5695 // child process
5696
5697 execve("/bin/sh", (char* const*)argv, environ);
5698
5699 // execve failed
5700 _exit(-1);
5701
5702 } else {
5703 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
5704 // care about the actual exit code, for now.
5705
5706 int status;
5707
5708 // Wait for the child process to exit. This returns immediately if
5709 // the child has already exited. */
5710 while (waitpid(pid, &status, 0) < 0) {
5711 switch (errno) {
5712 case ECHILD: return 0;
5713 case EINTR: break;
5714 default: return -1;
5715 }
5716 }
5717
5718 if (WIFEXITED(status)) {
5719 // The child exited normally; get its exit code.
5720 return WEXITSTATUS(status);
5721 } else if (WIFSIGNALED(status)) {
5722 // The child exited because of a signal
5723 // The best value to return is 0x80 + signal number,
5724 // because that is what all Unix shells do, and because
5725 // it allows callers to distinguish between process exit and
5726 // process death by signal.
5727 return 0x80 + WTERMSIG(status);
5728 } else {
5729 // Unknown exit code; pass it through
5730 return status;
5731 }
5732 }
5733 }
5734
5735 // Get the default path to the core file
5736 // Returns the length of the string
5737 int os::get_core_path(char* buffer, size_t bufferSize) {
5738 /*
5739 * Max length of /proc/sys/kernel/core_pattern is 128 characters.
5740 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
5741 */
5742 const int core_pattern_len = 129;
5743 char core_pattern[core_pattern_len] = {0};
5744
5745 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY);
5746 if (core_pattern_file == -1) {
5747 return -1;
5748 }
5749
5750 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len);
5751 ::close(core_pattern_file);
5752 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') {
5753 return -1;
5754 }
5755 if (core_pattern[ret-1] == '\n') {
5756 core_pattern[ret-1] = '\0';
5757 } else {
5758 core_pattern[ret] = '\0';
5759 }
5760
5761 // Replace the %p in the core pattern with the process id. NOTE: we do this
5762 // only if the pattern doesn't start with "|", and we support only one %p in
5763 // the pattern.
5764 char *pid_pos = strstr(core_pattern, "%p");
5765 const char* tail = (pid_pos != NULL) ? (pid_pos + 2) : ""; // skip over the "%p"
5766 int written;
5767
5768 if (core_pattern[0] == '/') {
5769 if (pid_pos != NULL) {
5770 *pid_pos = '\0';
5771 written = jio_snprintf(buffer, bufferSize, "%s%d%s", core_pattern,
5772 current_process_id(), tail);
5773 } else {
5774 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern);
5775 }
5776 } else {
5777 char cwd[PATH_MAX];
5778
5779 const char* p = get_current_directory(cwd, PATH_MAX);
5780 if (p == NULL) {
5781 return -1;
5782 }
5783
5784 if (core_pattern[0] == '|') {
5785 written = jio_snprintf(buffer, bufferSize,
5786 "\"%s\" (or dumping to %s/core.%d)",
5787 &core_pattern[1], p, current_process_id());
5788 } else if (pid_pos != NULL) {
5789 *pid_pos = '\0';
5790 written = jio_snprintf(buffer, bufferSize, "%s/%s%d%s", p, core_pattern,
5791 current_process_id(), tail);
5792 } else {
5793 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern);
5794 }
5795 }
5796
5797 if (written < 0) {
5798 return -1;
5799 }
5800
5801 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) {
5802 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY);
5803
5804 if (core_uses_pid_file != -1) {
5805 char core_uses_pid = 0;
5806 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1);
5807 ::close(core_uses_pid_file);
5808
5809 if (core_uses_pid == '1') {
5810 jio_snprintf(buffer + written, bufferSize - written,
5811 ".%d", current_process_id());
5812 }
5813 }
5814 }
5815
5816 return strlen(buffer);
5817 }
5818
5819 bool os::start_debugging(char *buf, int buflen) {
5820 int len = (int)strlen(buf);
5821 char *p = &buf[len];
5822
5823 jio_snprintf(p, buflen-len,
5824 "\n\n"
5825 "Do you want to debug the problem?\n\n"
5826 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n"
5827 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
5828 "Otherwise, press RETURN to abort...",
5829 os::current_process_id(), os::current_process_id(),
5830 os::current_thread_id(), os::current_thread_id());
5831
5832 bool yes = os::message_box("Unexpected Error", buf);
5833
5834 if (yes) {
5835 // yes, user asked VM to launch debugger
5836 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d",
5837 os::current_process_id(), os::current_process_id());
5838
5839 os::fork_and_exec(buf);
5840 yes = false;
5841 }
5842 return yes;
5843 }
5844
5845
5846 // Java/Compiler thread:
5847 //
5848 // Low memory addresses
5849 // P0 +------------------------+
5850 // | |\ Java thread created by VM does not have glibc
5851 // | glibc guard page | - guard page, attached Java thread usually has
5852 // | |/ 1 glibc guard page.
5853 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
5854 // | |\
5855 // | HotSpot Guard Pages | - red, yellow and reserved pages
5856 // | |/
5857 // +------------------------+ JavaThread::stack_reserved_zone_base()
5858 // | |\
5859 // | Normal Stack | -
5860 // | |/
5861 // P2 +------------------------+ Thread::stack_base()
5862 //
5863 // Non-Java thread:
5864 //
5865 // Low memory addresses
5866 // P0 +------------------------+
5867 // | |\
5868 // | glibc guard page | - usually 1 page
5869 // | |/
5870 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
5871 // | |\
5872 // | Normal Stack | -
5873 // | |/
5874 // P2 +------------------------+ Thread::stack_base()
5875 //
5876 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size
5877 // returned from pthread_attr_getstack().
5878 // ** Due to NPTL implementation error, linux takes the glibc guard page out
5879 // of the stack size given in pthread_attr. We work around this for
5880 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.)
5881 //
5882 #ifndef ZERO
5883 static void current_stack_region(address * bottom, size_t * size) {
5884 if (os::is_primordial_thread()) {
5885 // primordial thread needs special handling because pthread_getattr_np()
5886 // may return bogus value.
5887 *bottom = os::Linux::initial_thread_stack_bottom();
5888 *size = os::Linux::initial_thread_stack_size();
5889 } else {
5890 pthread_attr_t attr;
5891
5892 int rslt = pthread_getattr_np(pthread_self(), &attr);
5893
5894 // JVM needs to know exact stack location, abort if it fails
5895 if (rslt != 0) {
5896 if (rslt == ENOMEM) {
5897 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
5898 } else {
5899 fatal("pthread_getattr_np failed with error = %d", rslt);
5900 }
5901 }
5902
5903 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
5904 fatal("Cannot locate current stack attributes!");
5905 }
5906
5907 // Work around NPTL stack guard error.
5908 size_t guard_size = 0;
5909 rslt = pthread_attr_getguardsize(&attr, &guard_size);
5910 if (rslt != 0) {
5911 fatal("pthread_attr_getguardsize failed with error = %d", rslt);
5912 }
5913 *bottom += guard_size;
5914 *size -= guard_size;
5915
5916 pthread_attr_destroy(&attr);
5917
5918 }
5919 assert(os::current_stack_pointer() >= *bottom &&
5920 os::current_stack_pointer() < *bottom + *size, "just checking");
5921 }
5922
5923 address os::current_stack_base() {
5924 address bottom;
5925 size_t size;
5926 current_stack_region(&bottom, &size);
5927 return (bottom + size);
5928 }
5929
5930 size_t os::current_stack_size() {
5931 // This stack size includes the usable stack and HotSpot guard pages
5932 // (for the threads that have Hotspot guard pages).
5933 address bottom;
5934 size_t size;
5935 current_stack_region(&bottom, &size);
5936 return size;
5937 }
5938 #endif
5939
5940 static inline struct timespec get_mtime(const char* filename) {
5941 struct stat st;
5942 int ret = os::stat(filename, &st);
5943 assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
5944 return st.st_mtim;
5945 }
5946
5947 int os::compare_file_modified_times(const char* file1, const char* file2) {
5948 struct timespec filetime1 = get_mtime(file1);
5949 struct timespec filetime2 = get_mtime(file2);
5950 int diff = filetime1.tv_sec - filetime2.tv_sec;
5951 if (diff == 0) {
5952 return filetime1.tv_nsec - filetime2.tv_nsec;
5953 }
5954 return diff;
5955 }
5956
5957 /////////////// Unit tests ///////////////
5958
5959 #ifndef PRODUCT
5960
5961 #define test_log(...) \
5962 do { \
5963 if (VerboseInternalVMTests) { \
5964 tty->print_cr(__VA_ARGS__); \
5965 tty->flush(); \
5966 } \
5967 } while (false)
5968
5969 class TestReserveMemorySpecial : AllStatic {
5970 public:
5971 static void small_page_write(void* addr, size_t size) {
5972 size_t page_size = os::vm_page_size();
5973
5974 char* end = (char*)addr + size;
5975 for (char* p = (char*)addr; p < end; p += page_size) {
5976 *p = 1;
5977 }
5978 }
5979
5980 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) {
5981 if (!UseHugeTLBFS) {
5982 return;
5983 }
5984
5985 test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size);
5986
5987 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false);
5988
5989 if (addr != NULL) {
5990 small_page_write(addr, size);
5991
5992 os::Linux::release_memory_special_huge_tlbfs(addr, size);
5993 }
5994 }
5995
5996 static void test_reserve_memory_special_huge_tlbfs_only() {
5997 if (!UseHugeTLBFS) {
5998 return;
5999 }
6000
6001 size_t lp = os::large_page_size();
6002
6003 for (size_t size = lp; size <= lp * 10; size += lp) {
6004 test_reserve_memory_special_huge_tlbfs_only(size);
6005 }
6006 }
6007
6008 static void test_reserve_memory_special_huge_tlbfs_mixed() {
6009 size_t lp = os::large_page_size();
6010 size_t ag = os::vm_allocation_granularity();
6011
6012 // sizes to test
6013 const size_t sizes[] = {
6014 lp, lp + ag, lp + lp / 2, lp * 2,
6015 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2,
6016 lp * 10, lp * 10 + lp / 2
6017 };
6018 const int num_sizes = sizeof(sizes) / sizeof(size_t);
6019
6020 // For each size/alignment combination, we test three scenarios:
6021 // 1) with req_addr == NULL
6022 // 2) with a non-null req_addr at which we expect to successfully allocate
6023 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we
6024 // expect the allocation to either fail or to ignore req_addr
6025
6026 // Pre-allocate two areas; they shall be as large as the largest allocation
6027 // and aligned to the largest alignment we will be testing.
6028 const size_t mapping_size = sizes[num_sizes - 1] * 2;
6029 char* const mapping1 = (char*) ::mmap(NULL, mapping_size,
6030 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6031 -1, 0);
6032 assert(mapping1 != MAP_FAILED, "should work");
6033
6034 char* const mapping2 = (char*) ::mmap(NULL, mapping_size,
6035 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6036 -1, 0);
6037 assert(mapping2 != MAP_FAILED, "should work");
6038
6039 // Unmap the first mapping, but leave the second mapping intact: the first
6040 // mapping will serve as a value for a "good" req_addr (case 2). The second
6041 // mapping, still intact, as "bad" req_addr (case 3).
6042 ::munmap(mapping1, mapping_size);
6043
6044 // Case 1
6045 test_log("%s, req_addr NULL:", __FUNCTION__);
6046 test_log("size align result");
6047
6048 for (int i = 0; i < num_sizes; i++) {
6049 const size_t size = sizes[i];
6050 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6051 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false);
6052 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s",
6053 size, alignment, p2i(p), (p != NULL ? "" : "(failed)"));
6054 if (p != NULL) {
6055 assert(is_aligned(p, alignment), "must be");
6056 small_page_write(p, size);
6057 os::Linux::release_memory_special_huge_tlbfs(p, size);
6058 }
6059 }
6060 }
6061
6062 // Case 2
6063 test_log("%s, req_addr non-NULL:", __FUNCTION__);
6064 test_log("size align req_addr result");
6065
6066 for (int i = 0; i < num_sizes; i++) {
6067 const size_t size = sizes[i];
6068 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6069 char* const req_addr = align_up(mapping1, alignment);
6070 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6071 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s",
6072 size, alignment, p2i(req_addr), p2i(p),
6073 ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)")));
6074 if (p != NULL) {
6075 assert(p == req_addr, "must be");
6076 small_page_write(p, size);
6077 os::Linux::release_memory_special_huge_tlbfs(p, size);
6078 }
6079 }
6080 }
6081
6082 // Case 3
6083 test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__);
6084 test_log("size align req_addr result");
6085
6086 for (int i = 0; i < num_sizes; i++) {
6087 const size_t size = sizes[i];
6088 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6089 char* const req_addr = align_up(mapping2, alignment);
6090 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6091 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s",
6092 size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)")));
6093 // as the area around req_addr contains already existing mappings, the API should always
6094 // return NULL (as per contract, it cannot return another address)
6095 assert(p == NULL, "must be");
6096 }
6097 }
6098
6099 ::munmap(mapping2, mapping_size);
6100
6101 }
6102
6103 static void test_reserve_memory_special_huge_tlbfs() {
6104 if (!UseHugeTLBFS) {
6105 return;
6106 }
6107
6108 test_reserve_memory_special_huge_tlbfs_only();
6109 test_reserve_memory_special_huge_tlbfs_mixed();
6110 }
6111
6112 static void test_reserve_memory_special_shm(size_t size, size_t alignment) {
6113 if (!UseSHM) {
6114 return;
6115 }
6116
6117 test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment);
6118
6119 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false);
6120
6121 if (addr != NULL) {
6122 assert(is_aligned(addr, alignment), "Check");
6123 assert(is_aligned(addr, os::large_page_size()), "Check");
6124
6125 small_page_write(addr, size);
6126
6127 os::Linux::release_memory_special_shm(addr, size);
6128 }
6129 }
6130
6131 static void test_reserve_memory_special_shm() {
6132 size_t lp = os::large_page_size();
6133 size_t ag = os::vm_allocation_granularity();
6134
6135 for (size_t size = ag; size < lp * 3; size += ag) {
6136 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6137 test_reserve_memory_special_shm(size, alignment);
6138 }
6139 }
6140 }
6141
6142 static void test() {
6143 test_reserve_memory_special_huge_tlbfs();
6144 test_reserve_memory_special_shm();
6145 }
6146 };
6147
6148 void TestReserveMemorySpecial_test() {
6149 TestReserveMemorySpecial::test();
6150 }
6151
6152 #endif