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::_clock_gettime)(clockid_t, struct timespec *) = NULL;
141 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL;
142 int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL;
143 Mutex* os::Linux::_createThread_lock = NULL;
144 pthread_t os::Linux::_main_thread;
145 int os::Linux::_page_size = -1;
146 bool os::Linux::_supports_fast_thread_cpu_time = false;
147 uint32_t os::Linux::_os_version = 0;
148 const char * os::Linux::_glibc_version = NULL;
149 const char * os::Linux::_libpthread_version = NULL;
150
151 static jlong initial_time_count=0;
152
153 static int clock_tics_per_sec = 100;
154
155 // If the VM might have been created on the primordial thread, we need to resolve the
156 // primordial thread stack bounds and check if the current thread might be the
157 // primordial thread in places. If we know that the primordial thread is never used,
158 // such as when the VM was created by one of the standard java launchers, we can
159 // avoid this
160 static bool suppress_primordial_thread_resolution = false;
161
162 // For diagnostics to print a message once. see run_periodic_checks
163 static sigset_t check_signal_done;
164 static bool check_signals = true;
165
166 // Signal number used to suspend/resume a thread
167
168 // do not use any signal number less than SIGSEGV, see 4355769
169 static int SR_signum = SIGUSR2;
170 sigset_t SR_sigset;
171
172 // utility functions
173
174 static int SR_initialize();
175
176 julong os::available_memory() {
177 return Linux::available_memory();
178 }
179
180 julong os::Linux::available_memory() {
181 // values in struct sysinfo are "unsigned long"
182 struct sysinfo si;
183 julong avail_mem;
184
185 if (OSContainer::is_containerized()) {
186 jlong mem_limit, mem_usage;
187 if ((mem_limit = OSContainer::memory_limit_in_bytes()) < 1) {
188 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
189 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
190 }
191 if (mem_limit > 0 && (mem_usage = OSContainer::memory_usage_in_bytes()) < 1) {
192 log_debug(os, container)("container memory usage failed: " JLONG_FORMAT ", using host value", mem_usage);
193 }
194 if (mem_limit > 0 && mem_usage > 0 ) {
195 avail_mem = mem_limit > mem_usage ? (julong)mem_limit - (julong)mem_usage : 0;
196 log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem);
197 return avail_mem;
198 }
199 }
200
201 sysinfo(&si);
202 avail_mem = (julong)si.freeram * si.mem_unit;
203 log_trace(os)("available memory: " JULONG_FORMAT, avail_mem);
204 return avail_mem;
205 }
206
207 julong os::physical_memory() {
208 jlong phys_mem = 0;
209 if (OSContainer::is_containerized()) {
210 jlong mem_limit;
211 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) {
212 log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit);
213 return mem_limit;
214 }
215 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
216 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
217 }
218
219 phys_mem = Linux::physical_memory();
220 log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem);
221 return phys_mem;
222 }
223
224 // Return true if user is running as root.
225
226 bool os::have_special_privileges() {
227 static bool init = false;
228 static bool privileges = false;
229 if (!init) {
230 privileges = (getuid() != geteuid()) || (getgid() != getegid());
231 init = true;
232 }
233 return privileges;
234 }
235
236
237 #ifndef SYS_gettid
238 // i386: 224, ia64: 1105, amd64: 186, sparc 143
239 #ifdef __ia64__
240 #define SYS_gettid 1105
241 #else
242 #ifdef __i386__
243 #define SYS_gettid 224
244 #else
245 #ifdef __amd64__
246 #define SYS_gettid 186
247 #else
248 #ifdef __sparc__
249 #define SYS_gettid 143
250 #else
251 #error define gettid for the arch
252 #endif
253 #endif
254 #endif
255 #endif
256 #endif
257
258
259 // pid_t gettid()
260 //
261 // Returns the kernel thread id of the currently running thread. Kernel
262 // thread id is used to access /proc.
263 pid_t os::Linux::gettid() {
264 int rslt = syscall(SYS_gettid);
265 assert(rslt != -1, "must be."); // old linuxthreads implementation?
266 return (pid_t)rslt;
267 }
268
269 // Most versions of linux have a bug where the number of processors are
270 // determined by looking at the /proc file system. In a chroot environment,
271 // the system call returns 1. This causes the VM to act as if it is
272 // a single processor and elide locking (see is_MP() call).
273 static bool unsafe_chroot_detected = false;
274 static const char *unstable_chroot_error = "/proc file system not found.\n"
275 "Java may be unstable running multithreaded in a chroot "
276 "environment on Linux when /proc filesystem is not mounted.";
277
278 void os::Linux::initialize_system_info() {
279 set_processor_count(sysconf(_SC_NPROCESSORS_CONF));
280 if (processor_count() == 1) {
281 pid_t pid = os::Linux::gettid();
282 char fname[32];
283 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid);
284 FILE *fp = fopen(fname, "r");
285 if (fp == NULL) {
286 unsafe_chroot_detected = true;
287 } else {
288 fclose(fp);
289 }
290 }
291 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE);
292 assert(processor_count() > 0, "linux error");
293 }
294
295 void os::init_system_properties_values() {
296 // The next steps are taken in the product version:
297 //
298 // Obtain the JAVA_HOME value from the location of libjvm.so.
299 // This library should be located at:
300 // <JAVA_HOME>/lib/{client|server}/libjvm.so.
301 //
302 // If "/jre/lib/" appears at the right place in the path, then we
303 // assume libjvm.so is installed in a JDK and we use this path.
304 //
305 // Otherwise exit with message: "Could not create the Java virtual machine."
306 //
307 // The following extra steps are taken in the debugging version:
308 //
309 // If "/jre/lib/" does NOT appear at the right place in the path
310 // instead of exit check for $JAVA_HOME environment variable.
311 //
312 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
313 // then we append a fake suffix "hotspot/libjvm.so" to this path so
314 // it looks like libjvm.so is installed there
315 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
316 //
317 // Otherwise exit.
318 //
319 // Important note: if the location of libjvm.so changes this
320 // code needs to be changed accordingly.
321
322 // See ld(1):
323 // The linker uses the following search paths to locate required
324 // shared libraries:
325 // 1: ...
326 // ...
327 // 7: The default directories, normally /lib and /usr/lib.
328 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390)
329 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib"
330 #else
331 #define DEFAULT_LIBPATH "/lib:/usr/lib"
332 #endif
333
334 // Base path of extensions installed on the system.
335 #define SYS_EXT_DIR "/usr/java/packages"
336 #define EXTENSIONS_DIR "/lib/ext"
337
338 // Buffer that fits several sprintfs.
339 // Note that the space for the colon and the trailing null are provided
340 // by the nulls included by the sizeof operator.
341 const size_t bufsize =
342 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
343 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
344 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
345
346 // sysclasspath, java_home, dll_dir
347 {
348 char *pslash;
349 os::jvm_path(buf, bufsize);
350
351 // Found the full path to libjvm.so.
352 // Now cut the path to <java_home>/jre if we can.
353 pslash = strrchr(buf, '/');
354 if (pslash != NULL) {
355 *pslash = '\0'; // Get rid of /libjvm.so.
356 }
357 pslash = strrchr(buf, '/');
358 if (pslash != NULL) {
359 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
360 }
361 Arguments::set_dll_dir(buf);
362
363 if (pslash != NULL) {
364 pslash = strrchr(buf, '/');
365 if (pslash != NULL) {
366 *pslash = '\0'; // Get rid of /lib.
367 }
368 }
369 Arguments::set_java_home(buf);
370 if (!set_boot_path('/', ':')) {
371 vm_exit_during_initialization("Failed setting boot class path.", NULL);
372 }
373 }
374
375 // Where to look for native libraries.
376 //
377 // Note: Due to a legacy implementation, most of the library path
378 // is set in the launcher. This was to accomodate linking restrictions
379 // on legacy Linux implementations (which are no longer supported).
380 // Eventually, all the library path setting will be done here.
381 //
382 // However, to prevent the proliferation of improperly built native
383 // libraries, the new path component /usr/java/packages is added here.
384 // Eventually, all the library path setting will be done here.
385 {
386 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
387 // should always exist (until the legacy problem cited above is
388 // addressed).
389 const char *v = ::getenv("LD_LIBRARY_PATH");
390 const char *v_colon = ":";
391 if (v == NULL) { v = ""; v_colon = ""; }
392 // That's +1 for the colon and +1 for the trailing '\0'.
393 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
394 strlen(v) + 1 +
395 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1,
396 mtInternal);
397 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon);
398 Arguments::set_library_path(ld_library_path);
399 FREE_C_HEAP_ARRAY(char, ld_library_path);
400 }
401
402 // Extensions directories.
403 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
404 Arguments::set_ext_dirs(buf);
405
406 FREE_C_HEAP_ARRAY(char, buf);
407
408 #undef DEFAULT_LIBPATH
409 #undef SYS_EXT_DIR
410 #undef EXTENSIONS_DIR
411 }
412
413 ////////////////////////////////////////////////////////////////////////////////
414 // breakpoint support
415
416 void os::breakpoint() {
417 BREAKPOINT;
418 }
419
420 extern "C" void breakpoint() {
421 // use debugger to set breakpoint here
422 }
423
424 ////////////////////////////////////////////////////////////////////////////////
425 // signal support
426
427 debug_only(static bool signal_sets_initialized = false);
428 static sigset_t unblocked_sigs, vm_sigs;
429
430 void os::Linux::signal_sets_init() {
431 // Should also have an assertion stating we are still single-threaded.
432 assert(!signal_sets_initialized, "Already initialized");
433 // Fill in signals that are necessarily unblocked for all threads in
434 // the VM. Currently, we unblock the following signals:
435 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
436 // by -Xrs (=ReduceSignalUsage));
437 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
438 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
439 // the dispositions or masks wrt these signals.
440 // Programs embedding the VM that want to use the above signals for their
441 // own purposes must, at this time, use the "-Xrs" option to prevent
442 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
443 // (See bug 4345157, and other related bugs).
444 // In reality, though, unblocking these signals is really a nop, since
445 // these signals are not blocked by default.
446 sigemptyset(&unblocked_sigs);
447 sigaddset(&unblocked_sigs, SIGILL);
448 sigaddset(&unblocked_sigs, SIGSEGV);
449 sigaddset(&unblocked_sigs, SIGBUS);
450 sigaddset(&unblocked_sigs, SIGFPE);
451 #if defined(PPC64)
452 sigaddset(&unblocked_sigs, SIGTRAP);
453 #endif
454 sigaddset(&unblocked_sigs, SR_signum);
455
456 if (!ReduceSignalUsage) {
457 if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
458 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
459 }
460 if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
461 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
462 }
463 if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
464 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
465 }
466 }
467 // Fill in signals that are blocked by all but the VM thread.
468 sigemptyset(&vm_sigs);
469 if (!ReduceSignalUsage) {
470 sigaddset(&vm_sigs, BREAK_SIGNAL);
471 }
472 debug_only(signal_sets_initialized = true);
473
474 }
475
476 // These are signals that are unblocked while a thread is running Java.
477 // (For some reason, they get blocked by default.)
478 sigset_t* os::Linux::unblocked_signals() {
479 assert(signal_sets_initialized, "Not initialized");
480 return &unblocked_sigs;
481 }
482
483 // These are the signals that are blocked while a (non-VM) thread is
484 // running Java. Only the VM thread handles these signals.
485 sigset_t* os::Linux::vm_signals() {
486 assert(signal_sets_initialized, "Not initialized");
487 return &vm_sigs;
488 }
489
490 void os::Linux::hotspot_sigmask(Thread* thread) {
491
492 //Save caller's signal mask before setting VM signal mask
493 sigset_t caller_sigmask;
494 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
495
496 OSThread* osthread = thread->osthread();
497 osthread->set_caller_sigmask(caller_sigmask);
498
499 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL);
500
501 if (!ReduceSignalUsage) {
502 if (thread->is_VM_thread()) {
503 // Only the VM thread handles BREAK_SIGNAL ...
504 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
505 } else {
506 // ... all other threads block BREAK_SIGNAL
507 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
508 }
509 }
510 }
511
512 //////////////////////////////////////////////////////////////////////////////
513 // detecting pthread library
514
515 void os::Linux::libpthread_init() {
516 // Save glibc and pthread version strings.
517 #if !defined(_CS_GNU_LIBC_VERSION) || \
518 !defined(_CS_GNU_LIBPTHREAD_VERSION)
519 #error "glibc too old (< 2.3.2)"
520 #endif
521
522 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0);
523 assert(n > 0, "cannot retrieve glibc version");
524 char *str = (char *)malloc(n, mtInternal);
525 confstr(_CS_GNU_LIBC_VERSION, str, n);
526 os::Linux::set_glibc_version(str);
527
528 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
529 assert(n > 0, "cannot retrieve pthread version");
530 str = (char *)malloc(n, mtInternal);
531 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n);
532 os::Linux::set_libpthread_version(str);
533 }
534
535 /////////////////////////////////////////////////////////////////////////////
536 // thread stack expansion
537
538 // os::Linux::manually_expand_stack() takes care of expanding the thread
539 // stack. Note that this is normally not needed: pthread stacks allocate
540 // thread stack using mmap() without MAP_NORESERVE, so the stack is already
541 // committed. Therefore it is not necessary to expand the stack manually.
542 //
543 // Manually expanding the stack was historically needed on LinuxThreads
544 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays
545 // it is kept to deal with very rare corner cases:
546 //
547 // For one, user may run the VM on an own implementation of threads
548 // whose stacks are - like the old LinuxThreads - implemented using
549 // mmap(MAP_GROWSDOWN).
550 //
551 // Also, this coding may be needed if the VM is running on the primordial
552 // thread. Normally we avoid running on the primordial thread; however,
553 // user may still invoke the VM on the primordial thread.
554 //
555 // The following historical comment describes the details about running
556 // on a thread stack allocated with mmap(MAP_GROWSDOWN):
557
558
559 // Force Linux kernel to expand current thread stack. If "bottom" is close
560 // to the stack guard, caller should block all signals.
561 //
562 // MAP_GROWSDOWN:
563 // A special mmap() flag that is used to implement thread stacks. It tells
564 // kernel that the memory region should extend downwards when needed. This
565 // allows early versions of LinuxThreads to only mmap the first few pages
566 // when creating a new thread. Linux kernel will automatically expand thread
567 // stack as needed (on page faults).
568 //
569 // However, because the memory region of a MAP_GROWSDOWN stack can grow on
570 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN
571 // region, it's hard to tell if the fault is due to a legitimate stack
572 // access or because of reading/writing non-exist memory (e.g. buffer
573 // overrun). As a rule, if the fault happens below current stack pointer,
574 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the
575 // application (see Linux kernel fault.c).
576 //
577 // This Linux feature can cause SIGSEGV when VM bangs thread stack for
578 // stack overflow detection.
579 //
580 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do
581 // not use MAP_GROWSDOWN.
582 //
583 // To get around the problem and allow stack banging on Linux, we need to
584 // manually expand thread stack after receiving the SIGSEGV.
585 //
586 // There are two ways to expand thread stack to address "bottom", we used
587 // both of them in JVM before 1.5:
588 // 1. adjust stack pointer first so that it is below "bottom", and then
589 // touch "bottom"
590 // 2. mmap() the page in question
591 //
592 // Now alternate signal stack is gone, it's harder to use 2. For instance,
593 // if current sp is already near the lower end of page 101, and we need to
594 // call mmap() to map page 100, it is possible that part of the mmap() frame
595 // will be placed in page 100. When page 100 is mapped, it is zero-filled.
596 // That will destroy the mmap() frame and cause VM to crash.
597 //
598 // The following code works by adjusting sp first, then accessing the "bottom"
599 // page to force a page fault. Linux kernel will then automatically expand the
600 // stack mapping.
601 //
602 // _expand_stack_to() assumes its frame size is less than page size, which
603 // should always be true if the function is not inlined.
604
605 static void NOINLINE _expand_stack_to(address bottom) {
606 address sp;
607 size_t size;
608 volatile char *p;
609
610 // Adjust bottom to point to the largest address within the same page, it
611 // gives us a one-page buffer if alloca() allocates slightly more memory.
612 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size());
613 bottom += os::Linux::page_size() - 1;
614
615 // sp might be slightly above current stack pointer; if that's the case, we
616 // will alloca() a little more space than necessary, which is OK. Don't use
617 // os::current_stack_pointer(), as its result can be slightly below current
618 // stack pointer, causing us to not alloca enough to reach "bottom".
619 sp = (address)&sp;
620
621 if (sp > bottom) {
622 size = sp - bottom;
623 p = (volatile char *)alloca(size);
624 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?");
625 p[0] = '\0';
626 }
627 }
628
629 void os::Linux::expand_stack_to(address bottom) {
630 _expand_stack_to(bottom);
631 }
632
633 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) {
634 assert(t!=NULL, "just checking");
635 assert(t->osthread()->expanding_stack(), "expand should be set");
636 assert(t->stack_base() != NULL, "stack_base was not initialized");
637
638 if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) {
639 sigset_t mask_all, old_sigset;
640 sigfillset(&mask_all);
641 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset);
642 _expand_stack_to(addr);
643 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL);
644 return true;
645 }
646 return false;
647 }
648
649 //////////////////////////////////////////////////////////////////////////////
650 // create new thread
651
652 // Thread start routine for all newly created threads
653 static void *thread_native_entry(Thread *thread) {
654 // Try to randomize the cache line index of hot stack frames.
655 // This helps when threads of the same stack traces evict each other's
656 // cache lines. The threads can be either from the same JVM instance, or
657 // from different JVM instances. The benefit is especially true for
658 // processors with hyperthreading technology.
659 static int counter = 0;
660 int pid = os::current_process_id();
661 alloca(((pid ^ counter++) & 7) * 128);
662
663 thread->initialize_thread_current();
664
665 OSThread* osthread = thread->osthread();
666 Monitor* sync = osthread->startThread_lock();
667
668 osthread->set_thread_id(os::current_thread_id());
669
670 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
671 os::current_thread_id(), (uintx) pthread_self());
672
673 if (UseNUMA) {
674 int lgrp_id = os::numa_get_group_id();
675 if (lgrp_id != -1) {
676 thread->set_lgrp_id(lgrp_id);
677 }
678 }
679 // initialize signal mask for this thread
680 os::Linux::hotspot_sigmask(thread);
681
682 // initialize floating point control register
683 os::Linux::init_thread_fpu_state();
684
685 // handshaking with parent thread
686 {
687 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
688
689 // notify parent thread
690 osthread->set_state(INITIALIZED);
691 sync->notify_all();
692
693 // wait until os::start_thread()
694 while (osthread->get_state() == INITIALIZED) {
695 sync->wait(Mutex::_no_safepoint_check_flag);
696 }
697 }
698
699 // call one more level start routine
700 thread->run();
701
702 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
703 os::current_thread_id(), (uintx) pthread_self());
704
705 // If a thread has not deleted itself ("delete this") as part of its
706 // termination sequence, we have to ensure thread-local-storage is
707 // cleared before we actually terminate. No threads should ever be
708 // deleted asynchronously with respect to their termination.
709 if (Thread::current_or_null_safe() != NULL) {
710 assert(Thread::current_or_null_safe() == thread, "current thread is wrong");
711 thread->clear_thread_current();
712 }
713
714 return 0;
715 }
716
717 bool os::create_thread(Thread* thread, ThreadType thr_type,
718 size_t req_stack_size) {
719 assert(thread->osthread() == NULL, "caller responsible");
720
721 // Allocate the OSThread object
722 OSThread* osthread = new OSThread(NULL, NULL);
723 if (osthread == NULL) {
724 return false;
725 }
726
727 // set the correct thread state
728 osthread->set_thread_type(thr_type);
729
730 // Initial state is ALLOCATED but not INITIALIZED
731 osthread->set_state(ALLOCATED);
732
733 thread->set_osthread(osthread);
734
735 // init thread attributes
736 pthread_attr_t attr;
737 pthread_attr_init(&attr);
738 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
739
740 // Calculate stack size if it's not specified by caller.
741 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
742 // In the Linux NPTL pthread implementation the guard size mechanism
743 // is not implemented properly. The posix standard requires adding
744 // the size of the guard pages to the stack size, instead Linux
745 // takes the space out of 'stacksize'. Thus we adapt the requested
746 // stack_size by the size of the guard pages to mimick proper
747 // behaviour. However, be careful not to end up with a size
748 // of zero due to overflow. Don't add the guard page in that case.
749 size_t guard_size = os::Linux::default_guard_size(thr_type);
750 if (stack_size <= SIZE_MAX - guard_size) {
751 stack_size += guard_size;
752 }
753 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned");
754
755 int status = pthread_attr_setstacksize(&attr, stack_size);
756 assert_status(status == 0, status, "pthread_attr_setstacksize");
757
758 // Configure glibc guard page.
759 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type));
760
761 ThreadState state;
762
763 {
764 pthread_t tid;
765 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
766
767 char buf[64];
768 if (ret == 0) {
769 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
770 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
771 } else {
772 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
773 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
774 }
775
776 pthread_attr_destroy(&attr);
777
778 if (ret != 0) {
779 // Need to clean up stuff we've allocated so far
780 thread->set_osthread(NULL);
781 delete osthread;
782 return false;
783 }
784
785 // Store pthread info into the OSThread
786 osthread->set_pthread_id(tid);
787
788 // Wait until child thread is either initialized or aborted
789 {
790 Monitor* sync_with_child = osthread->startThread_lock();
791 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
792 while ((state = osthread->get_state()) == ALLOCATED) {
793 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
794 }
795 }
796 }
797
798 // Aborted due to thread limit being reached
799 if (state == ZOMBIE) {
800 thread->set_osthread(NULL);
801 delete osthread;
802 return false;
803 }
804
805 // The thread is returned suspended (in state INITIALIZED),
806 // and is started higher up in the call chain
807 assert(state == INITIALIZED, "race condition");
808 return true;
809 }
810
811 /////////////////////////////////////////////////////////////////////////////
812 // attach existing thread
813
814 // bootstrap the main thread
815 bool os::create_main_thread(JavaThread* thread) {
816 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread");
817 return create_attached_thread(thread);
818 }
819
820 bool os::create_attached_thread(JavaThread* thread) {
821 #ifdef ASSERT
822 thread->verify_not_published();
823 #endif
824
825 // Allocate the OSThread object
826 OSThread* osthread = new OSThread(NULL, NULL);
827
828 if (osthread == NULL) {
829 return false;
830 }
831
832 // Store pthread info into the OSThread
833 osthread->set_thread_id(os::Linux::gettid());
834 osthread->set_pthread_id(::pthread_self());
835
836 // initialize floating point control register
837 os::Linux::init_thread_fpu_state();
838
839 // Initial thread state is RUNNABLE
840 osthread->set_state(RUNNABLE);
841
842 thread->set_osthread(osthread);
843
844 if (UseNUMA) {
845 int lgrp_id = os::numa_get_group_id();
846 if (lgrp_id != -1) {
847 thread->set_lgrp_id(lgrp_id);
848 }
849 }
850
851 if (os::is_primordial_thread()) {
852 // If current thread is primordial thread, its stack is mapped on demand,
853 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map
854 // the entire stack region to avoid SEGV in stack banging.
855 // It is also useful to get around the heap-stack-gap problem on SuSE
856 // kernel (see 4821821 for details). We first expand stack to the top
857 // of yellow zone, then enable stack yellow zone (order is significant,
858 // enabling yellow zone first will crash JVM on SuSE Linux), so there
859 // is no gap between the last two virtual memory regions.
860
861 JavaThread *jt = (JavaThread *)thread;
862 address addr = jt->stack_reserved_zone_base();
863 assert(addr != NULL, "initialization problem?");
864 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled");
865
866 osthread->set_expanding_stack();
867 os::Linux::manually_expand_stack(jt, addr);
868 osthread->clear_expanding_stack();
869 }
870
871 // initialize signal mask for this thread
872 // and save the caller's signal mask
873 os::Linux::hotspot_sigmask(thread);
874
875 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
876 os::current_thread_id(), (uintx) pthread_self());
877
878 return true;
879 }
880
881 void os::pd_start_thread(Thread* thread) {
882 OSThread * osthread = thread->osthread();
883 assert(osthread->get_state() != INITIALIZED, "just checking");
884 Monitor* sync_with_child = osthread->startThread_lock();
885 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
886 sync_with_child->notify();
887 }
888
889 // Free Linux resources related to the OSThread
890 void os::free_thread(OSThread* osthread) {
891 assert(osthread != NULL, "osthread not set");
892
893 // We are told to free resources of the argument thread,
894 // but we can only really operate on the current thread.
895 assert(Thread::current()->osthread() == osthread,
896 "os::free_thread but not current thread");
897
898 #ifdef ASSERT
899 sigset_t current;
900 sigemptyset(¤t);
901 pthread_sigmask(SIG_SETMASK, NULL, ¤t);
902 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!");
903 #endif
904
905 // Restore caller's signal mask
906 sigset_t sigmask = osthread->caller_sigmask();
907 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
908
909 delete osthread;
910 }
911
912 //////////////////////////////////////////////////////////////////////////////
913 // primordial thread
914
915 // Check if current thread is the primordial thread, similar to Solaris thr_main.
916 bool os::is_primordial_thread(void) {
917 if (suppress_primordial_thread_resolution) {
918 return false;
919 }
920 char dummy;
921 // If called before init complete, thread stack bottom will be null.
922 // Can be called if fatal error occurs before initialization.
923 if (os::Linux::initial_thread_stack_bottom() == NULL) return false;
924 assert(os::Linux::initial_thread_stack_bottom() != NULL &&
925 os::Linux::initial_thread_stack_size() != 0,
926 "os::init did not locate primordial thread's stack region");
927 if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() &&
928 (address)&dummy < os::Linux::initial_thread_stack_bottom() +
929 os::Linux::initial_thread_stack_size()) {
930 return true;
931 } else {
932 return false;
933 }
934 }
935
936 // Find the virtual memory area that contains addr
937 static bool find_vma(address addr, address* vma_low, address* vma_high) {
938 FILE *fp = fopen("/proc/self/maps", "r");
939 if (fp) {
940 address low, high;
941 while (!feof(fp)) {
942 if (fscanf(fp, "%p-%p", &low, &high) == 2) {
943 if (low <= addr && addr < high) {
944 if (vma_low) *vma_low = low;
945 if (vma_high) *vma_high = high;
946 fclose(fp);
947 return true;
948 }
949 }
950 for (;;) {
951 int ch = fgetc(fp);
952 if (ch == EOF || ch == (int)'\n') break;
953 }
954 }
955 fclose(fp);
956 }
957 return false;
958 }
959
960 // Locate primordial thread stack. This special handling of primordial thread stack
961 // is needed because pthread_getattr_np() on most (all?) Linux distros returns
962 // bogus value for the primordial process thread. While the launcher has created
963 // the VM in a new thread since JDK 6, we still have to allow for the use of the
964 // JNI invocation API from a primordial thread.
965 void os::Linux::capture_initial_stack(size_t max_size) {
966
967 // max_size is either 0 (which means accept OS default for thread stacks) or
968 // a user-specified value known to be at least the minimum needed. If we
969 // are actually on the primordial thread we can make it appear that we have a
970 // smaller max_size stack by inserting the guard pages at that location. But we
971 // cannot do anything to emulate a larger stack than what has been provided by
972 // the OS or threading library. In fact if we try to use a stack greater than
973 // what is set by rlimit then we will crash the hosting process.
974
975 // Maximum stack size is the easy part, get it from RLIMIT_STACK.
976 // If this is "unlimited" then it will be a huge value.
977 struct rlimit rlim;
978 getrlimit(RLIMIT_STACK, &rlim);
979 size_t stack_size = rlim.rlim_cur;
980
981 // 6308388: a bug in ld.so will relocate its own .data section to the
982 // lower end of primordial stack; reduce ulimit -s value a little bit
983 // so we won't install guard page on ld.so's data section.
984 // But ensure we don't underflow the stack size - allow 1 page spare
985 if (stack_size >= (size_t)(3 * page_size())) {
986 stack_size -= 2 * page_size();
987 }
988
989 // Try to figure out where the stack base (top) is. This is harder.
990 //
991 // When an application is started, glibc saves the initial stack pointer in
992 // a global variable "__libc_stack_end", which is then used by system
993 // libraries. __libc_stack_end should be pretty close to stack top. The
994 // variable is available since the very early days. However, because it is
995 // a private interface, it could disappear in the future.
996 //
997 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar
998 // to __libc_stack_end, it is very close to stack top, but isn't the real
999 // stack top. Note that /proc may not exist if VM is running as a chroot
1000 // program, so reading /proc/<pid>/stat could fail. Also the contents of
1001 // /proc/<pid>/stat could change in the future (though unlikely).
1002 //
1003 // We try __libc_stack_end first. If that doesn't work, look for
1004 // /proc/<pid>/stat. If neither of them works, we use current stack pointer
1005 // as a hint, which should work well in most cases.
1006
1007 uintptr_t stack_start;
1008
1009 // try __libc_stack_end first
1010 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end");
1011 if (p && *p) {
1012 stack_start = *p;
1013 } else {
1014 // see if we can get the start_stack field from /proc/self/stat
1015 FILE *fp;
1016 int pid;
1017 char state;
1018 int ppid;
1019 int pgrp;
1020 int session;
1021 int nr;
1022 int tpgrp;
1023 unsigned long flags;
1024 unsigned long minflt;
1025 unsigned long cminflt;
1026 unsigned long majflt;
1027 unsigned long cmajflt;
1028 unsigned long utime;
1029 unsigned long stime;
1030 long cutime;
1031 long cstime;
1032 long prio;
1033 long nice;
1034 long junk;
1035 long it_real;
1036 uintptr_t start;
1037 uintptr_t vsize;
1038 intptr_t rss;
1039 uintptr_t rsslim;
1040 uintptr_t scodes;
1041 uintptr_t ecode;
1042 int i;
1043
1044 // Figure what the primordial thread stack base is. Code is inspired
1045 // by email from Hans Boehm. /proc/self/stat begins with current pid,
1046 // followed by command name surrounded by parentheses, state, etc.
1047 char stat[2048];
1048 int statlen;
1049
1050 fp = fopen("/proc/self/stat", "r");
1051 if (fp) {
1052 statlen = fread(stat, 1, 2047, fp);
1053 stat[statlen] = '\0';
1054 fclose(fp);
1055
1056 // Skip pid and the command string. Note that we could be dealing with
1057 // weird command names, e.g. user could decide to rename java launcher
1058 // to "java 1.4.2 :)", then the stat file would look like
1059 // 1234 (java 1.4.2 :)) R ... ...
1060 // We don't really need to know the command string, just find the last
1061 // occurrence of ")" and then start parsing from there. See bug 4726580.
1062 char * s = strrchr(stat, ')');
1063
1064 i = 0;
1065 if (s) {
1066 // Skip blank chars
1067 do { s++; } while (s && isspace(*s));
1068
1069 #define _UFM UINTX_FORMAT
1070 #define _DFM INTX_FORMAT
1071
1072 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2
1073 // 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8
1074 i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM,
1075 &state, // 3 %c
1076 &ppid, // 4 %d
1077 &pgrp, // 5 %d
1078 &session, // 6 %d
1079 &nr, // 7 %d
1080 &tpgrp, // 8 %d
1081 &flags, // 9 %lu
1082 &minflt, // 10 %lu
1083 &cminflt, // 11 %lu
1084 &majflt, // 12 %lu
1085 &cmajflt, // 13 %lu
1086 &utime, // 14 %lu
1087 &stime, // 15 %lu
1088 &cutime, // 16 %ld
1089 &cstime, // 17 %ld
1090 &prio, // 18 %ld
1091 &nice, // 19 %ld
1092 &junk, // 20 %ld
1093 &it_real, // 21 %ld
1094 &start, // 22 UINTX_FORMAT
1095 &vsize, // 23 UINTX_FORMAT
1096 &rss, // 24 INTX_FORMAT
1097 &rsslim, // 25 UINTX_FORMAT
1098 &scodes, // 26 UINTX_FORMAT
1099 &ecode, // 27 UINTX_FORMAT
1100 &stack_start); // 28 UINTX_FORMAT
1101 }
1102
1103 #undef _UFM
1104 #undef _DFM
1105
1106 if (i != 28 - 2) {
1107 assert(false, "Bad conversion from /proc/self/stat");
1108 // product mode - assume we are the primordial thread, good luck in the
1109 // embedded case.
1110 warning("Can't detect primordial thread stack location - bad conversion");
1111 stack_start = (uintptr_t) &rlim;
1112 }
1113 } else {
1114 // For some reason we can't open /proc/self/stat (for example, running on
1115 // FreeBSD with a Linux emulator, or inside chroot), this should work for
1116 // most cases, so don't abort:
1117 warning("Can't detect primordial thread stack location - no /proc/self/stat");
1118 stack_start = (uintptr_t) &rlim;
1119 }
1120 }
1121
1122 // Now we have a pointer (stack_start) very close to the stack top, the
1123 // next thing to do is to figure out the exact location of stack top. We
1124 // can find out the virtual memory area that contains stack_start by
1125 // reading /proc/self/maps, it should be the last vma in /proc/self/maps,
1126 // and its upper limit is the real stack top. (again, this would fail if
1127 // running inside chroot, because /proc may not exist.)
1128
1129 uintptr_t stack_top;
1130 address low, high;
1131 if (find_vma((address)stack_start, &low, &high)) {
1132 // success, "high" is the true stack top. (ignore "low", because initial
1133 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.)
1134 stack_top = (uintptr_t)high;
1135 } else {
1136 // failed, likely because /proc/self/maps does not exist
1137 warning("Can't detect primordial thread stack location - find_vma failed");
1138 // best effort: stack_start is normally within a few pages below the real
1139 // stack top, use it as stack top, and reduce stack size so we won't put
1140 // guard page outside stack.
1141 stack_top = stack_start;
1142 stack_size -= 16 * page_size();
1143 }
1144
1145 // stack_top could be partially down the page so align it
1146 stack_top = align_up(stack_top, page_size());
1147
1148 // Allowed stack value is minimum of max_size and what we derived from rlimit
1149 if (max_size > 0) {
1150 _initial_thread_stack_size = MIN2(max_size, stack_size);
1151 } else {
1152 // Accept the rlimit max, but if stack is unlimited then it will be huge, so
1153 // clamp it at 8MB as we do on Solaris
1154 _initial_thread_stack_size = MIN2(stack_size, 8*M);
1155 }
1156 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size());
1157 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size;
1158
1159 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!");
1160
1161 if (log_is_enabled(Info, os, thread)) {
1162 // See if we seem to be on primordial process thread
1163 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) &&
1164 uintptr_t(&rlim) < stack_top;
1165
1166 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: "
1167 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT,
1168 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K,
1169 stack_top, intptr_t(_initial_thread_stack_bottom));
1170 }
1171 }
1172
1173 ////////////////////////////////////////////////////////////////////////////////
1174 // time support
1175
1176 // Time since start-up in seconds to a fine granularity.
1177 // Used by VMSelfDestructTimer and the MemProfiler.
1178 double os::elapsedTime() {
1179
1180 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
1181 }
1182
1183 jlong os::elapsed_counter() {
1184 return javaTimeNanos() - initial_time_count;
1185 }
1186
1187 jlong os::elapsed_frequency() {
1188 return NANOSECS_PER_SEC; // nanosecond resolution
1189 }
1190
1191 bool os::supports_vtime() { return true; }
1192 bool os::enable_vtime() { return false; }
1193 bool os::vtime_enabled() { return false; }
1194
1195 double os::elapsedVTime() {
1196 struct rusage usage;
1197 int retval = getrusage(RUSAGE_THREAD, &usage);
1198 if (retval == 0) {
1199 return (double) (usage.ru_utime.tv_sec + usage.ru_stime.tv_sec) + (double) (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000 * 1000);
1200 } else {
1201 // better than nothing, but not much
1202 return elapsedTime();
1203 }
1204 }
1205
1206 jlong os::javaTimeMillis() {
1207 timeval time;
1208 int status = gettimeofday(&time, NULL);
1209 assert(status != -1, "linux error");
1210 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
1211 }
1212
1213 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
1214 timeval time;
1215 int status = gettimeofday(&time, NULL);
1216 assert(status != -1, "linux error");
1217 seconds = jlong(time.tv_sec);
1218 nanos = jlong(time.tv_usec) * 1000;
1219 }
1220
1221
1222 #ifndef CLOCK_MONOTONIC
1223 #define CLOCK_MONOTONIC (1)
1224 #endif
1225
1226 void os::Linux::clock_init() {
1227 // we do dlopen's in this particular order due to bug in linux
1228 // dynamical loader (see 6348968) leading to crash on exit
1229 void* handle = dlopen("librt.so.1", RTLD_LAZY);
1230 if (handle == NULL) {
1231 handle = dlopen("librt.so", RTLD_LAZY);
1232 }
1233
1234 if (handle) {
1235 int (*clock_getres_func)(clockid_t, struct timespec*) =
1236 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1237 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1238 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1239 if (clock_getres_func && clock_gettime_func) {
1240 // See if monotonic clock is supported by the kernel. Note that some
1241 // early implementations simply return kernel jiffies (updated every
1242 // 1/100 or 1/1000 second). It would be bad to use such a low res clock
1243 // for nano time (though the monotonic property is still nice to have).
1244 // It's fixed in newer kernels, however clock_getres() still returns
1245 // 1/HZ. We check if clock_getres() works, but will ignore its reported
1246 // resolution for now. Hopefully as people move to new kernels, this
1247 // won't be a problem.
1248 struct timespec res;
1249 struct timespec tp;
1250 if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 &&
1251 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1252 // yes, monotonic clock is supported
1253 _clock_gettime = clock_gettime_func;
1254 return;
1255 } else {
1256 // close librt if there is no monotonic clock
1257 dlclose(handle);
1258 }
1259 }
1260 }
1261 warning("No monotonic clock was available - timed services may " \
1262 "be adversely affected if the time-of-day clock changes");
1263 }
1264
1265 #ifndef SYS_clock_getres
1266 #if defined(X86) || defined(PPC64) || defined(S390)
1267 #define SYS_clock_getres AMD64_ONLY(229) IA32_ONLY(266) PPC64_ONLY(247) S390_ONLY(261)
1268 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y)
1269 #else
1270 #warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time"
1271 #define sys_clock_getres(x,y) -1
1272 #endif
1273 #else
1274 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y)
1275 #endif
1276
1277 void os::Linux::fast_thread_clock_init() {
1278 if (!UseLinuxPosixThreadCPUClocks) {
1279 return;
1280 }
1281 clockid_t clockid;
1282 struct timespec tp;
1283 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) =
1284 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid");
1285
1286 // Switch to using fast clocks for thread cpu time if
1287 // the sys_clock_getres() returns 0 error code.
1288 // Note, that some kernels may support the current thread
1289 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks
1290 // returned by the pthread_getcpuclockid().
1291 // If the fast Posix clocks are supported then the sys_clock_getres()
1292 // must return at least tp.tv_sec == 0 which means a resolution
1293 // better than 1 sec. This is extra check for reliability.
1294
1295 if (pthread_getcpuclockid_func &&
1296 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 &&
1297 sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) {
1298 _supports_fast_thread_cpu_time = true;
1299 _pthread_getcpuclockid = pthread_getcpuclockid_func;
1300 }
1301 }
1302
1303 jlong os::javaTimeNanos() {
1304 if (os::supports_monotonic_clock()) {
1305 struct timespec tp;
1306 int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp);
1307 assert(status == 0, "gettime error");
1308 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1309 return result;
1310 } else {
1311 timeval time;
1312 int status = gettimeofday(&time, NULL);
1313 assert(status != -1, "linux error");
1314 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1315 return 1000 * usecs;
1316 }
1317 }
1318
1319 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1320 if (os::supports_monotonic_clock()) {
1321 info_ptr->max_value = ALL_64_BITS;
1322
1323 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1324 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1325 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1326 } else {
1327 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1328 info_ptr->max_value = ALL_64_BITS;
1329
1330 // gettimeofday is a real time clock so it skips
1331 info_ptr->may_skip_backward = true;
1332 info_ptr->may_skip_forward = true;
1333 }
1334
1335 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1336 }
1337
1338 // Return the real, user, and system times in seconds from an
1339 // arbitrary fixed point in the past.
1340 bool os::getTimesSecs(double* process_real_time,
1341 double* process_user_time,
1342 double* process_system_time) {
1343 struct tms ticks;
1344 clock_t real_ticks = times(&ticks);
1345
1346 if (real_ticks == (clock_t) (-1)) {
1347 return false;
1348 } else {
1349 double ticks_per_second = (double) clock_tics_per_sec;
1350 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1351 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1352 *process_real_time = ((double) real_ticks) / ticks_per_second;
1353
1354 return true;
1355 }
1356 }
1357
1358
1359 char * os::local_time_string(char *buf, size_t buflen) {
1360 struct tm t;
1361 time_t long_time;
1362 time(&long_time);
1363 localtime_r(&long_time, &t);
1364 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1365 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1366 t.tm_hour, t.tm_min, t.tm_sec);
1367 return buf;
1368 }
1369
1370 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1371 return localtime_r(clock, res);
1372 }
1373
1374 ////////////////////////////////////////////////////////////////////////////////
1375 // runtime exit support
1376
1377 // Note: os::shutdown() might be called very early during initialization, or
1378 // called from signal handler. Before adding something to os::shutdown(), make
1379 // sure it is async-safe and can handle partially initialized VM.
1380 void os::shutdown() {
1381
1382 // allow PerfMemory to attempt cleanup of any persistent resources
1383 perfMemory_exit();
1384
1385 // needs to remove object in file system
1386 AttachListener::abort();
1387
1388 // flush buffered output, finish log files
1389 ostream_abort();
1390
1391 // Check for abort hook
1392 abort_hook_t abort_hook = Arguments::abort_hook();
1393 if (abort_hook != NULL) {
1394 abort_hook();
1395 }
1396
1397 }
1398
1399 // Note: os::abort() might be called very early during initialization, or
1400 // called from signal handler. Before adding something to os::abort(), make
1401 // sure it is async-safe and can handle partially initialized VM.
1402 void os::abort(bool dump_core, void* siginfo, const void* context) {
1403 os::shutdown();
1404 if (dump_core) {
1405 #ifndef PRODUCT
1406 fdStream out(defaultStream::output_fd());
1407 out.print_raw("Current thread is ");
1408 char buf[16];
1409 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1410 out.print_raw_cr(buf);
1411 out.print_raw_cr("Dumping core ...");
1412 #endif
1413 ::abort(); // dump core
1414 }
1415
1416 ::exit(1);
1417 }
1418
1419 // Die immediately, no exit hook, no abort hook, no cleanup.
1420 void os::die() {
1421 ::abort();
1422 }
1423
1424 // thread_id is kernel thread id (similar to Solaris LWP id)
1425 intx os::current_thread_id() { return os::Linux::gettid(); }
1426 int os::current_process_id() {
1427 return ::getpid();
1428 }
1429
1430 // DLL functions
1431
1432 const char* os::dll_file_extension() { return ".so"; }
1433
1434 // This must be hard coded because it's the system's temporary
1435 // directory not the java application's temp directory, ala java.io.tmpdir.
1436 const char* os::get_temp_directory() { return "/tmp"; }
1437
1438 static bool file_exists(const char* filename) {
1439 struct stat statbuf;
1440 if (filename == NULL || strlen(filename) == 0) {
1441 return false;
1442 }
1443 return os::stat(filename, &statbuf) == 0;
1444 }
1445
1446 // check if addr is inside libjvm.so
1447 bool os::address_is_in_vm(address addr) {
1448 static address libjvm_base_addr;
1449 Dl_info dlinfo;
1450
1451 if (libjvm_base_addr == NULL) {
1452 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1453 libjvm_base_addr = (address)dlinfo.dli_fbase;
1454 }
1455 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1456 }
1457
1458 if (dladdr((void *)addr, &dlinfo) != 0) {
1459 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1460 }
1461
1462 return false;
1463 }
1464
1465 bool os::dll_address_to_function_name(address addr, char *buf,
1466 int buflen, int *offset,
1467 bool demangle) {
1468 // buf is not optional, but offset is optional
1469 assert(buf != NULL, "sanity check");
1470
1471 Dl_info dlinfo;
1472
1473 if (dladdr((void*)addr, &dlinfo) != 0) {
1474 // see if we have a matching symbol
1475 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1476 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1477 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1478 }
1479 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1480 return true;
1481 }
1482 // no matching symbol so try for just file info
1483 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1484 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1485 buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1486 return true;
1487 }
1488 }
1489 }
1490
1491 buf[0] = '\0';
1492 if (offset != NULL) *offset = -1;
1493 return false;
1494 }
1495
1496 struct _address_to_library_name {
1497 address addr; // input : memory address
1498 size_t buflen; // size of fname
1499 char* fname; // output: library name
1500 address base; // library base addr
1501 };
1502
1503 static int address_to_library_name_callback(struct dl_phdr_info *info,
1504 size_t size, void *data) {
1505 int i;
1506 bool found = false;
1507 address libbase = NULL;
1508 struct _address_to_library_name * d = (struct _address_to_library_name *)data;
1509
1510 // iterate through all loadable segments
1511 for (i = 0; i < info->dlpi_phnum; i++) {
1512 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
1513 if (info->dlpi_phdr[i].p_type == PT_LOAD) {
1514 // base address of a library is the lowest address of its loaded
1515 // segments.
1516 if (libbase == NULL || libbase > segbase) {
1517 libbase = segbase;
1518 }
1519 // see if 'addr' is within current segment
1520 if (segbase <= d->addr &&
1521 d->addr < segbase + info->dlpi_phdr[i].p_memsz) {
1522 found = true;
1523 }
1524 }
1525 }
1526
1527 // dlpi_name is NULL or empty if the ELF file is executable, return 0
1528 // so dll_address_to_library_name() can fall through to use dladdr() which
1529 // can figure out executable name from argv[0].
1530 if (found && info->dlpi_name && info->dlpi_name[0]) {
1531 d->base = libbase;
1532 if (d->fname) {
1533 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name);
1534 }
1535 return 1;
1536 }
1537 return 0;
1538 }
1539
1540 bool os::dll_address_to_library_name(address addr, char* buf,
1541 int buflen, int* offset) {
1542 // buf is not optional, but offset is optional
1543 assert(buf != NULL, "sanity check");
1544
1545 Dl_info dlinfo;
1546 struct _address_to_library_name data;
1547
1548 // There is a bug in old glibc dladdr() implementation that it could resolve
1549 // to wrong library name if the .so file has a base address != NULL. Here
1550 // we iterate through the program headers of all loaded libraries to find
1551 // out which library 'addr' really belongs to. This workaround can be
1552 // removed once the minimum requirement for glibc is moved to 2.3.x.
1553 data.addr = addr;
1554 data.fname = buf;
1555 data.buflen = buflen;
1556 data.base = NULL;
1557 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data);
1558
1559 if (rslt) {
1560 // buf already contains library name
1561 if (offset) *offset = addr - data.base;
1562 return true;
1563 }
1564 if (dladdr((void*)addr, &dlinfo) != 0) {
1565 if (dlinfo.dli_fname != NULL) {
1566 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1567 }
1568 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1569 *offset = addr - (address)dlinfo.dli_fbase;
1570 }
1571 return true;
1572 }
1573
1574 buf[0] = '\0';
1575 if (offset) *offset = -1;
1576 return false;
1577 }
1578
1579 // Loads .dll/.so and
1580 // in case of error it checks if .dll/.so was built for the
1581 // same architecture as Hotspot is running on
1582
1583
1584 // Remember the stack's state. The Linux dynamic linker will change
1585 // the stack to 'executable' at most once, so we must safepoint only once.
1586 bool os::Linux::_stack_is_executable = false;
1587
1588 // VM operation that loads a library. This is necessary if stack protection
1589 // of the Java stacks can be lost during loading the library. If we
1590 // do not stop the Java threads, they can stack overflow before the stacks
1591 // are protected again.
1592 class VM_LinuxDllLoad: public VM_Operation {
1593 private:
1594 const char *_filename;
1595 char *_ebuf;
1596 int _ebuflen;
1597 void *_lib;
1598 public:
1599 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) :
1600 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {}
1601 VMOp_Type type() const { return VMOp_LinuxDllLoad; }
1602 void doit() {
1603 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen);
1604 os::Linux::_stack_is_executable = true;
1605 }
1606 void* loaded_library() { return _lib; }
1607 };
1608
1609 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1610 void * result = NULL;
1611 bool load_attempted = false;
1612
1613 // Check whether the library to load might change execution rights
1614 // of the stack. If they are changed, the protection of the stack
1615 // guard pages will be lost. We need a safepoint to fix this.
1616 //
1617 // See Linux man page execstack(8) for more info.
1618 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) {
1619 if (!ElfFile::specifies_noexecstack(filename)) {
1620 if (!is_init_completed()) {
1621 os::Linux::_stack_is_executable = true;
1622 // This is OK - No Java threads have been created yet, and hence no
1623 // stack guard pages to fix.
1624 //
1625 // This should happen only when you are building JDK7 using a very
1626 // old version of JDK6 (e.g., with JPRT) and running test_gamma.
1627 //
1628 // Dynamic loader will make all stacks executable after
1629 // this function returns, and will not do that again.
1630 assert(Threads::number_of_threads() == 0, "no Java threads should exist yet.");
1631 } else {
1632 warning("You have loaded library %s which might have disabled stack guard. "
1633 "The VM will try to fix the stack guard now.\n"
1634 "It's highly recommended that you fix the library with "
1635 "'execstack -c <libfile>', or link it with '-z noexecstack'.",
1636 filename);
1637
1638 assert(Thread::current()->is_Java_thread(), "must be Java thread");
1639 JavaThread *jt = JavaThread::current();
1640 if (jt->thread_state() != _thread_in_native) {
1641 // This happens when a compiler thread tries to load a hsdis-<arch>.so file
1642 // that requires ExecStack. Cannot enter safe point. Let's give up.
1643 warning("Unable to fix stack guard. Giving up.");
1644 } else {
1645 if (!LoadExecStackDllInVMThread) {
1646 // This is for the case where the DLL has an static
1647 // constructor function that executes JNI code. We cannot
1648 // load such DLLs in the VMThread.
1649 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1650 }
1651
1652 ThreadInVMfromNative tiv(jt);
1653 debug_only(VMNativeEntryWrapper vew;)
1654
1655 VM_LinuxDllLoad op(filename, ebuf, ebuflen);
1656 VMThread::execute(&op);
1657 if (LoadExecStackDllInVMThread) {
1658 result = op.loaded_library();
1659 }
1660 load_attempted = true;
1661 }
1662 }
1663 }
1664 }
1665
1666 if (!load_attempted) {
1667 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1668 }
1669
1670 if (result != NULL) {
1671 // Successful loading
1672 return result;
1673 }
1674
1675 Elf32_Ehdr elf_head;
1676 int diag_msg_max_length=ebuflen-strlen(ebuf);
1677 char* diag_msg_buf=ebuf+strlen(ebuf);
1678
1679 if (diag_msg_max_length==0) {
1680 // No more space in ebuf for additional diagnostics message
1681 return NULL;
1682 }
1683
1684
1685 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1686
1687 if (file_descriptor < 0) {
1688 // Can't open library, report dlerror() message
1689 return NULL;
1690 }
1691
1692 bool failed_to_read_elf_head=
1693 (sizeof(elf_head)!=
1694 (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1695
1696 ::close(file_descriptor);
1697 if (failed_to_read_elf_head) {
1698 // file i/o error - report dlerror() msg
1699 return NULL;
1700 }
1701
1702 typedef struct {
1703 Elf32_Half code; // Actual value as defined in elf.h
1704 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1705 unsigned char elf_class; // 32 or 64 bit
1706 unsigned char endianess; // MSB or LSB
1707 char* name; // String representation
1708 } arch_t;
1709
1710 #ifndef EM_486
1711 #define EM_486 6 /* Intel 80486 */
1712 #endif
1713 #ifndef EM_AARCH64
1714 #define EM_AARCH64 183 /* ARM AARCH64 */
1715 #endif
1716
1717 static const arch_t arch_array[]={
1718 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1719 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1720 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1721 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1722 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1723 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1724 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1725 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1726 #if defined(VM_LITTLE_ENDIAN)
1727 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"},
1728 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"},
1729 #else
1730 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1731 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"},
1732 #endif
1733 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1734 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1735 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1736 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1737 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1738 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1739 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"},
1740 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"},
1741 };
1742
1743 #if (defined IA32)
1744 static Elf32_Half running_arch_code=EM_386;
1745 #elif (defined AMD64) || (defined X32)
1746 static Elf32_Half running_arch_code=EM_X86_64;
1747 #elif (defined IA64)
1748 static Elf32_Half running_arch_code=EM_IA_64;
1749 #elif (defined __sparc) && (defined _LP64)
1750 static Elf32_Half running_arch_code=EM_SPARCV9;
1751 #elif (defined __sparc) && (!defined _LP64)
1752 static Elf32_Half running_arch_code=EM_SPARC;
1753 #elif (defined __powerpc64__)
1754 static Elf32_Half running_arch_code=EM_PPC64;
1755 #elif (defined __powerpc__)
1756 static Elf32_Half running_arch_code=EM_PPC;
1757 #elif (defined AARCH64)
1758 static Elf32_Half running_arch_code=EM_AARCH64;
1759 #elif (defined ARM)
1760 static Elf32_Half running_arch_code=EM_ARM;
1761 #elif (defined S390)
1762 static Elf32_Half running_arch_code=EM_S390;
1763 #elif (defined ALPHA)
1764 static Elf32_Half running_arch_code=EM_ALPHA;
1765 #elif (defined MIPSEL)
1766 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1767 #elif (defined PARISC)
1768 static Elf32_Half running_arch_code=EM_PARISC;
1769 #elif (defined MIPS)
1770 static Elf32_Half running_arch_code=EM_MIPS;
1771 #elif (defined M68K)
1772 static Elf32_Half running_arch_code=EM_68K;
1773 #elif (defined SH)
1774 static Elf32_Half running_arch_code=EM_SH;
1775 #else
1776 #error Method os::dll_load requires that one of following is defined:\
1777 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc
1778 #endif
1779
1780 // Identify compatability class for VM's architecture and library's architecture
1781 // Obtain string descriptions for architectures
1782
1783 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1784 int running_arch_index=-1;
1785
1786 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1787 if (running_arch_code == arch_array[i].code) {
1788 running_arch_index = i;
1789 }
1790 if (lib_arch.code == arch_array[i].code) {
1791 lib_arch.compat_class = arch_array[i].compat_class;
1792 lib_arch.name = arch_array[i].name;
1793 }
1794 }
1795
1796 assert(running_arch_index != -1,
1797 "Didn't find running architecture code (running_arch_code) in arch_array");
1798 if (running_arch_index == -1) {
1799 // Even though running architecture detection failed
1800 // we may still continue with reporting dlerror() message
1801 return NULL;
1802 }
1803
1804 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1805 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1806 return NULL;
1807 }
1808
1809 #ifndef S390
1810 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1811 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1812 return NULL;
1813 }
1814 #endif // !S390
1815
1816 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1817 if (lib_arch.name!=NULL) {
1818 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1819 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1820 lib_arch.name, arch_array[running_arch_index].name);
1821 } else {
1822 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1823 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1824 lib_arch.code,
1825 arch_array[running_arch_index].name);
1826 }
1827 }
1828
1829 return NULL;
1830 }
1831
1832 void * os::Linux::dlopen_helper(const char *filename, char *ebuf,
1833 int ebuflen) {
1834 void * result = ::dlopen(filename, RTLD_LAZY);
1835 if (result == NULL) {
1836 ::strncpy(ebuf, ::dlerror(), ebuflen - 1);
1837 ebuf[ebuflen-1] = '\0';
1838 }
1839 return result;
1840 }
1841
1842 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf,
1843 int ebuflen) {
1844 void * result = NULL;
1845 if (LoadExecStackDllInVMThread) {
1846 result = dlopen_helper(filename, ebuf, ebuflen);
1847 }
1848
1849 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a
1850 // library that requires an executable stack, or which does not have this
1851 // stack attribute set, dlopen changes the stack attribute to executable. The
1852 // read protection of the guard pages gets lost.
1853 //
1854 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad
1855 // may have been queued at the same time.
1856
1857 if (!_stack_is_executable) {
1858 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
1859 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized
1860 jt->stack_guards_enabled()) { // No pending stack overflow exceptions
1861 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) {
1862 warning("Attempt to reguard stack yellow zone failed.");
1863 }
1864 }
1865 }
1866 }
1867
1868 return result;
1869 }
1870
1871 void* os::dll_lookup(void* handle, const char* name) {
1872 void* res = dlsym(handle, name);
1873 return res;
1874 }
1875
1876 void* os::get_default_process_handle() {
1877 return (void*)::dlopen(NULL, RTLD_LAZY);
1878 }
1879
1880 static bool _print_ascii_file(const char* filename, outputStream* st, const char* hdr = NULL) {
1881 int fd = ::open(filename, O_RDONLY);
1882 if (fd == -1) {
1883 return false;
1884 }
1885
1886 if (hdr != NULL) {
1887 st->print_cr("%s", hdr);
1888 }
1889
1890 char buf[33];
1891 int bytes;
1892 buf[32] = '\0';
1893 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) {
1894 st->print_raw(buf, bytes);
1895 }
1896
1897 ::close(fd);
1898
1899 return true;
1900 }
1901
1902 void os::print_dll_info(outputStream *st) {
1903 st->print_cr("Dynamic libraries:");
1904
1905 char fname[32];
1906 pid_t pid = os::Linux::gettid();
1907
1908 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid);
1909
1910 if (!_print_ascii_file(fname, st)) {
1911 st->print("Can not get library information for pid = %d\n", pid);
1912 }
1913 }
1914
1915 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1916 FILE *procmapsFile = NULL;
1917
1918 // Open the procfs maps file for the current process
1919 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) {
1920 // Allocate PATH_MAX for file name plus a reasonable size for other fields.
1921 char line[PATH_MAX + 100];
1922
1923 // Read line by line from 'file'
1924 while (fgets(line, sizeof(line), procmapsFile) != NULL) {
1925 u8 base, top, offset, inode;
1926 char permissions[5];
1927 char device[6];
1928 char name[PATH_MAX + 1];
1929
1930 // Parse fields from line
1931 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s",
1932 &base, &top, permissions, &offset, device, &inode, name);
1933
1934 // Filter by device id '00:00' so that we only get file system mapped files.
1935 if (strcmp(device, "00:00") != 0) {
1936
1937 // Call callback with the fields of interest
1938 if(callback(name, (address)base, (address)top, param)) {
1939 // Oops abort, callback aborted
1940 fclose(procmapsFile);
1941 return 1;
1942 }
1943 }
1944 }
1945 fclose(procmapsFile);
1946 }
1947 return 0;
1948 }
1949
1950 void os::print_os_info_brief(outputStream* st) {
1951 os::Linux::print_distro_info(st);
1952
1953 os::Posix::print_uname_info(st);
1954
1955 os::Linux::print_libversion_info(st);
1956
1957 }
1958
1959 void os::print_os_info(outputStream* st) {
1960 st->print("OS:");
1961
1962 os::Linux::print_distro_info(st);
1963
1964 os::Posix::print_uname_info(st);
1965
1966 // Print warning if unsafe chroot environment detected
1967 if (unsafe_chroot_detected) {
1968 st->print("WARNING!! ");
1969 st->print_cr("%s", unstable_chroot_error);
1970 }
1971
1972 os::Linux::print_libversion_info(st);
1973
1974 os::Posix::print_rlimit_info(st);
1975
1976 os::Posix::print_load_average(st);
1977
1978 os::Linux::print_full_memory_info(st);
1979
1980 os::Linux::print_proc_sys_info(st);
1981
1982 os::Linux::print_ld_preload_file(st);
1983
1984 os::Linux::print_container_info(st);
1985 }
1986
1987 // Try to identify popular distros.
1988 // Most Linux distributions have a /etc/XXX-release file, which contains
1989 // the OS version string. Newer Linux distributions have a /etc/lsb-release
1990 // file that also contains the OS version string. Some have more than one
1991 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and
1992 // /etc/redhat-release.), so the order is important.
1993 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have
1994 // their own specific XXX-release file as well as a redhat-release file.
1995 // Because of this the XXX-release file needs to be searched for before the
1996 // redhat-release file.
1997 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the
1998 // search for redhat-release / SuSE-release needs to be before lsb-release.
1999 // Since the lsb-release file is the new standard it needs to be searched
2000 // before the older style release files.
2001 // Searching system-release (Red Hat) and os-release (other Linuxes) are a
2002 // next to last resort. The os-release file is a new standard that contains
2003 // distribution information and the system-release file seems to be an old
2004 // standard that has been replaced by the lsb-release and os-release files.
2005 // Searching for the debian_version file is the last resort. It contains
2006 // an informative string like "6.0.6" or "wheezy/sid". Because of this
2007 // "Debian " is printed before the contents of the debian_version file.
2008
2009 const char* distro_files[] = {
2010 "/etc/oracle-release",
2011 "/etc/mandriva-release",
2012 "/etc/mandrake-release",
2013 "/etc/sun-release",
2014 "/etc/redhat-release",
2015 "/etc/SuSE-release",
2016 "/etc/lsb-release",
2017 "/etc/turbolinux-release",
2018 "/etc/gentoo-release",
2019 "/etc/ltib-release",
2020 "/etc/angstrom-version",
2021 "/etc/system-release",
2022 "/etc/os-release",
2023 NULL };
2024
2025 void os::Linux::print_distro_info(outputStream* st) {
2026 for (int i = 0;; i++) {
2027 const char* file = distro_files[i];
2028 if (file == NULL) {
2029 break; // done
2030 }
2031 // If file prints, we found it.
2032 if (_print_ascii_file(file, st)) {
2033 return;
2034 }
2035 }
2036
2037 if (file_exists("/etc/debian_version")) {
2038 st->print("Debian ");
2039 _print_ascii_file("/etc/debian_version", st);
2040 } else {
2041 st->print("Linux");
2042 }
2043 st->cr();
2044 }
2045
2046 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) {
2047 char buf[256];
2048 while (fgets(buf, sizeof(buf), fp)) {
2049 // Edit out extra stuff in expected format
2050 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) {
2051 char* ptr = strstr(buf, "\""); // the name is in quotes
2052 if (ptr != NULL) {
2053 ptr++; // go beyond first quote
2054 char* nl = strchr(ptr, '\"');
2055 if (nl != NULL) *nl = '\0';
2056 strncpy(distro, ptr, length);
2057 } else {
2058 ptr = strstr(buf, "=");
2059 ptr++; // go beyond equals then
2060 char* nl = strchr(ptr, '\n');
2061 if (nl != NULL) *nl = '\0';
2062 strncpy(distro, ptr, length);
2063 }
2064 return;
2065 } else if (get_first_line) {
2066 char* nl = strchr(buf, '\n');
2067 if (nl != NULL) *nl = '\0';
2068 strncpy(distro, buf, length);
2069 return;
2070 }
2071 }
2072 // print last line and close
2073 char* nl = strchr(buf, '\n');
2074 if (nl != NULL) *nl = '\0';
2075 strncpy(distro, buf, length);
2076 }
2077
2078 static void parse_os_info(char* distro, size_t length, const char* file) {
2079 FILE* fp = fopen(file, "r");
2080 if (fp != NULL) {
2081 // if suse format, print out first line
2082 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0);
2083 parse_os_info_helper(fp, distro, length, get_first_line);
2084 fclose(fp);
2085 }
2086 }
2087
2088 void os::get_summary_os_info(char* buf, size_t buflen) {
2089 for (int i = 0;; i++) {
2090 const char* file = distro_files[i];
2091 if (file == NULL) {
2092 break; // ran out of distro_files
2093 }
2094 if (file_exists(file)) {
2095 parse_os_info(buf, buflen, file);
2096 return;
2097 }
2098 }
2099 // special case for debian
2100 if (file_exists("/etc/debian_version")) {
2101 strncpy(buf, "Debian ", buflen);
2102 if (buflen > 7) {
2103 parse_os_info(&buf[7], buflen-7, "/etc/debian_version");
2104 }
2105 } else {
2106 strncpy(buf, "Linux", buflen);
2107 }
2108 }
2109
2110 void os::Linux::print_libversion_info(outputStream* st) {
2111 // libc, pthread
2112 st->print("libc:");
2113 st->print("%s ", os::Linux::glibc_version());
2114 st->print("%s ", os::Linux::libpthread_version());
2115 st->cr();
2116 }
2117
2118 void os::Linux::print_proc_sys_info(outputStream* st) {
2119 st->cr();
2120 st->print_cr("/proc/sys/kernel/threads-max (system-wide limit on the number of threads):");
2121 _print_ascii_file("/proc/sys/kernel/threads-max", st);
2122 st->cr();
2123 st->cr();
2124
2125 st->print_cr("/proc/sys/vm/max_map_count (maximum number of memory map areas a process may have):");
2126 _print_ascii_file("/proc/sys/vm/max_map_count", st);
2127 st->cr();
2128 st->cr();
2129
2130 st->print_cr("/proc/sys/kernel/pid_max (system-wide limit on number of process identifiers):");
2131 _print_ascii_file("/proc/sys/kernel/pid_max", st);
2132 st->cr();
2133 st->cr();
2134 }
2135
2136 void os::Linux::print_full_memory_info(outputStream* st) {
2137 st->print("\n/proc/meminfo:\n");
2138 _print_ascii_file("/proc/meminfo", st);
2139 st->cr();
2140 }
2141
2142 void os::Linux::print_ld_preload_file(outputStream* st) {
2143 _print_ascii_file("/etc/ld.so.preload", st, "\n/etc/ld.so.preload:");
2144 st->cr();
2145 }
2146
2147 void os::Linux::print_container_info(outputStream* st) {
2148 if (!OSContainer::is_containerized()) {
2149 return;
2150 }
2151
2152 st->print("container (cgroup) information:\n");
2153
2154 const char *p_ct = OSContainer::container_type();
2155 st->print("container_type: %s\n", p_ct != NULL ? p_ct : "failed");
2156
2157 char *p = OSContainer::cpu_cpuset_cpus();
2158 st->print("cpu_cpuset_cpus: %s\n", p != NULL ? p : "failed");
2159 free(p);
2160
2161 p = OSContainer::cpu_cpuset_memory_nodes();
2162 st->print("cpu_memory_nodes: %s\n", p != NULL ? p : "failed");
2163 free(p);
2164
2165 int i = OSContainer::active_processor_count();
2166 if (i > 0) {
2167 st->print("active_processor_count: %d\n", i);
2168 } else {
2169 st->print("active_processor_count: failed\n");
2170 }
2171
2172 i = OSContainer::cpu_quota();
2173 st->print("cpu_quota: %d\n", i);
2174
2175 i = OSContainer::cpu_period();
2176 st->print("cpu_period: %d\n", i);
2177
2178 i = OSContainer::cpu_shares();
2179 st->print("cpu_shares: %d\n", i);
2180
2181 jlong j = OSContainer::memory_limit_in_bytes();
2182 st->print("memory_limit_in_bytes: " JLONG_FORMAT "\n", j);
2183
2184 j = OSContainer::memory_and_swap_limit_in_bytes();
2185 st->print("memory_and_swap_limit_in_bytes: " JLONG_FORMAT "\n", j);
2186
2187 j = OSContainer::memory_soft_limit_in_bytes();
2188 st->print("memory_soft_limit_in_bytes: " JLONG_FORMAT "\n", j);
2189
2190 j = OSContainer::OSContainer::memory_usage_in_bytes();
2191 st->print("memory_usage_in_bytes: " JLONG_FORMAT "\n", j);
2192
2193 j = OSContainer::OSContainer::memory_max_usage_in_bytes();
2194 st->print("memory_max_usage_in_bytes: " JLONG_FORMAT "\n", j);
2195 st->cr();
2196 }
2197
2198 void os::print_memory_info(outputStream* st) {
2199
2200 st->print("Memory:");
2201 st->print(" %dk page", os::vm_page_size()>>10);
2202
2203 // values in struct sysinfo are "unsigned long"
2204 struct sysinfo si;
2205 sysinfo(&si);
2206
2207 st->print(", physical " UINT64_FORMAT "k",
2208 os::physical_memory() >> 10);
2209 st->print("(" UINT64_FORMAT "k free)",
2210 os::available_memory() >> 10);
2211 st->print(", swap " UINT64_FORMAT "k",
2212 ((jlong)si.totalswap * si.mem_unit) >> 10);
2213 st->print("(" UINT64_FORMAT "k free)",
2214 ((jlong)si.freeswap * si.mem_unit) >> 10);
2215 st->cr();
2216 }
2217
2218 // Print the first "model name" line and the first "flags" line
2219 // that we find and nothing more. We assume "model name" comes
2220 // before "flags" so if we find a second "model name", then the
2221 // "flags" field is considered missing.
2222 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) {
2223 #if defined(IA32) || defined(AMD64)
2224 // Other platforms have less repetitive cpuinfo files
2225 FILE *fp = fopen("/proc/cpuinfo", "r");
2226 if (fp) {
2227 while (!feof(fp)) {
2228 if (fgets(buf, buflen, fp)) {
2229 // Assume model name comes before flags
2230 bool model_name_printed = false;
2231 if (strstr(buf, "model name") != NULL) {
2232 if (!model_name_printed) {
2233 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n");
2234 st->print_raw(buf);
2235 model_name_printed = true;
2236 } else {
2237 // model name printed but not flags? Odd, just return
2238 fclose(fp);
2239 return true;
2240 }
2241 }
2242 // print the flags line too
2243 if (strstr(buf, "flags") != NULL) {
2244 st->print_raw(buf);
2245 fclose(fp);
2246 return true;
2247 }
2248 }
2249 }
2250 fclose(fp);
2251 }
2252 #endif // x86 platforms
2253 return false;
2254 }
2255
2256 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
2257 // Only print the model name if the platform provides this as a summary
2258 if (!print_model_name_and_flags(st, buf, buflen)) {
2259 st->print("\n/proc/cpuinfo:\n");
2260 if (!_print_ascii_file("/proc/cpuinfo", st)) {
2261 st->print_cr(" <Not Available>");
2262 }
2263 }
2264 }
2265
2266 #if defined(AMD64) || defined(IA32) || defined(X32)
2267 const char* search_string = "model name";
2268 #elif defined(M68K)
2269 const char* search_string = "CPU";
2270 #elif defined(PPC64)
2271 const char* search_string = "cpu";
2272 #elif defined(S390)
2273 const char* search_string = "processor";
2274 #elif defined(SPARC)
2275 const char* search_string = "cpu";
2276 #else
2277 const char* search_string = "Processor";
2278 #endif
2279
2280 // Parses the cpuinfo file for string representing the model name.
2281 void os::get_summary_cpu_info(char* cpuinfo, size_t length) {
2282 FILE* fp = fopen("/proc/cpuinfo", "r");
2283 if (fp != NULL) {
2284 while (!feof(fp)) {
2285 char buf[256];
2286 if (fgets(buf, sizeof(buf), fp)) {
2287 char* start = strstr(buf, search_string);
2288 if (start != NULL) {
2289 char *ptr = start + strlen(search_string);
2290 char *end = buf + strlen(buf);
2291 while (ptr != end) {
2292 // skip whitespace and colon for the rest of the name.
2293 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') {
2294 break;
2295 }
2296 ptr++;
2297 }
2298 if (ptr != end) {
2299 // reasonable string, get rid of newline and keep the rest
2300 char* nl = strchr(buf, '\n');
2301 if (nl != NULL) *nl = '\0';
2302 strncpy(cpuinfo, ptr, length);
2303 fclose(fp);
2304 return;
2305 }
2306 }
2307 }
2308 }
2309 fclose(fp);
2310 }
2311 // cpuinfo not found or parsing failed, just print generic string. The entire
2312 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86)
2313 #if defined(AARCH64)
2314 strncpy(cpuinfo, "AArch64", length);
2315 #elif defined(AMD64)
2316 strncpy(cpuinfo, "x86_64", length);
2317 #elif defined(ARM) // Order wrt. AARCH64 is relevant!
2318 strncpy(cpuinfo, "ARM", length);
2319 #elif defined(IA32)
2320 strncpy(cpuinfo, "x86_32", length);
2321 #elif defined(IA64)
2322 strncpy(cpuinfo, "IA64", length);
2323 #elif defined(PPC)
2324 strncpy(cpuinfo, "PPC64", length);
2325 #elif defined(S390)
2326 strncpy(cpuinfo, "S390", length);
2327 #elif defined(SPARC)
2328 strncpy(cpuinfo, "sparcv9", length);
2329 #elif defined(ZERO_LIBARCH)
2330 strncpy(cpuinfo, ZERO_LIBARCH, length);
2331 #else
2332 strncpy(cpuinfo, "unknown", length);
2333 #endif
2334 }
2335
2336 static void print_signal_handler(outputStream* st, int sig,
2337 char* buf, size_t buflen);
2338
2339 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
2340 st->print_cr("Signal Handlers:");
2341 print_signal_handler(st, SIGSEGV, buf, buflen);
2342 print_signal_handler(st, SIGBUS , buf, buflen);
2343 print_signal_handler(st, SIGFPE , buf, buflen);
2344 print_signal_handler(st, SIGPIPE, buf, buflen);
2345 print_signal_handler(st, SIGXFSZ, buf, buflen);
2346 print_signal_handler(st, SIGILL , buf, buflen);
2347 print_signal_handler(st, SR_signum, buf, buflen);
2348 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
2349 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
2350 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
2351 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
2352 #if defined(PPC64)
2353 print_signal_handler(st, SIGTRAP, buf, buflen);
2354 #endif
2355 }
2356
2357 static char saved_jvm_path[MAXPATHLEN] = {0};
2358
2359 // Find the full path to the current module, libjvm.so
2360 void os::jvm_path(char *buf, jint buflen) {
2361 // Error checking.
2362 if (buflen < MAXPATHLEN) {
2363 assert(false, "must use a large-enough buffer");
2364 buf[0] = '\0';
2365 return;
2366 }
2367 // Lazy resolve the path to current module.
2368 if (saved_jvm_path[0] != 0) {
2369 strcpy(buf, saved_jvm_path);
2370 return;
2371 }
2372
2373 char dli_fname[MAXPATHLEN];
2374 bool ret = dll_address_to_library_name(
2375 CAST_FROM_FN_PTR(address, os::jvm_path),
2376 dli_fname, sizeof(dli_fname), NULL);
2377 assert(ret, "cannot locate libjvm");
2378 char *rp = NULL;
2379 if (ret && dli_fname[0] != '\0') {
2380 rp = os::Posix::realpath(dli_fname, buf, buflen);
2381 }
2382 if (rp == NULL) {
2383 return;
2384 }
2385
2386 if (Arguments::sun_java_launcher_is_altjvm()) {
2387 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
2388 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
2389 // If "/jre/lib/" appears at the right place in the string, then
2390 // assume we are installed in a JDK and we're done. Otherwise, check
2391 // for a JAVA_HOME environment variable and fix up the path so it
2392 // looks like libjvm.so is installed there (append a fake suffix
2393 // hotspot/libjvm.so).
2394 const char *p = buf + strlen(buf) - 1;
2395 for (int count = 0; p > buf && count < 5; ++count) {
2396 for (--p; p > buf && *p != '/'; --p)
2397 /* empty */ ;
2398 }
2399
2400 if (strncmp(p, "/jre/lib/", 9) != 0) {
2401 // Look for JAVA_HOME in the environment.
2402 char* java_home_var = ::getenv("JAVA_HOME");
2403 if (java_home_var != NULL && java_home_var[0] != 0) {
2404 char* jrelib_p;
2405 int len;
2406
2407 // Check the current module name "libjvm.so".
2408 p = strrchr(buf, '/');
2409 if (p == NULL) {
2410 return;
2411 }
2412 assert(strstr(p, "/libjvm") == p, "invalid library name");
2413
2414 rp = os::Posix::realpath(java_home_var, buf, buflen);
2415 if (rp == NULL) {
2416 return;
2417 }
2418
2419 // determine if this is a legacy image or modules image
2420 // modules image doesn't have "jre" subdirectory
2421 len = strlen(buf);
2422 assert(len < buflen, "Ran out of buffer room");
2423 jrelib_p = buf + len;
2424 snprintf(jrelib_p, buflen-len, "/jre/lib");
2425 if (0 != access(buf, F_OK)) {
2426 snprintf(jrelib_p, buflen-len, "/lib");
2427 }
2428
2429 if (0 == access(buf, F_OK)) {
2430 // Use current module name "libjvm.so"
2431 len = strlen(buf);
2432 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
2433 } else {
2434 // Go back to path of .so
2435 rp = os::Posix::realpath(dli_fname, buf, buflen);
2436 if (rp == NULL) {
2437 return;
2438 }
2439 }
2440 }
2441 }
2442 }
2443
2444 strncpy(saved_jvm_path, buf, MAXPATHLEN);
2445 saved_jvm_path[MAXPATHLEN - 1] = '\0';
2446 }
2447
2448 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
2449 // no prefix required, not even "_"
2450 }
2451
2452 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
2453 // no suffix required
2454 }
2455
2456 ////////////////////////////////////////////////////////////////////////////////
2457 // sun.misc.Signal support
2458
2459 static volatile jint sigint_count = 0;
2460
2461 static void UserHandler(int sig, void *siginfo, void *context) {
2462 // 4511530 - sem_post is serialized and handled by the manager thread. When
2463 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
2464 // don't want to flood the manager thread with sem_post requests.
2465 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
2466 return;
2467 }
2468
2469 // Ctrl-C is pressed during error reporting, likely because the error
2470 // handler fails to abort. Let VM die immediately.
2471 if (sig == SIGINT && VMError::is_error_reported()) {
2472 os::die();
2473 }
2474
2475 os::signal_notify(sig);
2476 }
2477
2478 void* os::user_handler() {
2479 return CAST_FROM_FN_PTR(void*, UserHandler);
2480 }
2481
2482 static struct timespec create_semaphore_timespec(unsigned int sec, int nsec) {
2483 struct timespec ts;
2484 // Semaphore's are always associated with CLOCK_REALTIME
2485 os::Linux::clock_gettime(CLOCK_REALTIME, &ts);
2486 // see os_posix.cpp for discussion on overflow checking
2487 if (sec >= MAX_SECS) {
2488 ts.tv_sec += MAX_SECS;
2489 ts.tv_nsec = 0;
2490 } else {
2491 ts.tv_sec += sec;
2492 ts.tv_nsec += nsec;
2493 if (ts.tv_nsec >= NANOSECS_PER_SEC) {
2494 ts.tv_nsec -= NANOSECS_PER_SEC;
2495 ++ts.tv_sec; // note: this must be <= max_secs
2496 }
2497 }
2498
2499 return ts;
2500 }
2501
2502 extern "C" {
2503 typedef void (*sa_handler_t)(int);
2504 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
2505 }
2506
2507 void* os::signal(int signal_number, void* handler) {
2508 struct sigaction sigAct, oldSigAct;
2509
2510 sigfillset(&(sigAct.sa_mask));
2511 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
2512 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
2513
2514 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
2515 // -1 means registration failed
2516 return (void *)-1;
2517 }
2518
2519 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
2520 }
2521
2522 void os::signal_raise(int signal_number) {
2523 ::raise(signal_number);
2524 }
2525
2526 // The following code is moved from os.cpp for making this
2527 // code platform specific, which it is by its very nature.
2528
2529 // Will be modified when max signal is changed to be dynamic
2530 int os::sigexitnum_pd() {
2531 return NSIG;
2532 }
2533
2534 // a counter for each possible signal value
2535 static volatile jint pending_signals[NSIG+1] = { 0 };
2536
2537 // Linux(POSIX) specific hand shaking semaphore.
2538 static Semaphore* sig_sem = NULL;
2539 static PosixSemaphore sr_semaphore;
2540
2541 static void jdk_misc_signal_init() {
2542 // Initialize signal structures
2543 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2544
2545 // Initialize signal semaphore
2546 sig_sem = new Semaphore();
2547 }
2548
2549 void os::signal_notify(int sig) {
2550 if (sig_sem != NULL) {
2551 Atomic::inc(&pending_signals[sig]);
2552 sig_sem->signal();
2553 } else {
2554 // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
2555 // initialization isn't called.
2556 assert(ReduceSignalUsage, "signal semaphore should be created");
2557 }
2558 }
2559
2560 static int check_pending_signals() {
2561 Atomic::store(0, &sigint_count);
2562 for (;;) {
2563 for (int i = 0; i < NSIG + 1; i++) {
2564 jint n = pending_signals[i];
2565 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2566 return i;
2567 }
2568 }
2569 JavaThread *thread = JavaThread::current();
2570 ThreadBlockInVM tbivm(thread);
2571
2572 bool threadIsSuspended;
2573 do {
2574 thread->set_suspend_equivalent();
2575 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2576 sig_sem->wait();
2577
2578 // were we externally suspended while we were waiting?
2579 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2580 if (threadIsSuspended) {
2581 // The semaphore has been incremented, but while we were waiting
2582 // another thread suspended us. We don't want to continue running
2583 // while suspended because that would surprise the thread that
2584 // suspended us.
2585 sig_sem->signal();
2586
2587 thread->java_suspend_self();
2588 }
2589 } while (threadIsSuspended);
2590 }
2591 }
2592
2593 int os::signal_wait() {
2594 return check_pending_signals();
2595 }
2596
2597 ////////////////////////////////////////////////////////////////////////////////
2598 // Virtual Memory
2599
2600 int os::vm_page_size() {
2601 // Seems redundant as all get out
2602 assert(os::Linux::page_size() != -1, "must call os::init");
2603 return os::Linux::page_size();
2604 }
2605
2606 // Solaris allocates memory by pages.
2607 int os::vm_allocation_granularity() {
2608 assert(os::Linux::page_size() != -1, "must call os::init");
2609 return os::Linux::page_size();
2610 }
2611
2612 // Rationale behind this function:
2613 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2614 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2615 // samples for JITted code. Here we create private executable mapping over the code cache
2616 // and then we can use standard (well, almost, as mapping can change) way to provide
2617 // info for the reporting script by storing timestamp and location of symbol
2618 void linux_wrap_code(char* base, size_t size) {
2619 static volatile jint cnt = 0;
2620
2621 if (!UseOprofile) {
2622 return;
2623 }
2624
2625 char buf[PATH_MAX+1];
2626 int num = Atomic::add(1, &cnt);
2627
2628 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d",
2629 os::get_temp_directory(), os::current_process_id(), num);
2630 unlink(buf);
2631
2632 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2633
2634 if (fd != -1) {
2635 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2636 if (rv != (off_t)-1) {
2637 if (::write(fd, "", 1) == 1) {
2638 mmap(base, size,
2639 PROT_READ|PROT_WRITE|PROT_EXEC,
2640 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2641 }
2642 }
2643 ::close(fd);
2644 unlink(buf);
2645 }
2646 }
2647
2648 static bool recoverable_mmap_error(int err) {
2649 // See if the error is one we can let the caller handle. This
2650 // list of errno values comes from JBS-6843484. I can't find a
2651 // Linux man page that documents this specific set of errno
2652 // values so while this list currently matches Solaris, it may
2653 // change as we gain experience with this failure mode.
2654 switch (err) {
2655 case EBADF:
2656 case EINVAL:
2657 case ENOTSUP:
2658 // let the caller deal with these errors
2659 return true;
2660
2661 default:
2662 // Any remaining errors on this OS can cause our reserved mapping
2663 // to be lost. That can cause confusion where different data
2664 // structures think they have the same memory mapped. The worst
2665 // scenario is if both the VM and a library think they have the
2666 // same memory mapped.
2667 return false;
2668 }
2669 }
2670
2671 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2672 int err) {
2673 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2674 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
2675 os::strerror(err), err);
2676 }
2677
2678 static void warn_fail_commit_memory(char* addr, size_t size,
2679 size_t alignment_hint, bool exec,
2680 int err) {
2681 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2682 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size,
2683 alignment_hint, exec, os::strerror(err), err);
2684 }
2685
2686 // NOTE: Linux kernel does not really reserve the pages for us.
2687 // All it does is to check if there are enough free pages
2688 // left at the time of mmap(). This could be a potential
2689 // problem.
2690 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) {
2691 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2692 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2693 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2694 if (res != (uintptr_t) MAP_FAILED) {
2695 if (UseNUMAInterleaving) {
2696 numa_make_global(addr, size);
2697 }
2698 return 0;
2699 }
2700
2701 int err = errno; // save errno from mmap() call above
2702
2703 if (!recoverable_mmap_error(err)) {
2704 warn_fail_commit_memory(addr, size, exec, err);
2705 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory.");
2706 }
2707
2708 return err;
2709 }
2710
2711 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2712 return os::Linux::commit_memory_impl(addr, size, exec) == 0;
2713 }
2714
2715 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2716 const char* mesg) {
2717 assert(mesg != NULL, "mesg must be specified");
2718 int err = os::Linux::commit_memory_impl(addr, size, exec);
2719 if (err != 0) {
2720 // the caller wants all commit errors to exit with the specified mesg:
2721 warn_fail_commit_memory(addr, size, exec, err);
2722 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2723 }
2724 }
2725
2726 // Define MAP_HUGETLB here so we can build HotSpot on old systems.
2727 #ifndef MAP_HUGETLB
2728 #define MAP_HUGETLB 0x40000
2729 #endif
2730
2731 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems.
2732 #ifndef MADV_HUGEPAGE
2733 #define MADV_HUGEPAGE 14
2734 #endif
2735
2736 int os::Linux::commit_memory_impl(char* addr, size_t size,
2737 size_t alignment_hint, bool exec) {
2738 int err = os::Linux::commit_memory_impl(addr, size, exec);
2739 if (err == 0) {
2740 realign_memory(addr, size, alignment_hint);
2741 }
2742 return err;
2743 }
2744
2745 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2746 bool exec) {
2747 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0;
2748 }
2749
2750 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2751 size_t alignment_hint, bool exec,
2752 const char* mesg) {
2753 assert(mesg != NULL, "mesg must be specified");
2754 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec);
2755 if (err != 0) {
2756 // the caller wants all commit errors to exit with the specified mesg:
2757 warn_fail_commit_memory(addr, size, alignment_hint, exec, err);
2758 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2759 }
2760 }
2761
2762 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2763 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) {
2764 // We don't check the return value: madvise(MADV_HUGEPAGE) may not
2765 // be supported or the memory may already be backed by huge pages.
2766 ::madvise(addr, bytes, MADV_HUGEPAGE);
2767 }
2768 }
2769
2770 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2771 // This method works by doing an mmap over an existing mmaping and effectively discarding
2772 // the existing pages. However it won't work for SHM-based large pages that cannot be
2773 // uncommitted at all. We don't do anything in this case to avoid creating a segment with
2774 // small pages on top of the SHM segment. This method always works for small pages, so we
2775 // allow that in any case.
2776 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) {
2777 commit_memory(addr, bytes, alignment_hint, !ExecMem);
2778 }
2779 }
2780
2781 void os::numa_make_global(char *addr, size_t bytes) {
2782 Linux::numa_interleave_memory(addr, bytes);
2783 }
2784
2785 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the
2786 // bind policy to MPOL_PREFERRED for the current thread.
2787 #define USE_MPOL_PREFERRED 0
2788
2789 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2790 // To make NUMA and large pages more robust when both enabled, we need to ease
2791 // the requirements on where the memory should be allocated. MPOL_BIND is the
2792 // default policy and it will force memory to be allocated on the specified
2793 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on
2794 // the specified node, but will not force it. Using this policy will prevent
2795 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no
2796 // free large pages.
2797 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED);
2798 Linux::numa_tonode_memory(addr, bytes, lgrp_hint);
2799 }
2800
2801 bool os::numa_topology_changed() { return false; }
2802
2803 size_t os::numa_get_groups_num() {
2804 // Return just the number of nodes in which it's possible to allocate memory
2805 // (in numa terminology, configured nodes).
2806 return Linux::numa_num_configured_nodes();
2807 }
2808
2809 int os::numa_get_group_id() {
2810 int cpu_id = Linux::sched_getcpu();
2811 if (cpu_id != -1) {
2812 int lgrp_id = Linux::get_node_by_cpu(cpu_id);
2813 if (lgrp_id != -1) {
2814 return lgrp_id;
2815 }
2816 }
2817 return 0;
2818 }
2819
2820 int os::Linux::get_existing_num_nodes() {
2821 int node;
2822 int highest_node_number = Linux::numa_max_node();
2823 int num_nodes = 0;
2824
2825 // Get the total number of nodes in the system including nodes without memory.
2826 for (node = 0; node <= highest_node_number; node++) {
2827 if (isnode_in_existing_nodes(node)) {
2828 num_nodes++;
2829 }
2830 }
2831 return num_nodes;
2832 }
2833
2834 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2835 int highest_node_number = Linux::numa_max_node();
2836 size_t i = 0;
2837
2838 // Map all node ids in which it is possible to allocate memory. Also nodes are
2839 // not always consecutively available, i.e. available from 0 to the highest
2840 // node number. If the nodes have been bound explicitly using numactl membind,
2841 // then allocate memory from those nodes only.
2842 for (int node = 0; node <= highest_node_number; node++) {
2843 if (Linux::isnode_in_bound_nodes((unsigned int)node)) {
2844 ids[i++] = node;
2845 }
2846 }
2847 return i;
2848 }
2849
2850 bool os::get_page_info(char *start, page_info* info) {
2851 return false;
2852 }
2853
2854 char *os::scan_pages(char *start, char* end, page_info* page_expected,
2855 page_info* page_found) {
2856 return end;
2857 }
2858
2859
2860 int os::Linux::sched_getcpu_syscall(void) {
2861 unsigned int cpu = 0;
2862 int retval = -1;
2863
2864 #if defined(IA32)
2865 #ifndef SYS_getcpu
2866 #define SYS_getcpu 318
2867 #endif
2868 retval = syscall(SYS_getcpu, &cpu, NULL, NULL);
2869 #elif defined(AMD64)
2870 // Unfortunately we have to bring all these macros here from vsyscall.h
2871 // to be able to compile on old linuxes.
2872 #define __NR_vgetcpu 2
2873 #define VSYSCALL_START (-10UL << 20)
2874 #define VSYSCALL_SIZE 1024
2875 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
2876 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache);
2877 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu);
2878 retval = vgetcpu(&cpu, NULL, NULL);
2879 #endif
2880
2881 return (retval == -1) ? retval : cpu;
2882 }
2883
2884 void os::Linux::sched_getcpu_init() {
2885 // sched_getcpu() should be in libc.
2886 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
2887 dlsym(RTLD_DEFAULT, "sched_getcpu")));
2888
2889 // If it's not, try a direct syscall.
2890 if (sched_getcpu() == -1) {
2891 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
2892 (void*)&sched_getcpu_syscall));
2893 }
2894
2895 if (sched_getcpu() == -1) {
2896 vm_exit_during_initialization("getcpu(2) system call not supported by kernel");
2897 }
2898 }
2899
2900 // Something to do with the numa-aware allocator needs these symbols
2901 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { }
2902 extern "C" JNIEXPORT void numa_error(char *where) { }
2903
2904 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails
2905 // load symbol from base version instead.
2906 void* os::Linux::libnuma_dlsym(void* handle, const char *name) {
2907 void *f = dlvsym(handle, name, "libnuma_1.1");
2908 if (f == NULL) {
2909 f = dlsym(handle, name);
2910 }
2911 return f;
2912 }
2913
2914 // Handle request to load libnuma symbol version 1.2 (API v2) only.
2915 // Return NULL if the symbol is not defined in this particular version.
2916 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) {
2917 return dlvsym(handle, name, "libnuma_1.2");
2918 }
2919
2920 bool os::Linux::libnuma_init() {
2921 if (sched_getcpu() != -1) { // Requires sched_getcpu() support
2922 void *handle = dlopen("libnuma.so.1", RTLD_LAZY);
2923 if (handle != NULL) {
2924 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t,
2925 libnuma_dlsym(handle, "numa_node_to_cpus")));
2926 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t,
2927 libnuma_dlsym(handle, "numa_max_node")));
2928 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t,
2929 libnuma_dlsym(handle, "numa_num_configured_nodes")));
2930 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t,
2931 libnuma_dlsym(handle, "numa_available")));
2932 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t,
2933 libnuma_dlsym(handle, "numa_tonode_memory")));
2934 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t,
2935 libnuma_dlsym(handle, "numa_interleave_memory")));
2936 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t,
2937 libnuma_v2_dlsym(handle, "numa_interleave_memory")));
2938 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t,
2939 libnuma_dlsym(handle, "numa_set_bind_policy")));
2940 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t,
2941 libnuma_dlsym(handle, "numa_bitmask_isbitset")));
2942 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t,
2943 libnuma_dlsym(handle, "numa_distance")));
2944 set_numa_get_membind(CAST_TO_FN_PTR(numa_get_membind_func_t,
2945 libnuma_v2_dlsym(handle, "numa_get_membind")));
2946
2947 if (numa_available() != -1) {
2948 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes"));
2949 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr"));
2950 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr"));
2951 // Create an index -> node mapping, since nodes are not always consecutive
2952 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
2953 rebuild_nindex_to_node_map();
2954 // Create a cpu -> node mapping
2955 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
2956 rebuild_cpu_to_node_map();
2957 return true;
2958 }
2959 }
2960 }
2961 return false;
2962 }
2963
2964 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
2965 // Creating guard page is very expensive. Java thread has HotSpot
2966 // guard pages, only enable glibc guard page for non-Java threads.
2967 // (Remember: compiler thread is a Java thread, too!)
2968 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size());
2969 }
2970
2971 void os::Linux::rebuild_nindex_to_node_map() {
2972 int highest_node_number = Linux::numa_max_node();
2973
2974 nindex_to_node()->clear();
2975 for (int node = 0; node <= highest_node_number; node++) {
2976 if (Linux::isnode_in_existing_nodes(node)) {
2977 nindex_to_node()->append(node);
2978 }
2979 }
2980 }
2981
2982 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id.
2983 // The table is later used in get_node_by_cpu().
2984 void os::Linux::rebuild_cpu_to_node_map() {
2985 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure
2986 // in libnuma (possible values are starting from 16,
2987 // and continuing up with every other power of 2, but less
2988 // than the maximum number of CPUs supported by kernel), and
2989 // is a subject to change (in libnuma version 2 the requirements
2990 // are more reasonable) we'll just hardcode the number they use
2991 // in the library.
2992 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT;
2993
2994 size_t cpu_num = processor_count();
2995 size_t cpu_map_size = NCPUS / BitsPerCLong;
2996 size_t cpu_map_valid_size =
2997 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size);
2998
2999 cpu_to_node()->clear();
3000 cpu_to_node()->at_grow(cpu_num - 1);
3001
3002 size_t node_num = get_existing_num_nodes();
3003
3004 int distance = 0;
3005 int closest_distance = INT_MAX;
3006 int closest_node = 0;
3007 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal);
3008 for (size_t i = 0; i < node_num; i++) {
3009 // Check if node is configured (not a memory-less node). If it is not, find
3010 // the closest configured node. Check also if node is bound, i.e. it's allowed
3011 // to allocate memory from the node. If it's not allowed, map cpus in that node
3012 // to the closest node from which memory allocation is allowed.
3013 if (!isnode_in_configured_nodes(nindex_to_node()->at(i)) ||
3014 !isnode_in_bound_nodes(nindex_to_node()->at(i))) {
3015 closest_distance = INT_MAX;
3016 // Check distance from all remaining nodes in the system. Ignore distance
3017 // from itself, from another non-configured node, and from another non-bound
3018 // node.
3019 for (size_t m = 0; m < node_num; m++) {
3020 if (m != i &&
3021 isnode_in_configured_nodes(nindex_to_node()->at(m)) &&
3022 isnode_in_bound_nodes(nindex_to_node()->at(m))) {
3023 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m));
3024 // If a closest node is found, update. There is always at least one
3025 // configured and bound node in the system so there is always at least
3026 // one node close.
3027 if (distance != 0 && distance < closest_distance) {
3028 closest_distance = distance;
3029 closest_node = nindex_to_node()->at(m);
3030 }
3031 }
3032 }
3033 } else {
3034 // Current node is already a configured node.
3035 closest_node = nindex_to_node()->at(i);
3036 }
3037
3038 // Get cpus from the original node and map them to the closest node. If node
3039 // is a configured node (not a memory-less node), then original node and
3040 // closest node are the same.
3041 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) {
3042 for (size_t j = 0; j < cpu_map_valid_size; j++) {
3043 if (cpu_map[j] != 0) {
3044 for (size_t k = 0; k < BitsPerCLong; k++) {
3045 if (cpu_map[j] & (1UL << k)) {
3046 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node);
3047 }
3048 }
3049 }
3050 }
3051 }
3052 }
3053 FREE_C_HEAP_ARRAY(unsigned long, cpu_map);
3054 }
3055
3056 int os::Linux::get_node_by_cpu(int cpu_id) {
3057 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) {
3058 return cpu_to_node()->at(cpu_id);
3059 }
3060 return -1;
3061 }
3062
3063 GrowableArray<int>* os::Linux::_cpu_to_node;
3064 GrowableArray<int>* os::Linux::_nindex_to_node;
3065 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu;
3066 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus;
3067 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node;
3068 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes;
3069 os::Linux::numa_available_func_t os::Linux::_numa_available;
3070 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory;
3071 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory;
3072 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2;
3073 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy;
3074 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset;
3075 os::Linux::numa_distance_func_t os::Linux::_numa_distance;
3076 os::Linux::numa_get_membind_func_t os::Linux::_numa_get_membind;
3077 unsigned long* os::Linux::_numa_all_nodes;
3078 struct bitmask* os::Linux::_numa_all_nodes_ptr;
3079 struct bitmask* os::Linux::_numa_nodes_ptr;
3080
3081 bool os::pd_uncommit_memory(char* addr, size_t size) {
3082 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
3083 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
3084 return res != (uintptr_t) MAP_FAILED;
3085 }
3086
3087 static address get_stack_commited_bottom(address bottom, size_t size) {
3088 address nbot = bottom;
3089 address ntop = bottom + size;
3090
3091 size_t page_sz = os::vm_page_size();
3092 unsigned pages = size / page_sz;
3093
3094 unsigned char vec[1];
3095 unsigned imin = 1, imax = pages + 1, imid;
3096 int mincore_return_value = 0;
3097
3098 assert(imin <= imax, "Unexpected page size");
3099
3100 while (imin < imax) {
3101 imid = (imax + imin) / 2;
3102 nbot = ntop - (imid * page_sz);
3103
3104 // Use a trick with mincore to check whether the page is mapped or not.
3105 // mincore sets vec to 1 if page resides in memory and to 0 if page
3106 // is swapped output but if page we are asking for is unmapped
3107 // it returns -1,ENOMEM
3108 mincore_return_value = mincore(nbot, page_sz, vec);
3109
3110 if (mincore_return_value == -1) {
3111 // Page is not mapped go up
3112 // to find first mapped page
3113 if (errno != EAGAIN) {
3114 assert(errno == ENOMEM, "Unexpected mincore errno");
3115 imax = imid;
3116 }
3117 } else {
3118 // Page is mapped go down
3119 // to find first not mapped page
3120 imin = imid + 1;
3121 }
3122 }
3123
3124 nbot = nbot + page_sz;
3125
3126 // Adjust stack bottom one page up if last checked page is not mapped
3127 if (mincore_return_value == -1) {
3128 nbot = nbot + page_sz;
3129 }
3130
3131 return nbot;
3132 }
3133
3134 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
3135 int mincore_return_value;
3136 const size_t stripe = 1024; // query this many pages each time
3137 unsigned char vec[stripe + 1];
3138 // set a guard
3139 vec[stripe] = 'X';
3140
3141 const size_t page_sz = os::vm_page_size();
3142 size_t pages = size / page_sz;
3143
3144 assert(is_aligned(start, page_sz), "Start address must be page aligned");
3145 assert(is_aligned(size, page_sz), "Size must be page aligned");
3146
3147 committed_start = NULL;
3148
3149 int loops = (pages + stripe - 1) / stripe;
3150 int committed_pages = 0;
3151 address loop_base = start;
3152 bool found_range = false;
3153
3154 for (int index = 0; index < loops && !found_range; index ++) {
3155 assert(pages > 0, "Nothing to do");
3156 int pages_to_query = (pages >= stripe) ? stripe : pages;
3157 pages -= pages_to_query;
3158
3159 // Get stable read
3160 while ((mincore_return_value = mincore(loop_base, pages_to_query * page_sz, vec)) == -1 && errno == EAGAIN);
3161
3162 // During shutdown, some memory goes away without properly notifying NMT,
3163 // E.g. ConcurrentGCThread/WatcherThread can exit without deleting thread object.
3164 // Bailout and return as not committed for now.
3165 if (mincore_return_value == -1 && errno == ENOMEM) {
3166 return false;
3167 }
3168
3169 assert(vec[stripe] == 'X', "overflow guard");
3170 assert(mincore_return_value == 0, "Range must be valid");
3171 // Process this stripe
3172 for (int vecIdx = 0; vecIdx < pages_to_query; vecIdx ++) {
3173 if ((vec[vecIdx] & 0x01) == 0) { // not committed
3174 // End of current contiguous region
3175 if (committed_start != NULL) {
3176 found_range = true;
3177 break;
3178 }
3179 } else { // committed
3180 // Start of region
3181 if (committed_start == NULL) {
3182 committed_start = loop_base + page_sz * vecIdx;
3183 }
3184 committed_pages ++;
3185 }
3186 }
3187
3188 loop_base += pages_to_query * page_sz;
3189 }
3190
3191 if (committed_start != NULL) {
3192 assert(committed_pages > 0, "Must have committed region");
3193 assert(committed_pages <= int(size / page_sz), "Can not commit more than it has");
3194 assert(committed_start >= start && committed_start < start + size, "Out of range");
3195 committed_size = page_sz * committed_pages;
3196 return true;
3197 } else {
3198 assert(committed_pages == 0, "Should not have committed region");
3199 return false;
3200 }
3201 }
3202
3203
3204 // Linux uses a growable mapping for the stack, and if the mapping for
3205 // the stack guard pages is not removed when we detach a thread the
3206 // stack cannot grow beyond the pages where the stack guard was
3207 // mapped. If at some point later in the process the stack expands to
3208 // that point, the Linux kernel cannot expand the stack any further
3209 // because the guard pages are in the way, and a segfault occurs.
3210 //
3211 // However, it's essential not to split the stack region by unmapping
3212 // a region (leaving a hole) that's already part of the stack mapping,
3213 // so if the stack mapping has already grown beyond the guard pages at
3214 // the time we create them, we have to truncate the stack mapping.
3215 // So, we need to know the extent of the stack mapping when
3216 // create_stack_guard_pages() is called.
3217
3218 // We only need this for stacks that are growable: at the time of
3219 // writing thread stacks don't use growable mappings (i.e. those
3220 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this
3221 // only applies to the main thread.
3222
3223 // If the (growable) stack mapping already extends beyond the point
3224 // where we're going to put our guard pages, truncate the mapping at
3225 // that point by munmap()ping it. This ensures that when we later
3226 // munmap() the guard pages we don't leave a hole in the stack
3227 // mapping. This only affects the main/primordial thread
3228
3229 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
3230 if (os::is_primordial_thread()) {
3231 // As we manually grow stack up to bottom inside create_attached_thread(),
3232 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and
3233 // we don't need to do anything special.
3234 // Check it first, before calling heavy function.
3235 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom();
3236 unsigned char vec[1];
3237
3238 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) {
3239 // Fallback to slow path on all errors, including EAGAIN
3240 stack_extent = (uintptr_t) get_stack_commited_bottom(
3241 os::Linux::initial_thread_stack_bottom(),
3242 (size_t)addr - stack_extent);
3243 }
3244
3245 if (stack_extent < (uintptr_t)addr) {
3246 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent));
3247 }
3248 }
3249
3250 return os::commit_memory(addr, size, !ExecMem);
3251 }
3252
3253 // If this is a growable mapping, remove the guard pages entirely by
3254 // munmap()ping them. If not, just call uncommit_memory(). This only
3255 // affects the main/primordial thread, but guard against future OS changes.
3256 // It's safe to always unmap guard pages for primordial thread because we
3257 // always place it right after end of the mapped region.
3258
3259 bool os::remove_stack_guard_pages(char* addr, size_t size) {
3260 uintptr_t stack_extent, stack_base;
3261
3262 if (os::is_primordial_thread()) {
3263 return ::munmap(addr, size) == 0;
3264 }
3265
3266 return os::uncommit_memory(addr, size);
3267 }
3268
3269 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
3270 // at 'requested_addr'. If there are existing memory mappings at the same
3271 // location, however, they will be overwritten. If 'fixed' is false,
3272 // 'requested_addr' is only treated as a hint, the return value may or
3273 // may not start from the requested address. Unlike Linux mmap(), this
3274 // function returns NULL to indicate failure.
3275 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
3276 char * addr;
3277 int flags;
3278
3279 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
3280 if (fixed) {
3281 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address");
3282 flags |= MAP_FIXED;
3283 }
3284
3285 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
3286 // touch an uncommitted page. Otherwise, the read/write might
3287 // succeed if we have enough swap space to back the physical page.
3288 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
3289 flags, -1, 0);
3290
3291 return addr == MAP_FAILED ? NULL : addr;
3292 }
3293
3294 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address
3295 // (req_addr != NULL) or with a given alignment.
3296 // - bytes shall be a multiple of alignment.
3297 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3298 // - alignment sets the alignment at which memory shall be allocated.
3299 // It must be a multiple of allocation granularity.
3300 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3301 // req_addr or NULL.
3302 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) {
3303
3304 size_t extra_size = bytes;
3305 if (req_addr == NULL && alignment > 0) {
3306 extra_size += alignment;
3307 }
3308
3309 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE,
3310 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
3311 -1, 0);
3312 if (start == MAP_FAILED) {
3313 start = NULL;
3314 } else {
3315 if (req_addr != NULL) {
3316 if (start != req_addr) {
3317 ::munmap(start, extra_size);
3318 start = NULL;
3319 }
3320 } else {
3321 char* const start_aligned = align_up(start, alignment);
3322 char* const end_aligned = start_aligned + bytes;
3323 char* const end = start + extra_size;
3324 if (start_aligned > start) {
3325 ::munmap(start, start_aligned - start);
3326 }
3327 if (end_aligned < end) {
3328 ::munmap(end_aligned, end - end_aligned);
3329 }
3330 start = start_aligned;
3331 }
3332 }
3333 return start;
3334 }
3335
3336 static int anon_munmap(char * addr, size_t size) {
3337 return ::munmap(addr, size) == 0;
3338 }
3339
3340 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
3341 size_t alignment_hint) {
3342 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
3343 }
3344
3345 bool os::pd_release_memory(char* addr, size_t size) {
3346 return anon_munmap(addr, size);
3347 }
3348
3349 static bool linux_mprotect(char* addr, size_t size, int prot) {
3350 // Linux wants the mprotect address argument to be page aligned.
3351 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size());
3352
3353 // According to SUSv3, mprotect() should only be used with mappings
3354 // established by mmap(), and mmap() always maps whole pages. Unaligned
3355 // 'addr' likely indicates problem in the VM (e.g. trying to change
3356 // protection of malloc'ed or statically allocated memory). Check the
3357 // caller if you hit this assert.
3358 assert(addr == bottom, "sanity check");
3359
3360 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size());
3361 return ::mprotect(bottom, size, prot) == 0;
3362 }
3363
3364 // Set protections specified
3365 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
3366 bool is_committed) {
3367 unsigned int p = 0;
3368 switch (prot) {
3369 case MEM_PROT_NONE: p = PROT_NONE; break;
3370 case MEM_PROT_READ: p = PROT_READ; break;
3371 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
3372 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
3373 default:
3374 ShouldNotReachHere();
3375 }
3376 // is_committed is unused.
3377 return linux_mprotect(addr, bytes, p);
3378 }
3379
3380 bool os::guard_memory(char* addr, size_t size) {
3381 return linux_mprotect(addr, size, PROT_NONE);
3382 }
3383
3384 bool os::unguard_memory(char* addr, size_t size) {
3385 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE);
3386 }
3387
3388 bool os::Linux::transparent_huge_pages_sanity_check(bool warn,
3389 size_t page_size) {
3390 bool result = false;
3391 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,
3392 MAP_ANONYMOUS|MAP_PRIVATE,
3393 -1, 0);
3394 if (p != MAP_FAILED) {
3395 void *aligned_p = align_up(p, page_size);
3396
3397 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0;
3398
3399 munmap(p, page_size * 2);
3400 }
3401
3402 if (warn && !result) {
3403 warning("TransparentHugePages is not supported by the operating system.");
3404 }
3405
3406 return result;
3407 }
3408
3409 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) {
3410 bool result = false;
3411 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
3412 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB,
3413 -1, 0);
3414
3415 if (p != MAP_FAILED) {
3416 // We don't know if this really is a huge page or not.
3417 FILE *fp = fopen("/proc/self/maps", "r");
3418 if (fp) {
3419 while (!feof(fp)) {
3420 char chars[257];
3421 long x = 0;
3422 if (fgets(chars, sizeof(chars), fp)) {
3423 if (sscanf(chars, "%lx-%*x", &x) == 1
3424 && x == (long)p) {
3425 if (strstr (chars, "hugepage")) {
3426 result = true;
3427 break;
3428 }
3429 }
3430 }
3431 }
3432 fclose(fp);
3433 }
3434 munmap(p, page_size);
3435 }
3436
3437 if (warn && !result) {
3438 warning("HugeTLBFS is not supported by the operating system.");
3439 }
3440
3441 return result;
3442 }
3443
3444 // Set the coredump_filter bits to include largepages in core dump (bit 6)
3445 //
3446 // From the coredump_filter documentation:
3447 //
3448 // - (bit 0) anonymous private memory
3449 // - (bit 1) anonymous shared memory
3450 // - (bit 2) file-backed private memory
3451 // - (bit 3) file-backed shared memory
3452 // - (bit 4) ELF header pages in file-backed private memory areas (it is
3453 // effective only if the bit 2 is cleared)
3454 // - (bit 5) hugetlb private memory
3455 // - (bit 6) hugetlb shared memory
3456 // - (bit 7) dax private memory
3457 // - (bit 8) dax shared memory
3458 //
3459 static void set_coredump_filter(bool largepages, bool dax_shared) {
3460 FILE *f;
3461 long cdm;
3462 bool filter_changed = false;
3463
3464 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
3465 return;
3466 }
3467
3468 if (fscanf(f, "%lx", &cdm) != 1) {
3469 fclose(f);
3470 return;
3471 }
3472
3473 rewind(f);
3474
3475 if (largepages && (cdm & LARGEPAGES_BIT) == 0) {
3476 cdm |= LARGEPAGES_BIT;
3477 filter_changed = true;
3478 }
3479 if (dax_shared && (cdm & DAX_SHARED_BIT) == 0) {
3480 cdm |= DAX_SHARED_BIT;
3481 filter_changed = true;
3482 }
3483 if (filter_changed) {
3484 fprintf(f, "%#lx", cdm);
3485 }
3486
3487 fclose(f);
3488 }
3489
3490 // Large page support
3491
3492 static size_t _large_page_size = 0;
3493
3494 size_t os::Linux::find_large_page_size() {
3495 size_t large_page_size = 0;
3496
3497 // large_page_size on Linux is used to round up heap size. x86 uses either
3498 // 2M or 4M page, depending on whether PAE (Physical Address Extensions)
3499 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use
3500 // page as large as 256M.
3501 //
3502 // Here we try to figure out page size by parsing /proc/meminfo and looking
3503 // for a line with the following format:
3504 // Hugepagesize: 2048 kB
3505 //
3506 // If we can't determine the value (e.g. /proc is not mounted, or the text
3507 // format has been changed), we'll use the largest page size supported by
3508 // the processor.
3509
3510 #ifndef ZERO
3511 large_page_size =
3512 AARCH64_ONLY(2 * M)
3513 AMD64_ONLY(2 * M)
3514 ARM32_ONLY(2 * M)
3515 IA32_ONLY(4 * M)
3516 IA64_ONLY(256 * M)
3517 PPC_ONLY(4 * M)
3518 S390_ONLY(1 * M)
3519 SPARC_ONLY(4 * M);
3520 #endif // ZERO
3521
3522 FILE *fp = fopen("/proc/meminfo", "r");
3523 if (fp) {
3524 while (!feof(fp)) {
3525 int x = 0;
3526 char buf[16];
3527 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) {
3528 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) {
3529 large_page_size = x * K;
3530 break;
3531 }
3532 } else {
3533 // skip to next line
3534 for (;;) {
3535 int ch = fgetc(fp);
3536 if (ch == EOF || ch == (int)'\n') break;
3537 }
3538 }
3539 }
3540 fclose(fp);
3541 }
3542
3543 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) {
3544 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is "
3545 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size),
3546 proper_unit_for_byte_size(large_page_size));
3547 }
3548
3549 return large_page_size;
3550 }
3551
3552 size_t os::Linux::setup_large_page_size() {
3553 _large_page_size = Linux::find_large_page_size();
3554 const size_t default_page_size = (size_t)Linux::page_size();
3555 if (_large_page_size > default_page_size) {
3556 _page_sizes[0] = _large_page_size;
3557 _page_sizes[1] = default_page_size;
3558 _page_sizes[2] = 0;
3559 }
3560
3561 return _large_page_size;
3562 }
3563
3564 bool os::Linux::setup_large_page_type(size_t page_size) {
3565 if (FLAG_IS_DEFAULT(UseHugeTLBFS) &&
3566 FLAG_IS_DEFAULT(UseSHM) &&
3567 FLAG_IS_DEFAULT(UseTransparentHugePages)) {
3568
3569 // The type of large pages has not been specified by the user.
3570
3571 // Try UseHugeTLBFS and then UseSHM.
3572 UseHugeTLBFS = UseSHM = true;
3573
3574 // Don't try UseTransparentHugePages since there are known
3575 // performance issues with it turned on. This might change in the future.
3576 UseTransparentHugePages = false;
3577 }
3578
3579 if (UseTransparentHugePages) {
3580 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages);
3581 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) {
3582 UseHugeTLBFS = false;
3583 UseSHM = false;
3584 return true;
3585 }
3586 UseTransparentHugePages = false;
3587 }
3588
3589 if (UseHugeTLBFS) {
3590 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS);
3591 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) {
3592 UseSHM = false;
3593 return true;
3594 }
3595 UseHugeTLBFS = false;
3596 }
3597
3598 return UseSHM;
3599 }
3600
3601 void os::large_page_init() {
3602 if (!UseLargePages &&
3603 !UseTransparentHugePages &&
3604 !UseHugeTLBFS &&
3605 !UseSHM) {
3606 // Not using large pages.
3607 return;
3608 }
3609
3610 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) {
3611 // The user explicitly turned off large pages.
3612 // Ignore the rest of the large pages flags.
3613 UseTransparentHugePages = false;
3614 UseHugeTLBFS = false;
3615 UseSHM = false;
3616 return;
3617 }
3618
3619 size_t large_page_size = Linux::setup_large_page_size();
3620 UseLargePages = Linux::setup_large_page_type(large_page_size);
3621
3622 set_coredump_filter(true /*largepages*/, false /*dax_shared*/);
3623 }
3624
3625 #ifndef SHM_HUGETLB
3626 #define SHM_HUGETLB 04000
3627 #endif
3628
3629 #define shm_warning_format(format, ...) \
3630 do { \
3631 if (UseLargePages && \
3632 (!FLAG_IS_DEFAULT(UseLargePages) || \
3633 !FLAG_IS_DEFAULT(UseSHM) || \
3634 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \
3635 warning(format, __VA_ARGS__); \
3636 } \
3637 } while (0)
3638
3639 #define shm_warning(str) shm_warning_format("%s", str)
3640
3641 #define shm_warning_with_errno(str) \
3642 do { \
3643 int err = errno; \
3644 shm_warning_format(str " (error = %d)", err); \
3645 } while (0)
3646
3647 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) {
3648 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment");
3649
3650 if (!is_aligned(alignment, SHMLBA)) {
3651 assert(false, "Code below assumes that alignment is at least SHMLBA aligned");
3652 return NULL;
3653 }
3654
3655 // To ensure that we get 'alignment' aligned memory from shmat,
3656 // we pre-reserve aligned virtual memory and then attach to that.
3657
3658 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL);
3659 if (pre_reserved_addr == NULL) {
3660 // Couldn't pre-reserve aligned memory.
3661 shm_warning("Failed to pre-reserve aligned memory for shmat.");
3662 return NULL;
3663 }
3664
3665 // SHM_REMAP is needed to allow shmat to map over an existing mapping.
3666 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP);
3667
3668 if ((intptr_t)addr == -1) {
3669 int err = errno;
3670 shm_warning_with_errno("Failed to attach shared memory.");
3671
3672 assert(err != EACCES, "Unexpected error");
3673 assert(err != EIDRM, "Unexpected error");
3674 assert(err != EINVAL, "Unexpected error");
3675
3676 // Since we don't know if the kernel unmapped the pre-reserved memory area
3677 // we can't unmap it, since that would potentially unmap memory that was
3678 // mapped from other threads.
3679 return NULL;
3680 }
3681
3682 return addr;
3683 }
3684
3685 static char* shmat_at_address(int shmid, char* req_addr) {
3686 if (!is_aligned(req_addr, SHMLBA)) {
3687 assert(false, "Requested address needs to be SHMLBA aligned");
3688 return NULL;
3689 }
3690
3691 char* addr = (char*)shmat(shmid, req_addr, 0);
3692
3693 if ((intptr_t)addr == -1) {
3694 shm_warning_with_errno("Failed to attach shared memory.");
3695 return NULL;
3696 }
3697
3698 return addr;
3699 }
3700
3701 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) {
3702 // If a req_addr has been provided, we assume that the caller has already aligned the address.
3703 if (req_addr != NULL) {
3704 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size");
3705 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment");
3706 return shmat_at_address(shmid, req_addr);
3707 }
3708
3709 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically
3710 // return large page size aligned memory addresses when req_addr == NULL.
3711 // However, if the alignment is larger than the large page size, we have
3712 // to manually ensure that the memory returned is 'alignment' aligned.
3713 if (alignment > os::large_page_size()) {
3714 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size");
3715 return shmat_with_alignment(shmid, bytes, alignment);
3716 } else {
3717 return shmat_at_address(shmid, NULL);
3718 }
3719 }
3720
3721 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment,
3722 char* req_addr, bool exec) {
3723 // "exec" is passed in but not used. Creating the shared image for
3724 // the code cache doesn't have an SHM_X executable permission to check.
3725 assert(UseLargePages && UseSHM, "only for SHM large pages");
3726 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
3727 assert(is_aligned(req_addr, alignment), "Unaligned address");
3728
3729 if (!is_aligned(bytes, os::large_page_size())) {
3730 return NULL; // Fallback to small pages.
3731 }
3732
3733 // Create a large shared memory region to attach to based on size.
3734 // Currently, size is the total size of the heap.
3735 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);
3736 if (shmid == -1) {
3737 // Possible reasons for shmget failure:
3738 // 1. shmmax is too small for Java heap.
3739 // > check shmmax value: cat /proc/sys/kernel/shmmax
3740 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
3741 // 2. not enough large page memory.
3742 // > check available large pages: cat /proc/meminfo
3743 // > increase amount of large pages:
3744 // echo new_value > /proc/sys/vm/nr_hugepages
3745 // Note 1: different Linux may use different name for this property,
3746 // e.g. on Redhat AS-3 it is "hugetlb_pool".
3747 // Note 2: it's possible there's enough physical memory available but
3748 // they are so fragmented after a long run that they can't
3749 // coalesce into large pages. Try to reserve large pages when
3750 // the system is still "fresh".
3751 shm_warning_with_errno("Failed to reserve shared memory.");
3752 return NULL;
3753 }
3754
3755 // Attach to the region.
3756 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr);
3757
3758 // Remove shmid. If shmat() is successful, the actual shared memory segment
3759 // will be deleted when it's detached by shmdt() or when the process
3760 // terminates. If shmat() is not successful this will remove the shared
3761 // segment immediately.
3762 shmctl(shmid, IPC_RMID, NULL);
3763
3764 return addr;
3765 }
3766
3767 static void warn_on_large_pages_failure(char* req_addr, size_t bytes,
3768 int error) {
3769 assert(error == ENOMEM, "Only expect to fail if no memory is available");
3770
3771 bool warn_on_failure = UseLargePages &&
3772 (!FLAG_IS_DEFAULT(UseLargePages) ||
3773 !FLAG_IS_DEFAULT(UseHugeTLBFS) ||
3774 !FLAG_IS_DEFAULT(LargePageSizeInBytes));
3775
3776 if (warn_on_failure) {
3777 char msg[128];
3778 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: "
3779 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error);
3780 warning("%s", msg);
3781 }
3782 }
3783
3784 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes,
3785 char* req_addr,
3786 bool exec) {
3787 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
3788 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size");
3789 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
3790
3791 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
3792 char* addr = (char*)::mmap(req_addr, bytes, prot,
3793 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB,
3794 -1, 0);
3795
3796 if (addr == MAP_FAILED) {
3797 warn_on_large_pages_failure(req_addr, bytes, errno);
3798 return NULL;
3799 }
3800
3801 assert(is_aligned(addr, os::large_page_size()), "Must be");
3802
3803 return addr;
3804 }
3805
3806 // Reserve memory using mmap(MAP_HUGETLB).
3807 // - bytes shall be a multiple of alignment.
3808 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3809 // - alignment sets the alignment at which memory shall be allocated.
3810 // It must be a multiple of allocation granularity.
3811 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3812 // req_addr or NULL.
3813 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes,
3814 size_t alignment,
3815 char* req_addr,
3816 bool exec) {
3817 size_t large_page_size = os::large_page_size();
3818 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes");
3819
3820 assert(is_aligned(req_addr, alignment), "Must be");
3821 assert(is_aligned(bytes, alignment), "Must be");
3822
3823 // First reserve - but not commit - the address range in small pages.
3824 char* const start = anon_mmap_aligned(bytes, alignment, req_addr);
3825
3826 if (start == NULL) {
3827 return NULL;
3828 }
3829
3830 assert(is_aligned(start, alignment), "Must be");
3831
3832 char* end = start + bytes;
3833
3834 // Find the regions of the allocated chunk that can be promoted to large pages.
3835 char* lp_start = align_up(start, large_page_size);
3836 char* lp_end = align_down(end, large_page_size);
3837
3838 size_t lp_bytes = lp_end - lp_start;
3839
3840 assert(is_aligned(lp_bytes, large_page_size), "Must be");
3841
3842 if (lp_bytes == 0) {
3843 // The mapped region doesn't even span the start and the end of a large page.
3844 // Fall back to allocate a non-special area.
3845 ::munmap(start, end - start);
3846 return NULL;
3847 }
3848
3849 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
3850
3851 void* result;
3852
3853 // Commit small-paged leading area.
3854 if (start != lp_start) {
3855 result = ::mmap(start, lp_start - start, prot,
3856 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
3857 -1, 0);
3858 if (result == MAP_FAILED) {
3859 ::munmap(lp_start, end - lp_start);
3860 return NULL;
3861 }
3862 }
3863
3864 // Commit large-paged area.
3865 result = ::mmap(lp_start, lp_bytes, prot,
3866 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB,
3867 -1, 0);
3868 if (result == MAP_FAILED) {
3869 warn_on_large_pages_failure(lp_start, lp_bytes, errno);
3870 // If the mmap above fails, the large pages region will be unmapped and we
3871 // have regions before and after with small pages. Release these regions.
3872 //
3873 // | mapped | unmapped | mapped |
3874 // ^ ^ ^ ^
3875 // start lp_start lp_end end
3876 //
3877 ::munmap(start, lp_start - start);
3878 ::munmap(lp_end, end - lp_end);
3879 return NULL;
3880 }
3881
3882 // Commit small-paged trailing area.
3883 if (lp_end != end) {
3884 result = ::mmap(lp_end, end - lp_end, prot,
3885 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
3886 -1, 0);
3887 if (result == MAP_FAILED) {
3888 ::munmap(start, lp_end - start);
3889 return NULL;
3890 }
3891 }
3892
3893 return start;
3894 }
3895
3896 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes,
3897 size_t alignment,
3898 char* req_addr,
3899 bool exec) {
3900 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
3901 assert(is_aligned(req_addr, alignment), "Must be");
3902 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be");
3903 assert(is_power_of_2(os::large_page_size()), "Must be");
3904 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes");
3905
3906 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) {
3907 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec);
3908 } else {
3909 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec);
3910 }
3911 }
3912
3913 char* os::reserve_memory_special(size_t bytes, size_t alignment,
3914 char* req_addr, bool exec) {
3915 assert(UseLargePages, "only for large pages");
3916
3917 char* addr;
3918 if (UseSHM) {
3919 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec);
3920 } else {
3921 assert(UseHugeTLBFS, "must be");
3922 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec);
3923 }
3924
3925 if (addr != NULL) {
3926 if (UseNUMAInterleaving) {
3927 numa_make_global(addr, bytes);
3928 }
3929
3930 // The memory is committed
3931 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
3932 }
3933
3934 return addr;
3935 }
3936
3937 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) {
3938 // detaching the SHM segment will also delete it, see reserve_memory_special_shm()
3939 return shmdt(base) == 0;
3940 }
3941
3942 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) {
3943 return pd_release_memory(base, bytes);
3944 }
3945
3946 bool os::release_memory_special(char* base, size_t bytes) {
3947 bool res;
3948 if (MemTracker::tracking_level() > NMT_minimal) {
3949 Tracker tkr(Tracker::release);
3950 res = os::Linux::release_memory_special_impl(base, bytes);
3951 if (res) {
3952 tkr.record((address)base, bytes);
3953 }
3954
3955 } else {
3956 res = os::Linux::release_memory_special_impl(base, bytes);
3957 }
3958 return res;
3959 }
3960
3961 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) {
3962 assert(UseLargePages, "only for large pages");
3963 bool res;
3964
3965 if (UseSHM) {
3966 res = os::Linux::release_memory_special_shm(base, bytes);
3967 } else {
3968 assert(UseHugeTLBFS, "must be");
3969 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes);
3970 }
3971 return res;
3972 }
3973
3974 size_t os::large_page_size() {
3975 return _large_page_size;
3976 }
3977
3978 // With SysV SHM the entire memory region must be allocated as shared
3979 // memory.
3980 // HugeTLBFS allows application to commit large page memory on demand.
3981 // However, when committing memory with HugeTLBFS fails, the region
3982 // that was supposed to be committed will lose the old reservation
3983 // and allow other threads to steal that memory region. Because of this
3984 // behavior we can't commit HugeTLBFS memory.
3985 bool os::can_commit_large_page_memory() {
3986 return UseTransparentHugePages;
3987 }
3988
3989 bool os::can_execute_large_page_memory() {
3990 return UseTransparentHugePages || UseHugeTLBFS;
3991 }
3992
3993 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
3994 assert(file_desc >= 0, "file_desc is not valid");
3995 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
3996 if (result != NULL) {
3997 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
3998 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
3999 }
4000 }
4001 return result;
4002 }
4003
4004 // Reserve memory at an arbitrary address, only if that area is
4005 // available (and not reserved for something else).
4006
4007 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
4008 const int max_tries = 10;
4009 char* base[max_tries];
4010 size_t size[max_tries];
4011 const size_t gap = 0x000000;
4012
4013 // Assert only that the size is a multiple of the page size, since
4014 // that's all that mmap requires, and since that's all we really know
4015 // about at this low abstraction level. If we need higher alignment,
4016 // we can either pass an alignment to this method or verify alignment
4017 // in one of the methods further up the call chain. See bug 5044738.
4018 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
4019
4020 // Repeatedly allocate blocks until the block is allocated at the
4021 // right spot.
4022
4023 // Linux mmap allows caller to pass an address as hint; give it a try first,
4024 // if kernel honors the hint then we can return immediately.
4025 char * addr = anon_mmap(requested_addr, bytes, false);
4026 if (addr == requested_addr) {
4027 return requested_addr;
4028 }
4029
4030 if (addr != NULL) {
4031 // mmap() is successful but it fails to reserve at the requested address
4032 anon_munmap(addr, bytes);
4033 }
4034
4035 int i;
4036 for (i = 0; i < max_tries; ++i) {
4037 base[i] = reserve_memory(bytes);
4038
4039 if (base[i] != NULL) {
4040 // Is this the block we wanted?
4041 if (base[i] == requested_addr) {
4042 size[i] = bytes;
4043 break;
4044 }
4045
4046 // Does this overlap the block we wanted? Give back the overlapped
4047 // parts and try again.
4048
4049 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i];
4050 if (top_overlap >= 0 && (size_t)top_overlap < bytes) {
4051 unmap_memory(base[i], top_overlap);
4052 base[i] += top_overlap;
4053 size[i] = bytes - top_overlap;
4054 } else {
4055 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr;
4056 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) {
4057 unmap_memory(requested_addr, bottom_overlap);
4058 size[i] = bytes - bottom_overlap;
4059 } else {
4060 size[i] = bytes;
4061 }
4062 }
4063 }
4064 }
4065
4066 // Give back the unused reserved pieces.
4067
4068 for (int j = 0; j < i; ++j) {
4069 if (base[j] != NULL) {
4070 unmap_memory(base[j], size[j]);
4071 }
4072 }
4073
4074 if (i < max_tries) {
4075 return requested_addr;
4076 } else {
4077 return NULL;
4078 }
4079 }
4080
4081 size_t os::read(int fd, void *buf, unsigned int nBytes) {
4082 return ::read(fd, buf, nBytes);
4083 }
4084
4085 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
4086 return ::pread(fd, buf, nBytes, offset);
4087 }
4088
4089 // Short sleep, direct OS call.
4090 //
4091 // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee
4092 // sched_yield(2) will actually give up the CPU:
4093 //
4094 // * Alone on this pariticular CPU, keeps running.
4095 // * Before the introduction of "skip_buddy" with "compat_yield" disabled
4096 // (pre 2.6.39).
4097 //
4098 // So calling this with 0 is an alternative.
4099 //
4100 void os::naked_short_sleep(jlong ms) {
4101 struct timespec req;
4102
4103 assert(ms < 1000, "Un-interruptable sleep, short time use only");
4104 req.tv_sec = 0;
4105 if (ms > 0) {
4106 req.tv_nsec = (ms % 1000) * 1000000;
4107 } else {
4108 req.tv_nsec = 1;
4109 }
4110
4111 nanosleep(&req, NULL);
4112
4113 return;
4114 }
4115
4116 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
4117 void os::infinite_sleep() {
4118 while (true) { // sleep forever ...
4119 ::sleep(100); // ... 100 seconds at a time
4120 }
4121 }
4122
4123 // Used to convert frequent JVM_Yield() to nops
4124 bool os::dont_yield() {
4125 return DontYieldALot;
4126 }
4127
4128 void os::naked_yield() {
4129 sched_yield();
4130 }
4131
4132 ////////////////////////////////////////////////////////////////////////////////
4133 // thread priority support
4134
4135 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER
4136 // only supports dynamic priority, static priority must be zero. For real-time
4137 // applications, Linux supports SCHED_RR which allows static priority (1-99).
4138 // However, for large multi-threaded applications, SCHED_RR is not only slower
4139 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
4140 // of 5 runs - Sep 2005).
4141 //
4142 // The following code actually changes the niceness of kernel-thread/LWP. It
4143 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
4144 // not the entire user process, and user level threads are 1:1 mapped to kernel
4145 // threads. It has always been the case, but could change in the future. For
4146 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
4147 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
4148
4149 int os::java_to_os_priority[CriticalPriority + 1] = {
4150 19, // 0 Entry should never be used
4151
4152 4, // 1 MinPriority
4153 3, // 2
4154 2, // 3
4155
4156 1, // 4
4157 0, // 5 NormPriority
4158 -1, // 6
4159
4160 -2, // 7
4161 -3, // 8
4162 -4, // 9 NearMaxPriority
4163
4164 -5, // 10 MaxPriority
4165
4166 -5 // 11 CriticalPriority
4167 };
4168
4169 static int prio_init() {
4170 if (ThreadPriorityPolicy == 1) {
4171 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
4172 // if effective uid is not root. Perhaps, a more elegant way of doing
4173 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
4174 if (geteuid() != 0) {
4175 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
4176 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux");
4177 }
4178 ThreadPriorityPolicy = 0;
4179 }
4180 }
4181 if (UseCriticalJavaThreadPriority) {
4182 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
4183 }
4184 return 0;
4185 }
4186
4187 OSReturn os::set_native_priority(Thread* thread, int newpri) {
4188 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
4189
4190 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
4191 return (ret == 0) ? OS_OK : OS_ERR;
4192 }
4193
4194 OSReturn os::get_native_priority(const Thread* const thread,
4195 int *priority_ptr) {
4196 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
4197 *priority_ptr = java_to_os_priority[NormPriority];
4198 return OS_OK;
4199 }
4200
4201 errno = 0;
4202 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
4203 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
4204 }
4205
4206 ////////////////////////////////////////////////////////////////////////////////
4207 // suspend/resume support
4208
4209 // The low-level signal-based suspend/resume support is a remnant from the
4210 // old VM-suspension that used to be for java-suspension, safepoints etc,
4211 // within hotspot. Currently used by JFR's OSThreadSampler
4212 //
4213 // The remaining code is greatly simplified from the more general suspension
4214 // code that used to be used.
4215 //
4216 // The protocol is quite simple:
4217 // - suspend:
4218 // - sends a signal to the target thread
4219 // - polls the suspend state of the osthread using a yield loop
4220 // - target thread signal handler (SR_handler) sets suspend state
4221 // and blocks in sigsuspend until continued
4222 // - resume:
4223 // - sets target osthread state to continue
4224 // - sends signal to end the sigsuspend loop in the SR_handler
4225 //
4226 // Note that the SR_lock plays no role in this suspend/resume protocol,
4227 // but is checked for NULL in SR_handler as a thread termination indicator.
4228 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
4229 //
4230 // Note that resume_clear_context() and suspend_save_context() are needed
4231 // by SR_handler(), so that fetch_frame_from_ucontext() works,
4232 // which in part is used by:
4233 // - Forte Analyzer: AsyncGetCallTrace()
4234 // - StackBanging: get_frame_at_stack_banging_point()
4235
4236 static void resume_clear_context(OSThread *osthread) {
4237 osthread->set_ucontext(NULL);
4238 osthread->set_siginfo(NULL);
4239 }
4240
4241 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo,
4242 ucontext_t* context) {
4243 osthread->set_ucontext(context);
4244 osthread->set_siginfo(siginfo);
4245 }
4246
4247 // Handler function invoked when a thread's execution is suspended or
4248 // resumed. We have to be careful that only async-safe functions are
4249 // called here (Note: most pthread functions are not async safe and
4250 // should be avoided.)
4251 //
4252 // Note: sigwait() is a more natural fit than sigsuspend() from an
4253 // interface point of view, but sigwait() prevents the signal hander
4254 // from being run. libpthread would get very confused by not having
4255 // its signal handlers run and prevents sigwait()'s use with the
4256 // mutex granting granting signal.
4257 //
4258 // Currently only ever called on the VMThread and JavaThreads (PC sampling)
4259 //
4260 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
4261 // Save and restore errno to avoid confusing native code with EINTR
4262 // after sigsuspend.
4263 int old_errno = errno;
4264
4265 Thread* thread = Thread::current_or_null_safe();
4266 assert(thread != NULL, "Missing current thread in SR_handler");
4267
4268 // On some systems we have seen signal delivery get "stuck" until the signal
4269 // mask is changed as part of thread termination. Check that the current thread
4270 // has not already terminated (via SR_lock()) - else the following assertion
4271 // will fail because the thread is no longer a JavaThread as the ~JavaThread
4272 // destructor has completed.
4273
4274 if (thread->SR_lock() == NULL) {
4275 return;
4276 }
4277
4278 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
4279
4280 OSThread* osthread = thread->osthread();
4281
4282 os::SuspendResume::State current = osthread->sr.state();
4283 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
4284 suspend_save_context(osthread, siginfo, context);
4285
4286 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
4287 os::SuspendResume::State state = osthread->sr.suspended();
4288 if (state == os::SuspendResume::SR_SUSPENDED) {
4289 sigset_t suspend_set; // signals for sigsuspend()
4290 sigemptyset(&suspend_set);
4291 // get current set of blocked signals and unblock resume signal
4292 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
4293 sigdelset(&suspend_set, SR_signum);
4294
4295 sr_semaphore.signal();
4296 // wait here until we are resumed
4297 while (1) {
4298 sigsuspend(&suspend_set);
4299
4300 os::SuspendResume::State result = osthread->sr.running();
4301 if (result == os::SuspendResume::SR_RUNNING) {
4302 sr_semaphore.signal();
4303 break;
4304 }
4305 }
4306
4307 } else if (state == os::SuspendResume::SR_RUNNING) {
4308 // request was cancelled, continue
4309 } else {
4310 ShouldNotReachHere();
4311 }
4312
4313 resume_clear_context(osthread);
4314 } else if (current == os::SuspendResume::SR_RUNNING) {
4315 // request was cancelled, continue
4316 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
4317 // ignore
4318 } else {
4319 // ignore
4320 }
4321
4322 errno = old_errno;
4323 }
4324
4325 static int SR_initialize() {
4326 struct sigaction act;
4327 char *s;
4328
4329 // Get signal number to use for suspend/resume
4330 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
4331 int sig = ::strtol(s, 0, 10);
4332 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769.
4333 sig < NSIG) { // Must be legal signal and fit into sigflags[].
4334 SR_signum = sig;
4335 } else {
4336 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
4337 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
4338 }
4339 }
4340
4341 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
4342 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
4343
4344 sigemptyset(&SR_sigset);
4345 sigaddset(&SR_sigset, SR_signum);
4346
4347 // Set up signal handler for suspend/resume
4348 act.sa_flags = SA_RESTART|SA_SIGINFO;
4349 act.sa_handler = (void (*)(int)) SR_handler;
4350
4351 // SR_signum is blocked by default.
4352 // 4528190 - We also need to block pthread restart signal (32 on all
4353 // supported Linux platforms). Note that LinuxThreads need to block
4354 // this signal for all threads to work properly. So we don't have
4355 // to use hard-coded signal number when setting up the mask.
4356 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
4357
4358 if (sigaction(SR_signum, &act, 0) == -1) {
4359 return -1;
4360 }
4361
4362 // Save signal flag
4363 os::Linux::set_our_sigflags(SR_signum, act.sa_flags);
4364 return 0;
4365 }
4366
4367 static int sr_notify(OSThread* osthread) {
4368 int status = pthread_kill(osthread->pthread_id(), SR_signum);
4369 assert_status(status == 0, status, "pthread_kill");
4370 return status;
4371 }
4372
4373 // "Randomly" selected value for how long we want to spin
4374 // before bailing out on suspending a thread, also how often
4375 // we send a signal to a thread we want to resume
4376 static const int RANDOMLY_LARGE_INTEGER = 1000000;
4377 static const int RANDOMLY_LARGE_INTEGER2 = 100;
4378
4379 // returns true on success and false on error - really an error is fatal
4380 // but this seems the normal response to library errors
4381 static bool do_suspend(OSThread* osthread) {
4382 assert(osthread->sr.is_running(), "thread should be running");
4383 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
4384
4385 // mark as suspended and send signal
4386 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
4387 // failed to switch, state wasn't running?
4388 ShouldNotReachHere();
4389 return false;
4390 }
4391
4392 if (sr_notify(osthread) != 0) {
4393 ShouldNotReachHere();
4394 }
4395
4396 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
4397 while (true) {
4398 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) {
4399 break;
4400 } else {
4401 // timeout
4402 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
4403 if (cancelled == os::SuspendResume::SR_RUNNING) {
4404 return false;
4405 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
4406 // make sure that we consume the signal on the semaphore as well
4407 sr_semaphore.wait();
4408 break;
4409 } else {
4410 ShouldNotReachHere();
4411 return false;
4412 }
4413 }
4414 }
4415
4416 guarantee(osthread->sr.is_suspended(), "Must be suspended");
4417 return true;
4418 }
4419
4420 static void do_resume(OSThread* osthread) {
4421 assert(osthread->sr.is_suspended(), "thread should be suspended");
4422 assert(!sr_semaphore.trywait(), "invalid semaphore state");
4423
4424 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
4425 // failed to switch to WAKEUP_REQUEST
4426 ShouldNotReachHere();
4427 return;
4428 }
4429
4430 while (true) {
4431 if (sr_notify(osthread) == 0) {
4432 if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) {
4433 if (osthread->sr.is_running()) {
4434 return;
4435 }
4436 }
4437 } else {
4438 ShouldNotReachHere();
4439 }
4440 }
4441
4442 guarantee(osthread->sr.is_running(), "Must be running!");
4443 }
4444
4445 ///////////////////////////////////////////////////////////////////////////////////
4446 // signal handling (except suspend/resume)
4447
4448 // This routine may be used by user applications as a "hook" to catch signals.
4449 // The user-defined signal handler must pass unrecognized signals to this
4450 // routine, and if it returns true (non-zero), then the signal handler must
4451 // return immediately. If the flag "abort_if_unrecognized" is true, then this
4452 // routine will never retun false (zero), but instead will execute a VM panic
4453 // routine kill the process.
4454 //
4455 // If this routine returns false, it is OK to call it again. This allows
4456 // the user-defined signal handler to perform checks either before or after
4457 // the VM performs its own checks. Naturally, the user code would be making
4458 // a serious error if it tried to handle an exception (such as a null check
4459 // or breakpoint) that the VM was generating for its own correct operation.
4460 //
4461 // This routine may recognize any of the following kinds of signals:
4462 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
4463 // It should be consulted by handlers for any of those signals.
4464 //
4465 // The caller of this routine must pass in the three arguments supplied
4466 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
4467 // field of the structure passed to sigaction(). This routine assumes that
4468 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
4469 //
4470 // Note that the VM will print warnings if it detects conflicting signal
4471 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
4472 //
4473 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo,
4474 siginfo_t* siginfo,
4475 void* ucontext,
4476 int abort_if_unrecognized);
4477
4478 static void signalHandler(int sig, siginfo_t* info, void* uc) {
4479 assert(info != NULL && uc != NULL, "it must be old kernel");
4480 int orig_errno = errno; // Preserve errno value over signal handler.
4481 JVM_handle_linux_signal(sig, info, uc, true);
4482 errno = orig_errno;
4483 }
4484
4485
4486 // This boolean allows users to forward their own non-matching signals
4487 // to JVM_handle_linux_signal, harmlessly.
4488 bool os::Linux::signal_handlers_are_installed = false;
4489
4490 // For signal-chaining
4491 struct sigaction sigact[NSIG];
4492 uint64_t sigs = 0;
4493 #if (64 < NSIG-1)
4494 #error "Not all signals can be encoded in sigs. Adapt its type!"
4495 #endif
4496 bool os::Linux::libjsig_is_loaded = false;
4497 typedef struct sigaction *(*get_signal_t)(int);
4498 get_signal_t os::Linux::get_signal_action = NULL;
4499
4500 struct sigaction* os::Linux::get_chained_signal_action(int sig) {
4501 struct sigaction *actp = NULL;
4502
4503 if (libjsig_is_loaded) {
4504 // Retrieve the old signal handler from libjsig
4505 actp = (*get_signal_action)(sig);
4506 }
4507 if (actp == NULL) {
4508 // Retrieve the preinstalled signal handler from jvm
4509 actp = get_preinstalled_handler(sig);
4510 }
4511
4512 return actp;
4513 }
4514
4515 static bool call_chained_handler(struct sigaction *actp, int sig,
4516 siginfo_t *siginfo, void *context) {
4517 // Call the old signal handler
4518 if (actp->sa_handler == SIG_DFL) {
4519 // It's more reasonable to let jvm treat it as an unexpected exception
4520 // instead of taking the default action.
4521 return false;
4522 } else if (actp->sa_handler != SIG_IGN) {
4523 if ((actp->sa_flags & SA_NODEFER) == 0) {
4524 // automaticlly block the signal
4525 sigaddset(&(actp->sa_mask), sig);
4526 }
4527
4528 sa_handler_t hand = NULL;
4529 sa_sigaction_t sa = NULL;
4530 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
4531 // retrieve the chained handler
4532 if (siginfo_flag_set) {
4533 sa = actp->sa_sigaction;
4534 } else {
4535 hand = actp->sa_handler;
4536 }
4537
4538 if ((actp->sa_flags & SA_RESETHAND) != 0) {
4539 actp->sa_handler = SIG_DFL;
4540 }
4541
4542 // try to honor the signal mask
4543 sigset_t oset;
4544 sigemptyset(&oset);
4545 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
4546
4547 // call into the chained handler
4548 if (siginfo_flag_set) {
4549 (*sa)(sig, siginfo, context);
4550 } else {
4551 (*hand)(sig);
4552 }
4553
4554 // restore the signal mask
4555 pthread_sigmask(SIG_SETMASK, &oset, NULL);
4556 }
4557 // Tell jvm's signal handler the signal is taken care of.
4558 return true;
4559 }
4560
4561 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) {
4562 bool chained = false;
4563 // signal-chaining
4564 if (UseSignalChaining) {
4565 struct sigaction *actp = get_chained_signal_action(sig);
4566 if (actp != NULL) {
4567 chained = call_chained_handler(actp, sig, siginfo, context);
4568 }
4569 }
4570 return chained;
4571 }
4572
4573 struct sigaction* os::Linux::get_preinstalled_handler(int sig) {
4574 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) {
4575 return &sigact[sig];
4576 }
4577 return NULL;
4578 }
4579
4580 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
4581 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4582 sigact[sig] = oldAct;
4583 sigs |= (uint64_t)1 << (sig-1);
4584 }
4585
4586 // for diagnostic
4587 int sigflags[NSIG];
4588
4589 int os::Linux::get_our_sigflags(int sig) {
4590 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4591 return sigflags[sig];
4592 }
4593
4594 void os::Linux::set_our_sigflags(int sig, int flags) {
4595 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4596 if (sig > 0 && sig < NSIG) {
4597 sigflags[sig] = flags;
4598 }
4599 }
4600
4601 void os::Linux::set_signal_handler(int sig, bool set_installed) {
4602 // Check for overwrite.
4603 struct sigaction oldAct;
4604 sigaction(sig, (struct sigaction*)NULL, &oldAct);
4605
4606 void* oldhand = oldAct.sa_sigaction
4607 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4608 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4609 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
4610 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
4611 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
4612 if (AllowUserSignalHandlers || !set_installed) {
4613 // Do not overwrite; user takes responsibility to forward to us.
4614 return;
4615 } else if (UseSignalChaining) {
4616 // save the old handler in jvm
4617 save_preinstalled_handler(sig, oldAct);
4618 // libjsig also interposes the sigaction() call below and saves the
4619 // old sigaction on it own.
4620 } else {
4621 fatal("Encountered unexpected pre-existing sigaction handler "
4622 "%#lx for signal %d.", (long)oldhand, sig);
4623 }
4624 }
4625
4626 struct sigaction sigAct;
4627 sigfillset(&(sigAct.sa_mask));
4628 sigAct.sa_handler = SIG_DFL;
4629 if (!set_installed) {
4630 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4631 } else {
4632 sigAct.sa_sigaction = signalHandler;
4633 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4634 }
4635 // Save flags, which are set by ours
4636 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4637 sigflags[sig] = sigAct.sa_flags;
4638
4639 int ret = sigaction(sig, &sigAct, &oldAct);
4640 assert(ret == 0, "check");
4641
4642 void* oldhand2 = oldAct.sa_sigaction
4643 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4644 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4645 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
4646 }
4647
4648 // install signal handlers for signals that HotSpot needs to
4649 // handle in order to support Java-level exception handling.
4650
4651 void os::Linux::install_signal_handlers() {
4652 if (!signal_handlers_are_installed) {
4653 signal_handlers_are_installed = true;
4654
4655 // signal-chaining
4656 typedef void (*signal_setting_t)();
4657 signal_setting_t begin_signal_setting = NULL;
4658 signal_setting_t end_signal_setting = NULL;
4659 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4660 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
4661 if (begin_signal_setting != NULL) {
4662 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4663 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
4664 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
4665 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
4666 libjsig_is_loaded = true;
4667 assert(UseSignalChaining, "should enable signal-chaining");
4668 }
4669 if (libjsig_is_loaded) {
4670 // Tell libjsig jvm is setting signal handlers
4671 (*begin_signal_setting)();
4672 }
4673
4674 set_signal_handler(SIGSEGV, true);
4675 set_signal_handler(SIGPIPE, true);
4676 set_signal_handler(SIGBUS, true);
4677 set_signal_handler(SIGILL, true);
4678 set_signal_handler(SIGFPE, true);
4679 #if defined(PPC64)
4680 set_signal_handler(SIGTRAP, true);
4681 #endif
4682 set_signal_handler(SIGXFSZ, true);
4683
4684 if (libjsig_is_loaded) {
4685 // Tell libjsig jvm finishes setting signal handlers
4686 (*end_signal_setting)();
4687 }
4688
4689 // We don't activate signal checker if libjsig is in place, we trust ourselves
4690 // and if UserSignalHandler is installed all bets are off.
4691 // Log that signal checking is off only if -verbose:jni is specified.
4692 if (CheckJNICalls) {
4693 if (libjsig_is_loaded) {
4694 if (PrintJNIResolving) {
4695 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
4696 }
4697 check_signals = false;
4698 }
4699 if (AllowUserSignalHandlers) {
4700 if (PrintJNIResolving) {
4701 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
4702 }
4703 check_signals = false;
4704 }
4705 }
4706 }
4707 }
4708
4709 // This is the fastest way to get thread cpu time on Linux.
4710 // Returns cpu time (user+sys) for any thread, not only for current.
4711 // POSIX compliant clocks are implemented in the kernels 2.6.16+.
4712 // It might work on 2.6.10+ with a special kernel/glibc patch.
4713 // For reference, please, see IEEE Std 1003.1-2004:
4714 // http://www.unix.org/single_unix_specification
4715
4716 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) {
4717 struct timespec tp;
4718 int rc = os::Linux::clock_gettime(clockid, &tp);
4719 assert(rc == 0, "clock_gettime is expected to return 0 code");
4720
4721 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec;
4722 }
4723
4724 void os::Linux::initialize_os_info() {
4725 assert(_os_version == 0, "OS info already initialized");
4726
4727 struct utsname _uname;
4728
4729 uint32_t major;
4730 uint32_t minor;
4731 uint32_t fix;
4732
4733 int rc;
4734
4735 // Kernel version is unknown if
4736 // verification below fails.
4737 _os_version = 0x01000000;
4738
4739 rc = uname(&_uname);
4740 if (rc != -1) {
4741
4742 rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix);
4743 if (rc == 3) {
4744
4745 if (major < 256 && minor < 256 && fix < 256) {
4746 // Kernel version format is as expected,
4747 // set it overriding unknown state.
4748 _os_version = (major << 16) |
4749 (minor << 8 ) |
4750 (fix << 0 ) ;
4751 }
4752 }
4753 }
4754 }
4755
4756 uint32_t os::Linux::os_version() {
4757 assert(_os_version != 0, "not initialized");
4758 return _os_version & 0x00FFFFFF;
4759 }
4760
4761 bool os::Linux::os_version_is_known() {
4762 assert(_os_version != 0, "not initialized");
4763 return _os_version & 0x01000000 ? false : true;
4764 }
4765
4766 /////
4767 // glibc on Linux platform uses non-documented flag
4768 // to indicate, that some special sort of signal
4769 // trampoline is used.
4770 // We will never set this flag, and we should
4771 // ignore this flag in our diagnostic
4772 #ifdef SIGNIFICANT_SIGNAL_MASK
4773 #undef SIGNIFICANT_SIGNAL_MASK
4774 #endif
4775 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
4776
4777 static const char* get_signal_handler_name(address handler,
4778 char* buf, int buflen) {
4779 int offset = 0;
4780 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
4781 if (found) {
4782 // skip directory names
4783 const char *p1, *p2;
4784 p1 = buf;
4785 size_t len = strlen(os::file_separator());
4786 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
4787 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
4788 } else {
4789 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
4790 }
4791 return buf;
4792 }
4793
4794 static void print_signal_handler(outputStream* st, int sig,
4795 char* buf, size_t buflen) {
4796 struct sigaction sa;
4797
4798 sigaction(sig, NULL, &sa);
4799
4800 // See comment for SIGNIFICANT_SIGNAL_MASK define
4801 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4802
4803 st->print("%s: ", os::exception_name(sig, buf, buflen));
4804
4805 address handler = (sa.sa_flags & SA_SIGINFO)
4806 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
4807 : CAST_FROM_FN_PTR(address, sa.sa_handler);
4808
4809 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
4810 st->print("SIG_DFL");
4811 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
4812 st->print("SIG_IGN");
4813 } else {
4814 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
4815 }
4816
4817 st->print(", sa_mask[0]=");
4818 os::Posix::print_signal_set_short(st, &sa.sa_mask);
4819
4820 address rh = VMError::get_resetted_sighandler(sig);
4821 // May be, handler was resetted by VMError?
4822 if (rh != NULL) {
4823 handler = rh;
4824 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
4825 }
4826
4827 st->print(", sa_flags=");
4828 os::Posix::print_sa_flags(st, sa.sa_flags);
4829
4830 // Check: is it our handler?
4831 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
4832 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
4833 // It is our signal handler
4834 // check for flags, reset system-used one!
4835 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) {
4836 st->print(
4837 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
4838 os::Linux::get_our_sigflags(sig));
4839 }
4840 }
4841 st->cr();
4842 }
4843
4844
4845 #define DO_SIGNAL_CHECK(sig) \
4846 do { \
4847 if (!sigismember(&check_signal_done, sig)) { \
4848 os::Linux::check_signal_handler(sig); \
4849 } \
4850 } while (0)
4851
4852 // This method is a periodic task to check for misbehaving JNI applications
4853 // under CheckJNI, we can add any periodic checks here
4854
4855 void os::run_periodic_checks() {
4856 if (check_signals == false) return;
4857
4858 // SEGV and BUS if overridden could potentially prevent
4859 // generation of hs*.log in the event of a crash, debugging
4860 // such a case can be very challenging, so we absolutely
4861 // check the following for a good measure:
4862 DO_SIGNAL_CHECK(SIGSEGV);
4863 DO_SIGNAL_CHECK(SIGILL);
4864 DO_SIGNAL_CHECK(SIGFPE);
4865 DO_SIGNAL_CHECK(SIGBUS);
4866 DO_SIGNAL_CHECK(SIGPIPE);
4867 DO_SIGNAL_CHECK(SIGXFSZ);
4868 #if defined(PPC64)
4869 DO_SIGNAL_CHECK(SIGTRAP);
4870 #endif
4871
4872 // ReduceSignalUsage allows the user to override these handlers
4873 // see comments at the very top and jvm_md.h
4874 if (!ReduceSignalUsage) {
4875 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
4876 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
4877 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
4878 DO_SIGNAL_CHECK(BREAK_SIGNAL);
4879 }
4880
4881 DO_SIGNAL_CHECK(SR_signum);
4882 }
4883
4884 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
4885
4886 static os_sigaction_t os_sigaction = NULL;
4887
4888 void os::Linux::check_signal_handler(int sig) {
4889 char buf[O_BUFLEN];
4890 address jvmHandler = NULL;
4891
4892
4893 struct sigaction act;
4894 if (os_sigaction == NULL) {
4895 // only trust the default sigaction, in case it has been interposed
4896 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
4897 if (os_sigaction == NULL) return;
4898 }
4899
4900 os_sigaction(sig, (struct sigaction*)NULL, &act);
4901
4902
4903 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4904
4905 address thisHandler = (act.sa_flags & SA_SIGINFO)
4906 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
4907 : CAST_FROM_FN_PTR(address, act.sa_handler);
4908
4909
4910 switch (sig) {
4911 case SIGSEGV:
4912 case SIGBUS:
4913 case SIGFPE:
4914 case SIGPIPE:
4915 case SIGILL:
4916 case SIGXFSZ:
4917 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
4918 break;
4919
4920 case SHUTDOWN1_SIGNAL:
4921 case SHUTDOWN2_SIGNAL:
4922 case SHUTDOWN3_SIGNAL:
4923 case BREAK_SIGNAL:
4924 jvmHandler = (address)user_handler();
4925 break;
4926
4927 default:
4928 if (sig == SR_signum) {
4929 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
4930 } else {
4931 return;
4932 }
4933 break;
4934 }
4935
4936 if (thisHandler != jvmHandler) {
4937 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
4938 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
4939 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
4940 // No need to check this sig any longer
4941 sigaddset(&check_signal_done, sig);
4942 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
4943 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
4944 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
4945 exception_name(sig, buf, O_BUFLEN));
4946 }
4947 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) {
4948 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
4949 tty->print("expected:");
4950 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig));
4951 tty->cr();
4952 tty->print(" found:");
4953 os::Posix::print_sa_flags(tty, act.sa_flags);
4954 tty->cr();
4955 // No need to check this sig any longer
4956 sigaddset(&check_signal_done, sig);
4957 }
4958
4959 // Dump all the signal
4960 if (sigismember(&check_signal_done, sig)) {
4961 print_signal_handlers(tty, buf, O_BUFLEN);
4962 }
4963 }
4964
4965 extern void report_error(char* file_name, int line_no, char* title,
4966 char* format, ...);
4967
4968 // this is called _before_ most of the global arguments have been parsed
4969 void os::init(void) {
4970 char dummy; // used to get a guess on initial stack address
4971
4972 clock_tics_per_sec = sysconf(_SC_CLK_TCK);
4973
4974 init_random(1234567);
4975
4976 Linux::set_page_size(sysconf(_SC_PAGESIZE));
4977 if (Linux::page_size() == -1) {
4978 fatal("os_linux.cpp: os::init: sysconf failed (%s)",
4979 os::strerror(errno));
4980 }
4981 init_page_sizes((size_t) Linux::page_size());
4982
4983 Linux::initialize_system_info();
4984
4985 Linux::initialize_os_info();
4986
4987 // _main_thread points to the thread that created/loaded the JVM.
4988 Linux::_main_thread = pthread_self();
4989
4990 Linux::clock_init();
4991 initial_time_count = javaTimeNanos();
4992
4993 // retrieve entry point for pthread_setname_np
4994 Linux::_pthread_setname_np =
4995 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np");
4996
4997 os::Posix::init();
4998 }
4999
5000 // To install functions for atexit system call
5001 extern "C" {
5002 static void perfMemory_exit_helper() {
5003 perfMemory_exit();
5004 }
5005 }
5006
5007 void os::pd_init_container_support() {
5008 OSContainer::init();
5009 }
5010
5011 // this is called _after_ the global arguments have been parsed
5012 jint os::init_2(void) {
5013
5014 os::Posix::init_2();
5015
5016 Linux::fast_thread_clock_init();
5017
5018 // initialize suspend/resume support - must do this before signal_sets_init()
5019 if (SR_initialize() != 0) {
5020 perror("SR_initialize failed");
5021 return JNI_ERR;
5022 }
5023
5024 Linux::signal_sets_init();
5025 Linux::install_signal_handlers();
5026 // Initialize data for jdk.internal.misc.Signal
5027 if (!ReduceSignalUsage) {
5028 jdk_misc_signal_init();
5029 }
5030
5031 // Check and sets minimum stack sizes against command line options
5032 if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
5033 return JNI_ERR;
5034 }
5035
5036 suppress_primordial_thread_resolution = Arguments::created_by_java_launcher();
5037 if (!suppress_primordial_thread_resolution) {
5038 Linux::capture_initial_stack(JavaThread::stack_size_at_create());
5039 }
5040
5041 #if defined(IA32)
5042 workaround_expand_exec_shield_cs_limit();
5043 #endif
5044
5045 Linux::libpthread_init();
5046 Linux::sched_getcpu_init();
5047 log_info(os)("HotSpot is running with %s, %s",
5048 Linux::glibc_version(), Linux::libpthread_version());
5049
5050 if (UseNUMA) {
5051 if (!Linux::libnuma_init()) {
5052 UseNUMA = false;
5053 } else {
5054 if ((Linux::numa_max_node() < 1) || Linux::isbound_to_single_node()) {
5055 // If there's only one node (they start from 0) or if the process
5056 // is bound explicitly to a single node using membind, disable NUMA.
5057 UseNUMA = false;
5058 }
5059 }
5060
5061 if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) {
5062 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way
5063 // we can make the adaptive lgrp chunk resizing work. If the user specified both
5064 // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn
5065 // and disable adaptive resizing.
5066 if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) {
5067 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, "
5068 "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)");
5069 UseAdaptiveSizePolicy = false;
5070 UseAdaptiveNUMAChunkSizing = false;
5071 }
5072 }
5073
5074 if (!UseNUMA && ForceNUMA) {
5075 UseNUMA = true;
5076 }
5077 }
5078
5079 if (MaxFDLimit) {
5080 // set the number of file descriptors to max. print out error
5081 // if getrlimit/setrlimit fails but continue regardless.
5082 struct rlimit nbr_files;
5083 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
5084 if (status != 0) {
5085 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
5086 } else {
5087 nbr_files.rlim_cur = nbr_files.rlim_max;
5088 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
5089 if (status != 0) {
5090 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
5091 }
5092 }
5093 }
5094
5095 // Initialize lock used to serialize thread creation (see os::create_thread)
5096 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false));
5097
5098 // at-exit methods are called in the reverse order of their registration.
5099 // atexit functions are called on return from main or as a result of a
5100 // call to exit(3C). There can be only 32 of these functions registered
5101 // and atexit() does not set errno.
5102
5103 if (PerfAllowAtExitRegistration) {
5104 // only register atexit functions if PerfAllowAtExitRegistration is set.
5105 // atexit functions can be delayed until process exit time, which
5106 // can be problematic for embedded VM situations. Embedded VMs should
5107 // call DestroyJavaVM() to assure that VM resources are released.
5108
5109 // note: perfMemory_exit_helper atexit function may be removed in
5110 // the future if the appropriate cleanup code can be added to the
5111 // VM_Exit VMOperation's doit method.
5112 if (atexit(perfMemory_exit_helper) != 0) {
5113 warning("os::init_2 atexit(perfMemory_exit_helper) failed");
5114 }
5115 }
5116
5117 // initialize thread priority policy
5118 prio_init();
5119
5120 if (!FLAG_IS_DEFAULT(AllocateHeapAt)) {
5121 set_coredump_filter(false /*largepages*/, true /*dax_shared*/);
5122 }
5123 return JNI_OK;
5124 }
5125
5126 // Mark the polling page as unreadable
5127 void os::make_polling_page_unreadable(void) {
5128 if (!guard_memory((char*)_polling_page, Linux::page_size())) {
5129 fatal("Could not disable polling page");
5130 }
5131 }
5132
5133 // Mark the polling page as readable
5134 void os::make_polling_page_readable(void) {
5135 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) {
5136 fatal("Could not enable polling page");
5137 }
5138 }
5139
5140 // older glibc versions don't have this macro (which expands to
5141 // an optimized bit-counting function) so we have to roll our own
5142 #ifndef CPU_COUNT
5143
5144 static int _cpu_count(const cpu_set_t* cpus) {
5145 int count = 0;
5146 // only look up to the number of configured processors
5147 for (int i = 0; i < os::processor_count(); i++) {
5148 if (CPU_ISSET(i, cpus)) {
5149 count++;
5150 }
5151 }
5152 return count;
5153 }
5154
5155 #define CPU_COUNT(cpus) _cpu_count(cpus)
5156
5157 #endif // CPU_COUNT
5158
5159 // Get the current number of available processors for this process.
5160 // This value can change at any time during a process's lifetime.
5161 // sched_getaffinity gives an accurate answer as it accounts for cpusets.
5162 // If it appears there may be more than 1024 processors then we do a
5163 // dynamic check - see 6515172 for details.
5164 // If anything goes wrong we fallback to returning the number of online
5165 // processors - which can be greater than the number available to the process.
5166 int os::Linux::active_processor_count() {
5167 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors
5168 cpu_set_t* cpus_p = &cpus;
5169 int cpus_size = sizeof(cpu_set_t);
5170
5171 int configured_cpus = os::processor_count(); // upper bound on available cpus
5172 int cpu_count = 0;
5173
5174 // old build platforms may not support dynamic cpu sets
5175 #ifdef CPU_ALLOC
5176
5177 // To enable easy testing of the dynamic path on different platforms we
5178 // introduce a diagnostic flag: UseCpuAllocPath
5179 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) {
5180 // kernel may use a mask bigger than cpu_set_t
5181 log_trace(os)("active_processor_count: using dynamic path %s"
5182 "- configured processors: %d",
5183 UseCpuAllocPath ? "(forced) " : "",
5184 configured_cpus);
5185 cpus_p = CPU_ALLOC(configured_cpus);
5186 if (cpus_p != NULL) {
5187 cpus_size = CPU_ALLOC_SIZE(configured_cpus);
5188 // zero it just to be safe
5189 CPU_ZERO_S(cpus_size, cpus_p);
5190 }
5191 else {
5192 // failed to allocate so fallback to online cpus
5193 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
5194 log_trace(os)("active_processor_count: "
5195 "CPU_ALLOC failed (%s) - using "
5196 "online processor count: %d",
5197 os::strerror(errno), online_cpus);
5198 return online_cpus;
5199 }
5200 }
5201 else {
5202 log_trace(os)("active_processor_count: using static path - configured processors: %d",
5203 configured_cpus);
5204 }
5205 #else // CPU_ALLOC
5206 // these stubs won't be executed
5207 #define CPU_COUNT_S(size, cpus) -1
5208 #define CPU_FREE(cpus)
5209
5210 log_trace(os)("active_processor_count: only static path available - configured processors: %d",
5211 configured_cpus);
5212 #endif // CPU_ALLOC
5213
5214 // pid 0 means the current thread - which we have to assume represents the process
5215 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) {
5216 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5217 cpu_count = CPU_COUNT_S(cpus_size, cpus_p);
5218 }
5219 else {
5220 cpu_count = CPU_COUNT(cpus_p);
5221 }
5222 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count);
5223 }
5224 else {
5225 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN);
5226 warning("sched_getaffinity failed (%s)- using online processor count (%d) "
5227 "which may exceed available processors", os::strerror(errno), cpu_count);
5228 }
5229
5230 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5231 CPU_FREE(cpus_p);
5232 }
5233
5234 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check");
5235 return cpu_count;
5236 }
5237
5238 // Determine the active processor count from one of
5239 // three different sources:
5240 //
5241 // 1. User option -XX:ActiveProcessorCount
5242 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN)
5243 // 3. extracted from cgroup cpu subsystem (shares and quotas)
5244 //
5245 // Option 1, if specified, will always override.
5246 // If the cgroup subsystem is active and configured, we
5247 // will return the min of the cgroup and option 2 results.
5248 // This is required since tools, such as numactl, that
5249 // alter cpu affinity do not update cgroup subsystem
5250 // cpuset configuration files.
5251 int os::active_processor_count() {
5252 // User has overridden the number of active processors
5253 if (ActiveProcessorCount > 0) {
5254 log_trace(os)("active_processor_count: "
5255 "active processor count set by user : %d",
5256 ActiveProcessorCount);
5257 return ActiveProcessorCount;
5258 }
5259
5260 int active_cpus;
5261 if (OSContainer::is_containerized()) {
5262 active_cpus = OSContainer::active_processor_count();
5263 log_trace(os)("active_processor_count: determined by OSContainer: %d",
5264 active_cpus);
5265 } else {
5266 active_cpus = os::Linux::active_processor_count();
5267 }
5268
5269 return active_cpus;
5270 }
5271
5272 uint os::processor_id() {
5273 const int id = Linux::sched_getcpu();
5274 assert(id >= 0 && id < _processor_count, "Invalid processor id");
5275 return (uint)id;
5276 }
5277
5278 void os::set_native_thread_name(const char *name) {
5279 if (Linux::_pthread_setname_np) {
5280 char buf [16]; // according to glibc manpage, 16 chars incl. '/0'
5281 snprintf(buf, sizeof(buf), "%s", name);
5282 buf[sizeof(buf) - 1] = '\0';
5283 const int rc = Linux::_pthread_setname_np(pthread_self(), buf);
5284 // ERANGE should not happen; all other errors should just be ignored.
5285 assert(rc != ERANGE, "pthread_setname_np failed");
5286 }
5287 }
5288
5289 bool os::distribute_processes(uint length, uint* distribution) {
5290 // Not yet implemented.
5291 return false;
5292 }
5293
5294 bool os::bind_to_processor(uint processor_id) {
5295 // Not yet implemented.
5296 return false;
5297 }
5298
5299 ///
5300
5301 void os::SuspendedThreadTask::internal_do_task() {
5302 if (do_suspend(_thread->osthread())) {
5303 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
5304 do_task(context);
5305 do_resume(_thread->osthread());
5306 }
5307 }
5308
5309 ////////////////////////////////////////////////////////////////////////////////
5310 // debug support
5311
5312 bool os::find(address addr, outputStream* st) {
5313 Dl_info dlinfo;
5314 memset(&dlinfo, 0, sizeof(dlinfo));
5315 if (dladdr(addr, &dlinfo) != 0) {
5316 st->print(PTR_FORMAT ": ", p2i(addr));
5317 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
5318 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname,
5319 p2i(addr) - p2i(dlinfo.dli_saddr));
5320 } else if (dlinfo.dli_fbase != NULL) {
5321 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase));
5322 } else {
5323 st->print("<absolute address>");
5324 }
5325 if (dlinfo.dli_fname != NULL) {
5326 st->print(" in %s", dlinfo.dli_fname);
5327 }
5328 if (dlinfo.dli_fbase != NULL) {
5329 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase));
5330 }
5331 st->cr();
5332
5333 if (Verbose) {
5334 // decode some bytes around the PC
5335 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
5336 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
5337 address lowest = (address) dlinfo.dli_sname;
5338 if (!lowest) lowest = (address) dlinfo.dli_fbase;
5339 if (begin < lowest) begin = lowest;
5340 Dl_info dlinfo2;
5341 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
5342 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
5343 end = (address) dlinfo2.dli_saddr;
5344 }
5345 Disassembler::decode(begin, end, st);
5346 }
5347 return true;
5348 }
5349 return false;
5350 }
5351
5352 ////////////////////////////////////////////////////////////////////////////////
5353 // misc
5354
5355 // This does not do anything on Linux. This is basically a hook for being
5356 // able to use structured exception handling (thread-local exception filters)
5357 // on, e.g., Win32.
5358 void
5359 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
5360 JavaCallArguments* args, Thread* thread) {
5361 f(value, method, args, thread);
5362 }
5363
5364 void os::print_statistics() {
5365 }
5366
5367 bool os::message_box(const char* title, const char* message) {
5368 int i;
5369 fdStream err(defaultStream::error_fd());
5370 for (i = 0; i < 78; i++) err.print_raw("=");
5371 err.cr();
5372 err.print_raw_cr(title);
5373 for (i = 0; i < 78; i++) err.print_raw("-");
5374 err.cr();
5375 err.print_raw_cr(message);
5376 for (i = 0; i < 78; i++) err.print_raw("=");
5377 err.cr();
5378
5379 char buf[16];
5380 // Prevent process from exiting upon "read error" without consuming all CPU
5381 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
5382
5383 return buf[0] == 'y' || buf[0] == 'Y';
5384 }
5385
5386 // Is a (classpath) directory empty?
5387 bool os::dir_is_empty(const char* path) {
5388 DIR *dir = NULL;
5389 struct dirent *ptr;
5390
5391 dir = opendir(path);
5392 if (dir == NULL) return true;
5393
5394 // Scan the directory
5395 bool result = true;
5396 while (result && (ptr = readdir(dir)) != NULL) {
5397 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
5398 result = false;
5399 }
5400 }
5401 closedir(dir);
5402 return result;
5403 }
5404
5405 // This code originates from JDK's sysOpen and open64_w
5406 // from src/solaris/hpi/src/system_md.c
5407
5408 int os::open(const char *path, int oflag, int mode) {
5409 if (strlen(path) > MAX_PATH - 1) {
5410 errno = ENAMETOOLONG;
5411 return -1;
5412 }
5413
5414 // All file descriptors that are opened in the Java process and not
5415 // specifically destined for a subprocess should have the close-on-exec
5416 // flag set. If we don't set it, then careless 3rd party native code
5417 // might fork and exec without closing all appropriate file descriptors
5418 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in
5419 // turn might:
5420 //
5421 // - cause end-of-file to fail to be detected on some file
5422 // descriptors, resulting in mysterious hangs, or
5423 //
5424 // - might cause an fopen in the subprocess to fail on a system
5425 // suffering from bug 1085341.
5426 //
5427 // (Yes, the default setting of the close-on-exec flag is a Unix
5428 // design flaw)
5429 //
5430 // See:
5431 // 1085341: 32-bit stdio routines should support file descriptors >255
5432 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
5433 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
5434 //
5435 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open().
5436 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor
5437 // because it saves a system call and removes a small window where the flag
5438 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored
5439 // and we fall back to using FD_CLOEXEC (see below).
5440 #ifdef O_CLOEXEC
5441 oflag |= O_CLOEXEC;
5442 #endif
5443
5444 int fd = ::open64(path, oflag, mode);
5445 if (fd == -1) return -1;
5446
5447 //If the open succeeded, the file might still be a directory
5448 {
5449 struct stat64 buf64;
5450 int ret = ::fstat64(fd, &buf64);
5451 int st_mode = buf64.st_mode;
5452
5453 if (ret != -1) {
5454 if ((st_mode & S_IFMT) == S_IFDIR) {
5455 errno = EISDIR;
5456 ::close(fd);
5457 return -1;
5458 }
5459 } else {
5460 ::close(fd);
5461 return -1;
5462 }
5463 }
5464
5465 #ifdef FD_CLOEXEC
5466 // Validate that the use of the O_CLOEXEC flag on open above worked.
5467 // With recent kernels, we will perform this check exactly once.
5468 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
5469 if (!O_CLOEXEC_is_known_to_work) {
5470 int flags = ::fcntl(fd, F_GETFD);
5471 if (flags != -1) {
5472 if ((flags & FD_CLOEXEC) != 0)
5473 O_CLOEXEC_is_known_to_work = 1;
5474 else
5475 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
5476 }
5477 }
5478 #endif
5479
5480 return fd;
5481 }
5482
5483
5484 // create binary file, rewriting existing file if required
5485 int os::create_binary_file(const char* path, bool rewrite_existing) {
5486 int oflags = O_WRONLY | O_CREAT;
5487 if (!rewrite_existing) {
5488 oflags |= O_EXCL;
5489 }
5490 return ::open64(path, oflags, S_IREAD | S_IWRITE);
5491 }
5492
5493 // return current position of file pointer
5494 jlong os::current_file_offset(int fd) {
5495 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
5496 }
5497
5498 // move file pointer to the specified offset
5499 jlong os::seek_to_file_offset(int fd, jlong offset) {
5500 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
5501 }
5502
5503 // This code originates from JDK's sysAvailable
5504 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
5505
5506 int os::available(int fd, jlong *bytes) {
5507 jlong cur, end;
5508 int mode;
5509 struct stat64 buf64;
5510
5511 if (::fstat64(fd, &buf64) >= 0) {
5512 mode = buf64.st_mode;
5513 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
5514 int n;
5515 if (::ioctl(fd, FIONREAD, &n) >= 0) {
5516 *bytes = n;
5517 return 1;
5518 }
5519 }
5520 }
5521 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
5522 return 0;
5523 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
5524 return 0;
5525 } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
5526 return 0;
5527 }
5528 *bytes = end - cur;
5529 return 1;
5530 }
5531
5532 // Map a block of memory.
5533 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
5534 char *addr, size_t bytes, bool read_only,
5535 bool allow_exec) {
5536 int prot;
5537 int flags = MAP_PRIVATE;
5538
5539 if (read_only) {
5540 prot = PROT_READ;
5541 } else {
5542 prot = PROT_READ | PROT_WRITE;
5543 }
5544
5545 if (allow_exec) {
5546 prot |= PROT_EXEC;
5547 }
5548
5549 if (addr != NULL) {
5550 flags |= MAP_FIXED;
5551 }
5552
5553 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
5554 fd, file_offset);
5555 if (mapped_address == MAP_FAILED) {
5556 return NULL;
5557 }
5558 return mapped_address;
5559 }
5560
5561
5562 // Remap a block of memory.
5563 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
5564 char *addr, size_t bytes, bool read_only,
5565 bool allow_exec) {
5566 // same as map_memory() on this OS
5567 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
5568 allow_exec);
5569 }
5570
5571
5572 // Unmap a block of memory.
5573 bool os::pd_unmap_memory(char* addr, size_t bytes) {
5574 return munmap(addr, bytes) == 0;
5575 }
5576
5577 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time);
5578
5579 static jlong fast_cpu_time(Thread *thread) {
5580 clockid_t clockid;
5581 int rc = os::Linux::pthread_getcpuclockid(thread->osthread()->pthread_id(),
5582 &clockid);
5583 if (rc == 0) {
5584 return os::Linux::fast_thread_cpu_time(clockid);
5585 } else {
5586 // It's possible to encounter a terminated native thread that failed
5587 // to detach itself from the VM - which should result in ESRCH.
5588 assert_status(rc == ESRCH, rc, "pthread_getcpuclockid failed");
5589 return -1;
5590 }
5591 }
5592
5593 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
5594 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
5595 // of a thread.
5596 //
5597 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
5598 // the fast estimate available on the platform.
5599
5600 jlong os::current_thread_cpu_time() {
5601 if (os::Linux::supports_fast_thread_cpu_time()) {
5602 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5603 } else {
5604 // return user + sys since the cost is the same
5605 return slow_thread_cpu_time(Thread::current(), true /* user + sys */);
5606 }
5607 }
5608
5609 jlong os::thread_cpu_time(Thread* thread) {
5610 // consistent with what current_thread_cpu_time() returns
5611 if (os::Linux::supports_fast_thread_cpu_time()) {
5612 return fast_cpu_time(thread);
5613 } else {
5614 return slow_thread_cpu_time(thread, true /* user + sys */);
5615 }
5616 }
5617
5618 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
5619 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5620 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5621 } else {
5622 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time);
5623 }
5624 }
5625
5626 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5627 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5628 return fast_cpu_time(thread);
5629 } else {
5630 return slow_thread_cpu_time(thread, user_sys_cpu_time);
5631 }
5632 }
5633
5634 // -1 on error.
5635 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5636 pid_t tid = thread->osthread()->thread_id();
5637 char *s;
5638 char stat[2048];
5639 int statlen;
5640 char proc_name[64];
5641 int count;
5642 long sys_time, user_time;
5643 char cdummy;
5644 int idummy;
5645 long ldummy;
5646 FILE *fp;
5647
5648 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid);
5649 fp = fopen(proc_name, "r");
5650 if (fp == NULL) return -1;
5651 statlen = fread(stat, 1, 2047, fp);
5652 stat[statlen] = '\0';
5653 fclose(fp);
5654
5655 // Skip pid and the command string. Note that we could be dealing with
5656 // weird command names, e.g. user could decide to rename java launcher
5657 // to "java 1.4.2 :)", then the stat file would look like
5658 // 1234 (java 1.4.2 :)) R ... ...
5659 // We don't really need to know the command string, just find the last
5660 // occurrence of ")" and then start parsing from there. See bug 4726580.
5661 s = strrchr(stat, ')');
5662 if (s == NULL) return -1;
5663
5664 // Skip blank chars
5665 do { s++; } while (s && isspace(*s));
5666
5667 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu",
5668 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy,
5669 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy,
5670 &user_time, &sys_time);
5671 if (count != 13) return -1;
5672 if (user_sys_cpu_time) {
5673 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
5674 } else {
5675 return (jlong)user_time * (1000000000 / clock_tics_per_sec);
5676 }
5677 }
5678
5679 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5680 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5681 info_ptr->may_skip_backward = false; // elapsed time not wall time
5682 info_ptr->may_skip_forward = false; // elapsed time not wall time
5683 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5684 }
5685
5686 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5687 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5688 info_ptr->may_skip_backward = false; // elapsed time not wall time
5689 info_ptr->may_skip_forward = false; // elapsed time not wall time
5690 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5691 }
5692
5693 bool os::is_thread_cpu_time_supported() {
5694 return true;
5695 }
5696
5697 // System loadavg support. Returns -1 if load average cannot be obtained.
5698 // Linux doesn't yet have a (official) notion of processor sets,
5699 // so just return the system wide load average.
5700 int os::loadavg(double loadavg[], int nelem) {
5701 return ::getloadavg(loadavg, nelem);
5702 }
5703
5704 void os::pause() {
5705 char filename[MAX_PATH];
5706 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
5707 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
5708 } else {
5709 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
5710 }
5711
5712 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
5713 if (fd != -1) {
5714 struct stat buf;
5715 ::close(fd);
5716 while (::stat(filename, &buf) == 0) {
5717 (void)::poll(NULL, 0, 100);
5718 }
5719 } else {
5720 jio_fprintf(stderr,
5721 "Could not open pause file '%s', continuing immediately.\n", filename);
5722 }
5723 }
5724
5725 extern char** environ;
5726
5727 // Run the specified command in a separate process. Return its exit value,
5728 // or -1 on failure (e.g. can't fork a new process).
5729 // Unlike system(), this function can be called from signal handler. It
5730 // doesn't block SIGINT et al.
5731 int os::fork_and_exec(char* cmd) {
5732 const char * argv[4] = {"sh", "-c", cmd, NULL};
5733
5734 pid_t pid = fork();
5735
5736 if (pid < 0) {
5737 // fork failed
5738 return -1;
5739
5740 } else if (pid == 0) {
5741 // child process
5742
5743 execve("/bin/sh", (char* const*)argv, environ);
5744
5745 // execve failed
5746 _exit(-1);
5747
5748 } else {
5749 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
5750 // care about the actual exit code, for now.
5751
5752 int status;
5753
5754 // Wait for the child process to exit. This returns immediately if
5755 // the child has already exited. */
5756 while (waitpid(pid, &status, 0) < 0) {
5757 switch (errno) {
5758 case ECHILD: return 0;
5759 case EINTR: break;
5760 default: return -1;
5761 }
5762 }
5763
5764 if (WIFEXITED(status)) {
5765 // The child exited normally; get its exit code.
5766 return WEXITSTATUS(status);
5767 } else if (WIFSIGNALED(status)) {
5768 // The child exited because of a signal
5769 // The best value to return is 0x80 + signal number,
5770 // because that is what all Unix shells do, and because
5771 // it allows callers to distinguish between process exit and
5772 // process death by signal.
5773 return 0x80 + WTERMSIG(status);
5774 } else {
5775 // Unknown exit code; pass it through
5776 return status;
5777 }
5778 }
5779 }
5780
5781 // Get the default path to the core file
5782 // Returns the length of the string
5783 int os::get_core_path(char* buffer, size_t bufferSize) {
5784 /*
5785 * Max length of /proc/sys/kernel/core_pattern is 128 characters.
5786 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
5787 */
5788 const int core_pattern_len = 129;
5789 char core_pattern[core_pattern_len] = {0};
5790
5791 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY);
5792 if (core_pattern_file == -1) {
5793 return -1;
5794 }
5795
5796 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len);
5797 ::close(core_pattern_file);
5798 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') {
5799 return -1;
5800 }
5801 if (core_pattern[ret-1] == '\n') {
5802 core_pattern[ret-1] = '\0';
5803 } else {
5804 core_pattern[ret] = '\0';
5805 }
5806
5807 // Replace the %p in the core pattern with the process id. NOTE: we do this
5808 // only if the pattern doesn't start with "|", and we support only one %p in
5809 // the pattern.
5810 char *pid_pos = strstr(core_pattern, "%p");
5811 const char* tail = (pid_pos != NULL) ? (pid_pos + 2) : ""; // skip over the "%p"
5812 int written;
5813
5814 if (core_pattern[0] == '/') {
5815 if (pid_pos != NULL) {
5816 *pid_pos = '\0';
5817 written = jio_snprintf(buffer, bufferSize, "%s%d%s", core_pattern,
5818 current_process_id(), tail);
5819 } else {
5820 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern);
5821 }
5822 } else {
5823 char cwd[PATH_MAX];
5824
5825 const char* p = get_current_directory(cwd, PATH_MAX);
5826 if (p == NULL) {
5827 return -1;
5828 }
5829
5830 if (core_pattern[0] == '|') {
5831 written = jio_snprintf(buffer, bufferSize,
5832 "\"%s\" (or dumping to %s/core.%d)",
5833 &core_pattern[1], p, current_process_id());
5834 } else if (pid_pos != NULL) {
5835 *pid_pos = '\0';
5836 written = jio_snprintf(buffer, bufferSize, "%s/%s%d%s", p, core_pattern,
5837 current_process_id(), tail);
5838 } else {
5839 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern);
5840 }
5841 }
5842
5843 if (written < 0) {
5844 return -1;
5845 }
5846
5847 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) {
5848 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY);
5849
5850 if (core_uses_pid_file != -1) {
5851 char core_uses_pid = 0;
5852 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1);
5853 ::close(core_uses_pid_file);
5854
5855 if (core_uses_pid == '1') {
5856 jio_snprintf(buffer + written, bufferSize - written,
5857 ".%d", current_process_id());
5858 }
5859 }
5860 }
5861
5862 return strlen(buffer);
5863 }
5864
5865 bool os::start_debugging(char *buf, int buflen) {
5866 int len = (int)strlen(buf);
5867 char *p = &buf[len];
5868
5869 jio_snprintf(p, buflen-len,
5870 "\n\n"
5871 "Do you want to debug the problem?\n\n"
5872 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n"
5873 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
5874 "Otherwise, press RETURN to abort...",
5875 os::current_process_id(), os::current_process_id(),
5876 os::current_thread_id(), os::current_thread_id());
5877
5878 bool yes = os::message_box("Unexpected Error", buf);
5879
5880 if (yes) {
5881 // yes, user asked VM to launch debugger
5882 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d",
5883 os::current_process_id(), os::current_process_id());
5884
5885 os::fork_and_exec(buf);
5886 yes = false;
5887 }
5888 return yes;
5889 }
5890
5891
5892 // Java/Compiler thread:
5893 //
5894 // Low memory addresses
5895 // P0 +------------------------+
5896 // | |\ Java thread created by VM does not have glibc
5897 // | glibc guard page | - guard page, attached Java thread usually has
5898 // | |/ 1 glibc guard page.
5899 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
5900 // | |\
5901 // | HotSpot Guard Pages | - red, yellow and reserved pages
5902 // | |/
5903 // +------------------------+ JavaThread::stack_reserved_zone_base()
5904 // | |\
5905 // | Normal Stack | -
5906 // | |/
5907 // P2 +------------------------+ Thread::stack_base()
5908 //
5909 // Non-Java thread:
5910 //
5911 // Low memory addresses
5912 // P0 +------------------------+
5913 // | |\
5914 // | glibc guard page | - usually 1 page
5915 // | |/
5916 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
5917 // | |\
5918 // | Normal Stack | -
5919 // | |/
5920 // P2 +------------------------+ Thread::stack_base()
5921 //
5922 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size
5923 // returned from pthread_attr_getstack().
5924 // ** Due to NPTL implementation error, linux takes the glibc guard page out
5925 // of the stack size given in pthread_attr. We work around this for
5926 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.)
5927 //
5928 #ifndef ZERO
5929 static void current_stack_region(address * bottom, size_t * size) {
5930 if (os::is_primordial_thread()) {
5931 // primordial thread needs special handling because pthread_getattr_np()
5932 // may return bogus value.
5933 *bottom = os::Linux::initial_thread_stack_bottom();
5934 *size = os::Linux::initial_thread_stack_size();
5935 } else {
5936 pthread_attr_t attr;
5937
5938 int rslt = pthread_getattr_np(pthread_self(), &attr);
5939
5940 // JVM needs to know exact stack location, abort if it fails
5941 if (rslt != 0) {
5942 if (rslt == ENOMEM) {
5943 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
5944 } else {
5945 fatal("pthread_getattr_np failed with error = %d", rslt);
5946 }
5947 }
5948
5949 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
5950 fatal("Cannot locate current stack attributes!");
5951 }
5952
5953 // Work around NPTL stack guard error.
5954 size_t guard_size = 0;
5955 rslt = pthread_attr_getguardsize(&attr, &guard_size);
5956 if (rslt != 0) {
5957 fatal("pthread_attr_getguardsize failed with error = %d", rslt);
5958 }
5959 *bottom += guard_size;
5960 *size -= guard_size;
5961
5962 pthread_attr_destroy(&attr);
5963
5964 }
5965 assert(os::current_stack_pointer() >= *bottom &&
5966 os::current_stack_pointer() < *bottom + *size, "just checking");
5967 }
5968
5969 address os::current_stack_base() {
5970 address bottom;
5971 size_t size;
5972 current_stack_region(&bottom, &size);
5973 return (bottom + size);
5974 }
5975
5976 size_t os::current_stack_size() {
5977 // This stack size includes the usable stack and HotSpot guard pages
5978 // (for the threads that have Hotspot guard pages).
5979 address bottom;
5980 size_t size;
5981 current_stack_region(&bottom, &size);
5982 return size;
5983 }
5984 #endif
5985
5986 static inline struct timespec get_mtime(const char* filename) {
5987 struct stat st;
5988 int ret = os::stat(filename, &st);
5989 assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
5990 return st.st_mtim;
5991 }
5992
5993 int os::compare_file_modified_times(const char* file1, const char* file2) {
5994 struct timespec filetime1 = get_mtime(file1);
5995 struct timespec filetime2 = get_mtime(file2);
5996 int diff = filetime1.tv_sec - filetime2.tv_sec;
5997 if (diff == 0) {
5998 return filetime1.tv_nsec - filetime2.tv_nsec;
5999 }
6000 return diff;
6001 }
6002
6003 /////////////// Unit tests ///////////////
6004
6005 #ifndef PRODUCT
6006
6007 #define test_log(...) \
6008 do { \
6009 if (VerboseInternalVMTests) { \
6010 tty->print_cr(__VA_ARGS__); \
6011 tty->flush(); \
6012 } \
6013 } while (false)
6014
6015 class TestReserveMemorySpecial : AllStatic {
6016 public:
6017 static void small_page_write(void* addr, size_t size) {
6018 size_t page_size = os::vm_page_size();
6019
6020 char* end = (char*)addr + size;
6021 for (char* p = (char*)addr; p < end; p += page_size) {
6022 *p = 1;
6023 }
6024 }
6025
6026 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) {
6027 if (!UseHugeTLBFS) {
6028 return;
6029 }
6030
6031 test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size);
6032
6033 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false);
6034
6035 if (addr != NULL) {
6036 small_page_write(addr, size);
6037
6038 os::Linux::release_memory_special_huge_tlbfs(addr, size);
6039 }
6040 }
6041
6042 static void test_reserve_memory_special_huge_tlbfs_only() {
6043 if (!UseHugeTLBFS) {
6044 return;
6045 }
6046
6047 size_t lp = os::large_page_size();
6048
6049 for (size_t size = lp; size <= lp * 10; size += lp) {
6050 test_reserve_memory_special_huge_tlbfs_only(size);
6051 }
6052 }
6053
6054 static void test_reserve_memory_special_huge_tlbfs_mixed() {
6055 size_t lp = os::large_page_size();
6056 size_t ag = os::vm_allocation_granularity();
6057
6058 // sizes to test
6059 const size_t sizes[] = {
6060 lp, lp + ag, lp + lp / 2, lp * 2,
6061 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2,
6062 lp * 10, lp * 10 + lp / 2
6063 };
6064 const int num_sizes = sizeof(sizes) / sizeof(size_t);
6065
6066 // For each size/alignment combination, we test three scenarios:
6067 // 1) with req_addr == NULL
6068 // 2) with a non-null req_addr at which we expect to successfully allocate
6069 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we
6070 // expect the allocation to either fail or to ignore req_addr
6071
6072 // Pre-allocate two areas; they shall be as large as the largest allocation
6073 // and aligned to the largest alignment we will be testing.
6074 const size_t mapping_size = sizes[num_sizes - 1] * 2;
6075 char* const mapping1 = (char*) ::mmap(NULL, mapping_size,
6076 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6077 -1, 0);
6078 assert(mapping1 != MAP_FAILED, "should work");
6079
6080 char* const mapping2 = (char*) ::mmap(NULL, mapping_size,
6081 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6082 -1, 0);
6083 assert(mapping2 != MAP_FAILED, "should work");
6084
6085 // Unmap the first mapping, but leave the second mapping intact: the first
6086 // mapping will serve as a value for a "good" req_addr (case 2). The second
6087 // mapping, still intact, as "bad" req_addr (case 3).
6088 ::munmap(mapping1, mapping_size);
6089
6090 // Case 1
6091 test_log("%s, req_addr NULL:", __FUNCTION__);
6092 test_log("size align result");
6093
6094 for (int i = 0; i < num_sizes; i++) {
6095 const size_t size = sizes[i];
6096 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6097 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false);
6098 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s",
6099 size, alignment, p2i(p), (p != NULL ? "" : "(failed)"));
6100 if (p != NULL) {
6101 assert(is_aligned(p, alignment), "must be");
6102 small_page_write(p, size);
6103 os::Linux::release_memory_special_huge_tlbfs(p, size);
6104 }
6105 }
6106 }
6107
6108 // Case 2
6109 test_log("%s, req_addr non-NULL:", __FUNCTION__);
6110 test_log("size align req_addr result");
6111
6112 for (int i = 0; i < num_sizes; i++) {
6113 const size_t size = sizes[i];
6114 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6115 char* const req_addr = align_up(mapping1, alignment);
6116 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6117 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s",
6118 size, alignment, p2i(req_addr), p2i(p),
6119 ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)")));
6120 if (p != NULL) {
6121 assert(p == req_addr, "must be");
6122 small_page_write(p, size);
6123 os::Linux::release_memory_special_huge_tlbfs(p, size);
6124 }
6125 }
6126 }
6127
6128 // Case 3
6129 test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__);
6130 test_log("size align req_addr result");
6131
6132 for (int i = 0; i < num_sizes; i++) {
6133 const size_t size = sizes[i];
6134 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6135 char* const req_addr = align_up(mapping2, alignment);
6136 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6137 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s",
6138 size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)")));
6139 // as the area around req_addr contains already existing mappings, the API should always
6140 // return NULL (as per contract, it cannot return another address)
6141 assert(p == NULL, "must be");
6142 }
6143 }
6144
6145 ::munmap(mapping2, mapping_size);
6146
6147 }
6148
6149 static void test_reserve_memory_special_huge_tlbfs() {
6150 if (!UseHugeTLBFS) {
6151 return;
6152 }
6153
6154 test_reserve_memory_special_huge_tlbfs_only();
6155 test_reserve_memory_special_huge_tlbfs_mixed();
6156 }
6157
6158 static void test_reserve_memory_special_shm(size_t size, size_t alignment) {
6159 if (!UseSHM) {
6160 return;
6161 }
6162
6163 test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment);
6164
6165 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false);
6166
6167 if (addr != NULL) {
6168 assert(is_aligned(addr, alignment), "Check");
6169 assert(is_aligned(addr, os::large_page_size()), "Check");
6170
6171 small_page_write(addr, size);
6172
6173 os::Linux::release_memory_special_shm(addr, size);
6174 }
6175 }
6176
6177 static void test_reserve_memory_special_shm() {
6178 size_t lp = os::large_page_size();
6179 size_t ag = os::vm_allocation_granularity();
6180
6181 for (size_t size = ag; size < lp * 3; size += ag) {
6182 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6183 test_reserve_memory_special_shm(size, alignment);
6184 }
6185 }
6186 }
6187
6188 static void test() {
6189 test_reserve_memory_special_huge_tlbfs();
6190 test_reserve_memory_special_shm();
6191 }
6192 };
6193
6194 void TestReserveMemorySpecial_test() {
6195 TestReserveMemorySpecial::test();
6196 }
6197
6198 #endif