1 /*
2 * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 // no precompiled headers
26 #include "jvm.h"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "compiler/compileBroker.hpp"
33 #include "compiler/disassembler.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "logging/log.hpp"
36 #include "logging/logStream.hpp"
37 #include "memory/allocation.inline.hpp"
38 #include "memory/filemap.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "os_linux.inline.hpp"
41 #include "os_posix.inline.hpp"
42 #include "os_share_linux.hpp"
43 #include "osContainer_linux.hpp"
44 #include "prims/jniFastGetField.hpp"
45 #include "prims/jvm_misc.hpp"
46 #include "runtime/arguments.hpp"
47 #include "runtime/atomic.hpp"
48 #include "runtime/extendedPC.hpp"
49 #include "runtime/globals.hpp"
50 #include "runtime/interfaceSupport.inline.hpp"
51 #include "runtime/init.hpp"
52 #include "runtime/java.hpp"
53 #include "runtime/javaCalls.hpp"
54 #include "runtime/mutexLocker.hpp"
55 #include "runtime/objectMonitor.hpp"
56 #include "runtime/osThread.hpp"
57 #include "runtime/perfMemory.hpp"
58 #include "runtime/sharedRuntime.hpp"
59 #include "runtime/statSampler.hpp"
60 #include "runtime/stubRoutines.hpp"
61 #include "runtime/thread.inline.hpp"
62 #include "runtime/threadCritical.hpp"
63 #include "runtime/threadSMR.hpp"
64 #include "runtime/timer.hpp"
65 #include "runtime/vm_version.hpp"
66 #include "semaphore_posix.hpp"
67 #include "services/attachListener.hpp"
68 #include "services/memTracker.hpp"
69 #include "services/runtimeService.hpp"
70 #include "utilities/align.hpp"
71 #include "utilities/decoder.hpp"
72 #include "utilities/defaultStream.hpp"
73 #include "utilities/events.hpp"
74 #include "utilities/elfFile.hpp"
75 #include "utilities/growableArray.hpp"
76 #include "utilities/macros.hpp"
77 #include "utilities/vmError.hpp"
78
79 // put OS-includes here
80 # include <sys/types.h>
81 # include <sys/mman.h>
82 # include <sys/stat.h>
83 # include <sys/select.h>
84 # include <pthread.h>
85 # include <signal.h>
86 # include <endian.h>
87 # include <errno.h>
88 # include <dlfcn.h>
89 # include <stdio.h>
90 # include <unistd.h>
91 # include <sys/resource.h>
92 # include <pthread.h>
93 # include <sys/stat.h>
94 # include <sys/time.h>
95 # include <sys/times.h>
96 # include <sys/utsname.h>
97 # include <sys/socket.h>
98 # include <sys/wait.h>
99 # include <pwd.h>
100 # include <poll.h>
101 # include <fcntl.h>
102 # include <string.h>
103 # include <syscall.h>
104 # include <sys/sysinfo.h>
105 # include <gnu/libc-version.h>
106 # include <sys/ipc.h>
107 # include <sys/shm.h>
108 # include <link.h>
109 # include <stdint.h>
110 # include <inttypes.h>
111 # include <sys/ioctl.h>
112
113 #ifndef _GNU_SOURCE
114 #define _GNU_SOURCE
115 #include <sched.h>
116 #undef _GNU_SOURCE
117 #else
118 #include <sched.h>
119 #endif
120
121 // if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling
122 // getrusage() is prepared to handle the associated failure.
123 #ifndef RUSAGE_THREAD
124 #define RUSAGE_THREAD (1) /* only the calling thread */
125 #endif
126
127 #define MAX_PATH (2 * K)
128
129 #define MAX_SECS 100000000
130
131 // for timer info max values which include all bits
132 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
133
134 enum CoredumpFilterBit {
135 FILE_BACKED_PVT_BIT = 1 << 2,
136 FILE_BACKED_SHARED_BIT = 1 << 3,
137 LARGEPAGES_BIT = 1 << 6,
138 DAX_SHARED_BIT = 1 << 8
139 };
140
141 ////////////////////////////////////////////////////////////////////////////////
142 // global variables
143 julong os::Linux::_physical_memory = 0;
144
145 address os::Linux::_initial_thread_stack_bottom = NULL;
146 uintptr_t os::Linux::_initial_thread_stack_size = 0;
147
148 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL;
149 int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL;
150 pthread_t os::Linux::_main_thread;
151 int os::Linux::_page_size = -1;
152 bool os::Linux::_supports_fast_thread_cpu_time = false;
153 const char * os::Linux::_glibc_version = NULL;
154 const char * os::Linux::_libpthread_version = NULL;
155
156 static jlong initial_time_count=0;
157
158 static int clock_tics_per_sec = 100;
159
160 // If the VM might have been created on the primordial thread, we need to resolve the
161 // primordial thread stack bounds and check if the current thread might be the
162 // primordial thread in places. If we know that the primordial thread is never used,
163 // such as when the VM was created by one of the standard java launchers, we can
164 // avoid this
165 static bool suppress_primordial_thread_resolution = false;
166
167 // For diagnostics to print a message once. see run_periodic_checks
168 static sigset_t check_signal_done;
169 static bool check_signals = true;
170
171 // Signal number used to suspend/resume a thread
172
173 // do not use any signal number less than SIGSEGV, see 4355769
174 static int SR_signum = SIGUSR2;
175 sigset_t SR_sigset;
176
177 // utility functions
178
179 static int SR_initialize();
180
181 julong os::available_memory() {
182 return Linux::available_memory();
183 }
184
185 julong os::Linux::available_memory() {
186 // values in struct sysinfo are "unsigned long"
187 struct sysinfo si;
188 julong avail_mem;
189
190 if (OSContainer::is_containerized()) {
191 jlong mem_limit, mem_usage;
192 if ((mem_limit = OSContainer::memory_limit_in_bytes()) < 1) {
193 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
194 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
195 }
196 if (mem_limit > 0 && (mem_usage = OSContainer::memory_usage_in_bytes()) < 1) {
197 log_debug(os, container)("container memory usage failed: " JLONG_FORMAT ", using host value", mem_usage);
198 }
199 if (mem_limit > 0 && mem_usage > 0 ) {
200 avail_mem = mem_limit > mem_usage ? (julong)mem_limit - (julong)mem_usage : 0;
201 log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem);
202 return avail_mem;
203 }
204 }
205
206 sysinfo(&si);
207 avail_mem = (julong)si.freeram * si.mem_unit;
208 log_trace(os)("available memory: " JULONG_FORMAT, avail_mem);
209 return avail_mem;
210 }
211
212 julong os::physical_memory() {
213 jlong phys_mem = 0;
214 if (OSContainer::is_containerized()) {
215 jlong mem_limit;
216 if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) {
217 log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit);
218 return mem_limit;
219 }
220 log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value",
221 mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit);
222 }
223
224 phys_mem = Linux::physical_memory();
225 log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem);
226 return phys_mem;
227 }
228
229 static uint64_t initial_total_ticks = 0;
230 static uint64_t initial_steal_ticks = 0;
231 static bool has_initial_tick_info = false;
232
233 static void next_line(FILE *f) {
234 int c;
235 do {
236 c = fgetc(f);
237 } while (c != '\n' && c != EOF);
238 }
239
240 bool os::Linux::get_tick_information(CPUPerfTicks* pticks, int which_logical_cpu) {
241 FILE* fh;
242 uint64_t userTicks, niceTicks, systemTicks, idleTicks;
243 // since at least kernel 2.6 : iowait: time waiting for I/O to complete
244 // irq: time servicing interrupts; softirq: time servicing softirqs
245 uint64_t iowTicks = 0, irqTicks = 0, sirqTicks= 0;
246 // steal (since kernel 2.6.11): time spent in other OS when running in a virtualized environment
247 uint64_t stealTicks = 0;
248 // guest (since kernel 2.6.24): time spent running a virtual CPU for guest OS under the
249 // control of the Linux kernel
250 uint64_t guestNiceTicks = 0;
251 int logical_cpu = -1;
252 const int required_tickinfo_count = (which_logical_cpu == -1) ? 4 : 5;
253 int n;
254
255 memset(pticks, 0, sizeof(CPUPerfTicks));
256
257 if ((fh = fopen("/proc/stat", "r")) == NULL) {
258 return false;
259 }
260
261 if (which_logical_cpu == -1) {
262 n = fscanf(fh, "cpu " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
263 UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
264 UINT64_FORMAT " " UINT64_FORMAT " ",
265 &userTicks, &niceTicks, &systemTicks, &idleTicks,
266 &iowTicks, &irqTicks, &sirqTicks,
267 &stealTicks, &guestNiceTicks);
268 } else {
269 // Move to next line
270 next_line(fh);
271
272 // find the line for requested cpu faster to just iterate linefeeds?
273 for (int i = 0; i < which_logical_cpu; i++) {
274 next_line(fh);
275 }
276
277 n = fscanf(fh, "cpu%u " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
278 UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "
279 UINT64_FORMAT " " UINT64_FORMAT " ",
280 &logical_cpu, &userTicks, &niceTicks,
281 &systemTicks, &idleTicks, &iowTicks, &irqTicks, &sirqTicks,
282 &stealTicks, &guestNiceTicks);
283 }
284
285 fclose(fh);
286 if (n < required_tickinfo_count || logical_cpu != which_logical_cpu) {
287 return false;
288 }
289 pticks->used = userTicks + niceTicks;
290 pticks->usedKernel = systemTicks + irqTicks + sirqTicks;
291 pticks->total = userTicks + niceTicks + systemTicks + idleTicks +
292 iowTicks + irqTicks + sirqTicks + stealTicks + guestNiceTicks;
293
294 if (n > required_tickinfo_count + 3) {
295 pticks->steal = stealTicks;
296 pticks->has_steal_ticks = true;
297 } else {
298 pticks->steal = 0;
299 pticks->has_steal_ticks = false;
300 }
301
302 return true;
303 }
304
305 // Return true if user is running as root.
306
307 bool os::have_special_privileges() {
308 static bool init = false;
309 static bool privileges = false;
310 if (!init) {
311 privileges = (getuid() != geteuid()) || (getgid() != getegid());
312 init = true;
313 }
314 return privileges;
315 }
316
317
318 #ifndef SYS_gettid
319 // i386: 224, ia64: 1105, amd64: 186, sparc 143
320 #ifdef __ia64__
321 #define SYS_gettid 1105
322 #else
323 #ifdef __i386__
324 #define SYS_gettid 224
325 #else
326 #ifdef __amd64__
327 #define SYS_gettid 186
328 #else
329 #ifdef __sparc__
330 #define SYS_gettid 143
331 #else
332 #error define gettid for the arch
333 #endif
334 #endif
335 #endif
336 #endif
337 #endif
338
339
340 // pid_t gettid()
341 //
342 // Returns the kernel thread id of the currently running thread. Kernel
343 // thread id is used to access /proc.
344 pid_t os::Linux::gettid() {
345 int rslt = syscall(SYS_gettid);
346 assert(rslt != -1, "must be."); // old linuxthreads implementation?
347 return (pid_t)rslt;
348 }
349
350 // Most versions of linux have a bug where the number of processors are
351 // determined by looking at the /proc file system. In a chroot environment,
352 // the system call returns 1.
353 static bool unsafe_chroot_detected = false;
354 static const char *unstable_chroot_error = "/proc file system not found.\n"
355 "Java may be unstable running multithreaded in a chroot "
356 "environment on Linux when /proc filesystem is not mounted.";
357
358 void os::Linux::initialize_system_info() {
359 set_processor_count(sysconf(_SC_NPROCESSORS_CONF));
360 if (processor_count() == 1) {
361 pid_t pid = os::Linux::gettid();
362 char fname[32];
363 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid);
364 FILE *fp = fopen(fname, "r");
365 if (fp == NULL) {
366 unsafe_chroot_detected = true;
367 } else {
368 fclose(fp);
369 }
370 }
371 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE);
372 assert(processor_count() > 0, "linux error");
373 }
374
375 void os::init_system_properties_values() {
376 // The next steps are taken in the product version:
377 //
378 // Obtain the JAVA_HOME value from the location of libjvm.so.
379 // This library should be located at:
380 // <JAVA_HOME>/lib/{client|server}/libjvm.so.
381 //
382 // If "/jre/lib/" appears at the right place in the path, then we
383 // assume libjvm.so is installed in a JDK and we use this path.
384 //
385 // Otherwise exit with message: "Could not create the Java virtual machine."
386 //
387 // The following extra steps are taken in the debugging version:
388 //
389 // If "/jre/lib/" does NOT appear at the right place in the path
390 // instead of exit check for $JAVA_HOME environment variable.
391 //
392 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
393 // then we append a fake suffix "hotspot/libjvm.so" to this path so
394 // it looks like libjvm.so is installed there
395 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
396 //
397 // Otherwise exit.
398 //
399 // Important note: if the location of libjvm.so changes this
400 // code needs to be changed accordingly.
401
402 // See ld(1):
403 // The linker uses the following search paths to locate required
404 // shared libraries:
405 // 1: ...
406 // ...
407 // 7: The default directories, normally /lib and /usr/lib.
408 #ifndef OVERRIDE_LIBPATH
409 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390)
410 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib"
411 #else
412 #define DEFAULT_LIBPATH "/lib:/usr/lib"
413 #endif
414 #else
415 #define DEFAULT_LIBPATH OVERRIDE_LIBPATH
416 #endif
417
418 // Base path of extensions installed on the system.
419 #define SYS_EXT_DIR "/usr/java/packages"
420 #define EXTENSIONS_DIR "/lib/ext"
421
422 // Buffer that fits several sprintfs.
423 // Note that the space for the colon and the trailing null are provided
424 // by the nulls included by the sizeof operator.
425 const size_t bufsize =
426 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
427 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
428 char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
429
430 // sysclasspath, java_home, dll_dir
431 {
432 char *pslash;
433 os::jvm_path(buf, bufsize);
434
435 // Found the full path to libjvm.so.
436 // Now cut the path to <java_home>/jre if we can.
437 pslash = strrchr(buf, '/');
438 if (pslash != NULL) {
439 *pslash = '\0'; // Get rid of /libjvm.so.
440 }
441 pslash = strrchr(buf, '/');
442 if (pslash != NULL) {
443 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
444 }
445 Arguments::set_dll_dir(buf);
446
447 if (pslash != NULL) {
448 pslash = strrchr(buf, '/');
449 if (pslash != NULL) {
450 *pslash = '\0'; // Get rid of /lib.
451 }
452 }
453 Arguments::set_java_home(buf);
454 if (!set_boot_path('/', ':')) {
455 vm_exit_during_initialization("Failed setting boot class path.", NULL);
456 }
457 }
458
459 // Where to look for native libraries.
460 //
461 // Note: Due to a legacy implementation, most of the library path
462 // is set in the launcher. This was to accomodate linking restrictions
463 // on legacy Linux implementations (which are no longer supported).
464 // Eventually, all the library path setting will be done here.
465 //
466 // However, to prevent the proliferation of improperly built native
467 // libraries, the new path component /usr/java/packages is added here.
468 // Eventually, all the library path setting will be done here.
469 {
470 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
471 // should always exist (until the legacy problem cited above is
472 // addressed).
473 const char *v = ::getenv("LD_LIBRARY_PATH");
474 const char *v_colon = ":";
475 if (v == NULL) { v = ""; v_colon = ""; }
476 // That's +1 for the colon and +1 for the trailing '\0'.
477 char *ld_library_path = NEW_C_HEAP_ARRAY(char,
478 strlen(v) + 1 +
479 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1,
480 mtInternal);
481 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon);
482 Arguments::set_library_path(ld_library_path);
483 FREE_C_HEAP_ARRAY(char, ld_library_path);
484 }
485
486 // Extensions directories.
487 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
488 Arguments::set_ext_dirs(buf);
489
490 FREE_C_HEAP_ARRAY(char, buf);
491
492 #undef DEFAULT_LIBPATH
493 #undef SYS_EXT_DIR
494 #undef EXTENSIONS_DIR
495 }
496
497 ////////////////////////////////////////////////////////////////////////////////
498 // breakpoint support
499
500 void os::breakpoint() {
501 BREAKPOINT;
502 }
503
504 extern "C" void breakpoint() {
505 // use debugger to set breakpoint here
506 }
507
508 ////////////////////////////////////////////////////////////////////////////////
509 // signal support
510
511 debug_only(static bool signal_sets_initialized = false);
512 static sigset_t unblocked_sigs, vm_sigs;
513
514 void os::Linux::signal_sets_init() {
515 // Should also have an assertion stating we are still single-threaded.
516 assert(!signal_sets_initialized, "Already initialized");
517 // Fill in signals that are necessarily unblocked for all threads in
518 // the VM. Currently, we unblock the following signals:
519 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
520 // by -Xrs (=ReduceSignalUsage));
521 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
522 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
523 // the dispositions or masks wrt these signals.
524 // Programs embedding the VM that want to use the above signals for their
525 // own purposes must, at this time, use the "-Xrs" option to prevent
526 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
527 // (See bug 4345157, and other related bugs).
528 // In reality, though, unblocking these signals is really a nop, since
529 // these signals are not blocked by default.
530 sigemptyset(&unblocked_sigs);
531 sigaddset(&unblocked_sigs, SIGILL);
532 sigaddset(&unblocked_sigs, SIGSEGV);
533 sigaddset(&unblocked_sigs, SIGBUS);
534 sigaddset(&unblocked_sigs, SIGFPE);
535 #if defined(PPC64)
536 sigaddset(&unblocked_sigs, SIGTRAP);
537 #endif
538 sigaddset(&unblocked_sigs, SR_signum);
539
540 if (!ReduceSignalUsage) {
541 if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
542 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
543 }
544 if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
545 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
546 }
547 if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
548 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
549 }
550 }
551 // Fill in signals that are blocked by all but the VM thread.
552 sigemptyset(&vm_sigs);
553 if (!ReduceSignalUsage) {
554 sigaddset(&vm_sigs, BREAK_SIGNAL);
555 }
556 debug_only(signal_sets_initialized = true);
557
558 }
559
560 // These are signals that are unblocked while a thread is running Java.
561 // (For some reason, they get blocked by default.)
562 sigset_t* os::Linux::unblocked_signals() {
563 assert(signal_sets_initialized, "Not initialized");
564 return &unblocked_sigs;
565 }
566
567 // These are the signals that are blocked while a (non-VM) thread is
568 // running Java. Only the VM thread handles these signals.
569 sigset_t* os::Linux::vm_signals() {
570 assert(signal_sets_initialized, "Not initialized");
571 return &vm_sigs;
572 }
573
574 void os::Linux::hotspot_sigmask(Thread* thread) {
575
576 //Save caller's signal mask before setting VM signal mask
577 sigset_t caller_sigmask;
578 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
579
580 OSThread* osthread = thread->osthread();
581 osthread->set_caller_sigmask(caller_sigmask);
582
583 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL);
584
585 if (!ReduceSignalUsage) {
586 if (thread->is_VM_thread()) {
587 // Only the VM thread handles BREAK_SIGNAL ...
588 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
589 } else {
590 // ... all other threads block BREAK_SIGNAL
591 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
592 }
593 }
594 }
595
596 //////////////////////////////////////////////////////////////////////////////
597 // detecting pthread library
598
599 void os::Linux::libpthread_init() {
600 // Save glibc and pthread version strings.
601 #if !defined(_CS_GNU_LIBC_VERSION) || \
602 !defined(_CS_GNU_LIBPTHREAD_VERSION)
603 #error "glibc too old (< 2.3.2)"
604 #endif
605
606 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0);
607 assert(n > 0, "cannot retrieve glibc version");
608 char *str = (char *)malloc(n, mtInternal);
609 confstr(_CS_GNU_LIBC_VERSION, str, n);
610 os::Linux::set_glibc_version(str);
611
612 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
613 assert(n > 0, "cannot retrieve pthread version");
614 str = (char *)malloc(n, mtInternal);
615 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n);
616 os::Linux::set_libpthread_version(str);
617 }
618
619 /////////////////////////////////////////////////////////////////////////////
620 // thread stack expansion
621
622 // os::Linux::manually_expand_stack() takes care of expanding the thread
623 // stack. Note that this is normally not needed: pthread stacks allocate
624 // thread stack using mmap() without MAP_NORESERVE, so the stack is already
625 // committed. Therefore it is not necessary to expand the stack manually.
626 //
627 // Manually expanding the stack was historically needed on LinuxThreads
628 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays
629 // it is kept to deal with very rare corner cases:
630 //
631 // For one, user may run the VM on an own implementation of threads
632 // whose stacks are - like the old LinuxThreads - implemented using
633 // mmap(MAP_GROWSDOWN).
634 //
635 // Also, this coding may be needed if the VM is running on the primordial
636 // thread. Normally we avoid running on the primordial thread; however,
637 // user may still invoke the VM on the primordial thread.
638 //
639 // The following historical comment describes the details about running
640 // on a thread stack allocated with mmap(MAP_GROWSDOWN):
641
642
643 // Force Linux kernel to expand current thread stack. If "bottom" is close
644 // to the stack guard, caller should block all signals.
645 //
646 // MAP_GROWSDOWN:
647 // A special mmap() flag that is used to implement thread stacks. It tells
648 // kernel that the memory region should extend downwards when needed. This
649 // allows early versions of LinuxThreads to only mmap the first few pages
650 // when creating a new thread. Linux kernel will automatically expand thread
651 // stack as needed (on page faults).
652 //
653 // However, because the memory region of a MAP_GROWSDOWN stack can grow on
654 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN
655 // region, it's hard to tell if the fault is due to a legitimate stack
656 // access or because of reading/writing non-exist memory (e.g. buffer
657 // overrun). As a rule, if the fault happens below current stack pointer,
658 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the
659 // application (see Linux kernel fault.c).
660 //
661 // This Linux feature can cause SIGSEGV when VM bangs thread stack for
662 // stack overflow detection.
663 //
664 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do
665 // not use MAP_GROWSDOWN.
666 //
667 // To get around the problem and allow stack banging on Linux, we need to
668 // manually expand thread stack after receiving the SIGSEGV.
669 //
670 // There are two ways to expand thread stack to address "bottom", we used
671 // both of them in JVM before 1.5:
672 // 1. adjust stack pointer first so that it is below "bottom", and then
673 // touch "bottom"
674 // 2. mmap() the page in question
675 //
676 // Now alternate signal stack is gone, it's harder to use 2. For instance,
677 // if current sp is already near the lower end of page 101, and we need to
678 // call mmap() to map page 100, it is possible that part of the mmap() frame
679 // will be placed in page 100. When page 100 is mapped, it is zero-filled.
680 // That will destroy the mmap() frame and cause VM to crash.
681 //
682 // The following code works by adjusting sp first, then accessing the "bottom"
683 // page to force a page fault. Linux kernel will then automatically expand the
684 // stack mapping.
685 //
686 // _expand_stack_to() assumes its frame size is less than page size, which
687 // should always be true if the function is not inlined.
688
689 static void NOINLINE _expand_stack_to(address bottom) {
690 address sp;
691 size_t size;
692 volatile char *p;
693
694 // Adjust bottom to point to the largest address within the same page, it
695 // gives us a one-page buffer if alloca() allocates slightly more memory.
696 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size());
697 bottom += os::Linux::page_size() - 1;
698
699 // sp might be slightly above current stack pointer; if that's the case, we
700 // will alloca() a little more space than necessary, which is OK. Don't use
701 // os::current_stack_pointer(), as its result can be slightly below current
702 // stack pointer, causing us to not alloca enough to reach "bottom".
703 sp = (address)&sp;
704
705 if (sp > bottom) {
706 size = sp - bottom;
707 p = (volatile char *)alloca(size);
708 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?");
709 p[0] = '\0';
710 }
711 }
712
713 void os::Linux::expand_stack_to(address bottom) {
714 _expand_stack_to(bottom);
715 }
716
717 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) {
718 assert(t!=NULL, "just checking");
719 assert(t->osthread()->expanding_stack(), "expand should be set");
720 assert(t->stack_base() != NULL, "stack_base was not initialized");
721
722 if (t->is_in_usable_stack(addr)) {
723 sigset_t mask_all, old_sigset;
724 sigfillset(&mask_all);
725 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset);
726 _expand_stack_to(addr);
727 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL);
728 return true;
729 }
730 return false;
731 }
732
733 //////////////////////////////////////////////////////////////////////////////
734 // create new thread
735
736 // Thread start routine for all newly created threads
737 static void *thread_native_entry(Thread *thread) {
738
739 thread->record_stack_base_and_size();
740
741 // Try to randomize the cache line index of hot stack frames.
742 // This helps when threads of the same stack traces evict each other's
743 // cache lines. The threads can be either from the same JVM instance, or
744 // from different JVM instances. The benefit is especially true for
745 // processors with hyperthreading technology.
746 static int counter = 0;
747 int pid = os::current_process_id();
748 alloca(((pid ^ counter++) & 7) * 128);
749
750 thread->initialize_thread_current();
751
752 OSThread* osthread = thread->osthread();
753 Monitor* sync = osthread->startThread_lock();
754
755 osthread->set_thread_id(os::current_thread_id());
756
757 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
758 os::current_thread_id(), (uintx) pthread_self());
759
760 if (UseNUMA) {
761 int lgrp_id = os::numa_get_group_id();
762 if (lgrp_id != -1) {
763 thread->set_lgrp_id(lgrp_id);
764 }
765 }
766 // initialize signal mask for this thread
767 os::Linux::hotspot_sigmask(thread);
768
769 // initialize floating point control register
770 os::Linux::init_thread_fpu_state();
771
772 // handshaking with parent thread
773 {
774 MutexLocker ml(sync, Mutex::_no_safepoint_check_flag);
775
776 // notify parent thread
777 osthread->set_state(INITIALIZED);
778 sync->notify_all();
779
780 // wait until os::start_thread()
781 while (osthread->get_state() == INITIALIZED) {
782 sync->wait_without_safepoint_check();
783 }
784 }
785
786 assert(osthread->pthread_id() != 0, "pthread_id was not set as expected");
787
788 // call one more level start routine
789 thread->call_run();
790
791 // Note: at this point the thread object may already have deleted itself.
792 // Prevent dereferencing it from here on out.
793 thread = NULL;
794
795 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
796 os::current_thread_id(), (uintx) pthread_self());
797
798 return 0;
799 }
800
801 // On Linux, glibc places static TLS blocks (for __thread variables) on
802 // the thread stack. This decreases the stack size actually available
803 // to threads.
804 //
805 // For large static TLS sizes, this may cause threads to malfunction due
806 // to insufficient stack space. This is a well-known issue in glibc:
807 // http://sourceware.org/bugzilla/show_bug.cgi?id=11787.
808 //
809 // As a workaround, we call a private but assumed-stable glibc function,
810 // __pthread_get_minstack() to obtain the minstack size and derive the
811 // static TLS size from it. We then increase the user requested stack
812 // size by this TLS size.
813 //
814 // Due to compatibility concerns, this size adjustment is opt-in and
815 // controlled via AdjustStackSizeForTLS.
816 typedef size_t (*GetMinStack)(const pthread_attr_t *attr);
817
818 GetMinStack _get_minstack_func = NULL;
819
820 static void get_minstack_init() {
821 _get_minstack_func =
822 (GetMinStack)dlsym(RTLD_DEFAULT, "__pthread_get_minstack");
823 log_info(os, thread)("Lookup of __pthread_get_minstack %s",
824 _get_minstack_func == NULL ? "failed" : "succeeded");
825 }
826
827 // Returns the size of the static TLS area glibc puts on thread stacks.
828 // The value is cached on first use, which occurs when the first thread
829 // is created during VM initialization.
830 static size_t get_static_tls_area_size(const pthread_attr_t *attr) {
831 size_t tls_size = 0;
832 if (_get_minstack_func != NULL) {
833 // Obtain the pthread minstack size by calling __pthread_get_minstack.
834 size_t minstack_size = _get_minstack_func(attr);
835
836 // Remove non-TLS area size included in minstack size returned
837 // by __pthread_get_minstack() to get the static TLS size.
838 // In glibc before 2.27, minstack size includes guard_size.
839 // In glibc 2.27 and later, guard_size is automatically added
840 // to the stack size by pthread_create and is no longer included
841 // in minstack size. In both cases, the guard_size is taken into
842 // account, so there is no need to adjust the result for that.
843 //
844 // Although __pthread_get_minstack() is a private glibc function,
845 // it is expected to have a stable behavior across future glibc
846 // versions while glibc still allocates the static TLS blocks off
847 // the stack. Following is glibc 2.28 __pthread_get_minstack():
848 //
849 // size_t
850 // __pthread_get_minstack (const pthread_attr_t *attr)
851 // {
852 // return GLRO(dl_pagesize) + __static_tls_size + PTHREAD_STACK_MIN;
853 // }
854 //
855 //
856 // The following 'minstack_size > os::vm_page_size() + PTHREAD_STACK_MIN'
857 // if check is done for precaution.
858 if (minstack_size > (size_t)os::vm_page_size() + PTHREAD_STACK_MIN) {
859 tls_size = minstack_size - os::vm_page_size() - PTHREAD_STACK_MIN;
860 }
861 }
862
863 log_info(os, thread)("Stack size adjustment for TLS is " SIZE_FORMAT,
864 tls_size);
865 return tls_size;
866 }
867
868 bool os::create_thread(Thread* thread, ThreadType thr_type,
869 size_t req_stack_size) {
870 assert(thread->osthread() == NULL, "caller responsible");
871
872 // Allocate the OSThread object
873 OSThread* osthread = new OSThread(NULL, NULL);
874 if (osthread == NULL) {
875 return false;
876 }
877
878 // set the correct thread state
879 osthread->set_thread_type(thr_type);
880
881 // Initial state is ALLOCATED but not INITIALIZED
882 osthread->set_state(ALLOCATED);
883
884 thread->set_osthread(osthread);
885
886 // init thread attributes
887 pthread_attr_t attr;
888 pthread_attr_init(&attr);
889 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
890
891 // Calculate stack size if it's not specified by caller.
892 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
893 // In glibc versions prior to 2.7 the guard size mechanism
894 // is not implemented properly. The posix standard requires adding
895 // the size of the guard pages to the stack size, instead Linux
896 // takes the space out of 'stacksize'. Thus we adapt the requested
897 // stack_size by the size of the guard pages to mimick proper
898 // behaviour. However, be careful not to end up with a size
899 // of zero due to overflow. Don't add the guard page in that case.
900 size_t guard_size = os::Linux::default_guard_size(thr_type);
901 // Configure glibc guard page. Must happen before calling
902 // get_static_tls_area_size(), which uses the guard_size.
903 pthread_attr_setguardsize(&attr, guard_size);
904
905 size_t stack_adjust_size = 0;
906 if (AdjustStackSizeForTLS) {
907 // Adjust the stack_size for on-stack TLS - see get_static_tls_area_size().
908 stack_adjust_size += get_static_tls_area_size(&attr);
909 } else {
910 stack_adjust_size += guard_size;
911 }
912
913 stack_adjust_size = align_up(stack_adjust_size, os::vm_page_size());
914 if (stack_size <= SIZE_MAX - stack_adjust_size) {
915 stack_size += stack_adjust_size;
916 }
917 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned");
918
919 int status = pthread_attr_setstacksize(&attr, stack_size);
920 assert_status(status == 0, status, "pthread_attr_setstacksize");
921
922 ThreadState state;
923
924 {
925 pthread_t tid;
926 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
927
928 char buf[64];
929 if (ret == 0) {
930 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
931 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
932 } else {
933 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
934 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
935 // Log some OS information which might explain why creating the thread failed.
936 log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
937 LogStream st(Log(os, thread)::info());
938 os::Posix::print_rlimit_info(&st);
939 os::print_memory_info(&st);
940 os::Linux::print_proc_sys_info(&st);
941 os::Linux::print_container_info(&st);
942 }
943
944 pthread_attr_destroy(&attr);
945
946 if (ret != 0) {
947 // Need to clean up stuff we've allocated so far
948 thread->set_osthread(NULL);
949 delete osthread;
950 return false;
951 }
952
953 // Store pthread info into the OSThread
954 osthread->set_pthread_id(tid);
955
956 // Wait until child thread is either initialized or aborted
957 {
958 Monitor* sync_with_child = osthread->startThread_lock();
959 MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
960 while ((state = osthread->get_state()) == ALLOCATED) {
961 sync_with_child->wait_without_safepoint_check();
962 }
963 }
964 }
965
966 // Aborted due to thread limit being reached
967 if (state == ZOMBIE) {
968 thread->set_osthread(NULL);
969 delete osthread;
970 return false;
971 }
972
973 // The thread is returned suspended (in state INITIALIZED),
974 // and is started higher up in the call chain
975 assert(state == INITIALIZED, "race condition");
976 return true;
977 }
978
979 /////////////////////////////////////////////////////////////////////////////
980 // attach existing thread
981
982 // bootstrap the main thread
983 bool os::create_main_thread(JavaThread* thread) {
984 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread");
985 return create_attached_thread(thread);
986 }
987
988 bool os::create_attached_thread(JavaThread* thread) {
989 #ifdef ASSERT
990 thread->verify_not_published();
991 #endif
992
993 // Allocate the OSThread object
994 OSThread* osthread = new OSThread(NULL, NULL);
995
996 if (osthread == NULL) {
997 return false;
998 }
999
1000 // Store pthread info into the OSThread
1001 osthread->set_thread_id(os::Linux::gettid());
1002 osthread->set_pthread_id(::pthread_self());
1003
1004 // initialize floating point control register
1005 os::Linux::init_thread_fpu_state();
1006
1007 // Initial thread state is RUNNABLE
1008 osthread->set_state(RUNNABLE);
1009
1010 thread->set_osthread(osthread);
1011
1012 if (UseNUMA) {
1013 int lgrp_id = os::numa_get_group_id();
1014 if (lgrp_id != -1) {
1015 thread->set_lgrp_id(lgrp_id);
1016 }
1017 }
1018
1019 if (os::is_primordial_thread()) {
1020 // If current thread is primordial thread, its stack is mapped on demand,
1021 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map
1022 // the entire stack region to avoid SEGV in stack banging.
1023 // It is also useful to get around the heap-stack-gap problem on SuSE
1024 // kernel (see 4821821 for details). We first expand stack to the top
1025 // of yellow zone, then enable stack yellow zone (order is significant,
1026 // enabling yellow zone first will crash JVM on SuSE Linux), so there
1027 // is no gap between the last two virtual memory regions.
1028
1029 JavaThread *jt = (JavaThread *)thread;
1030 address addr = jt->stack_reserved_zone_base();
1031 assert(addr != NULL, "initialization problem?");
1032 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled");
1033
1034 osthread->set_expanding_stack();
1035 os::Linux::manually_expand_stack(jt, addr);
1036 osthread->clear_expanding_stack();
1037 }
1038
1039 // initialize signal mask for this thread
1040 // and save the caller's signal mask
1041 os::Linux::hotspot_sigmask(thread);
1042
1043 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
1044 os::current_thread_id(), (uintx) pthread_self());
1045
1046 return true;
1047 }
1048
1049 void os::pd_start_thread(Thread* thread) {
1050 OSThread * osthread = thread->osthread();
1051 assert(osthread->get_state() != INITIALIZED, "just checking");
1052 Monitor* sync_with_child = osthread->startThread_lock();
1053 MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
1054 sync_with_child->notify();
1055 }
1056
1057 // Free Linux resources related to the OSThread
1058 void os::free_thread(OSThread* osthread) {
1059 assert(osthread != NULL, "osthread not set");
1060
1061 // We are told to free resources of the argument thread,
1062 // but we can only really operate on the current thread.
1063 assert(Thread::current()->osthread() == osthread,
1064 "os::free_thread but not current thread");
1065
1066 #ifdef ASSERT
1067 sigset_t current;
1068 sigemptyset(¤t);
1069 pthread_sigmask(SIG_SETMASK, NULL, ¤t);
1070 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!");
1071 #endif
1072
1073 // Restore caller's signal mask
1074 sigset_t sigmask = osthread->caller_sigmask();
1075 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
1076
1077 delete osthread;
1078 }
1079
1080 //////////////////////////////////////////////////////////////////////////////
1081 // primordial thread
1082
1083 // Check if current thread is the primordial thread, similar to Solaris thr_main.
1084 bool os::is_primordial_thread(void) {
1085 if (suppress_primordial_thread_resolution) {
1086 return false;
1087 }
1088 char dummy;
1089 // If called before init complete, thread stack bottom will be null.
1090 // Can be called if fatal error occurs before initialization.
1091 if (os::Linux::initial_thread_stack_bottom() == NULL) return false;
1092 assert(os::Linux::initial_thread_stack_bottom() != NULL &&
1093 os::Linux::initial_thread_stack_size() != 0,
1094 "os::init did not locate primordial thread's stack region");
1095 if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() &&
1096 (address)&dummy < os::Linux::initial_thread_stack_bottom() +
1097 os::Linux::initial_thread_stack_size()) {
1098 return true;
1099 } else {
1100 return false;
1101 }
1102 }
1103
1104 // Find the virtual memory area that contains addr
1105 static bool find_vma(address addr, address* vma_low, address* vma_high) {
1106 FILE *fp = fopen("/proc/self/maps", "r");
1107 if (fp) {
1108 address low, high;
1109 while (!feof(fp)) {
1110 if (fscanf(fp, "%p-%p", &low, &high) == 2) {
1111 if (low <= addr && addr < high) {
1112 if (vma_low) *vma_low = low;
1113 if (vma_high) *vma_high = high;
1114 fclose(fp);
1115 return true;
1116 }
1117 }
1118 for (;;) {
1119 int ch = fgetc(fp);
1120 if (ch == EOF || ch == (int)'\n') break;
1121 }
1122 }
1123 fclose(fp);
1124 }
1125 return false;
1126 }
1127
1128 // Locate primordial thread stack. This special handling of primordial thread stack
1129 // is needed because pthread_getattr_np() on most (all?) Linux distros returns
1130 // bogus value for the primordial process thread. While the launcher has created
1131 // the VM in a new thread since JDK 6, we still have to allow for the use of the
1132 // JNI invocation API from a primordial thread.
1133 void os::Linux::capture_initial_stack(size_t max_size) {
1134
1135 // max_size is either 0 (which means accept OS default for thread stacks) or
1136 // a user-specified value known to be at least the minimum needed. If we
1137 // are actually on the primordial thread we can make it appear that we have a
1138 // smaller max_size stack by inserting the guard pages at that location. But we
1139 // cannot do anything to emulate a larger stack than what has been provided by
1140 // the OS or threading library. In fact if we try to use a stack greater than
1141 // what is set by rlimit then we will crash the hosting process.
1142
1143 // Maximum stack size is the easy part, get it from RLIMIT_STACK.
1144 // If this is "unlimited" then it will be a huge value.
1145 struct rlimit rlim;
1146 getrlimit(RLIMIT_STACK, &rlim);
1147 size_t stack_size = rlim.rlim_cur;
1148
1149 // 6308388: a bug in ld.so will relocate its own .data section to the
1150 // lower end of primordial stack; reduce ulimit -s value a little bit
1151 // so we won't install guard page on ld.so's data section.
1152 // But ensure we don't underflow the stack size - allow 1 page spare
1153 if (stack_size >= (size_t)(3 * page_size())) {
1154 stack_size -= 2 * page_size();
1155 }
1156
1157 // Try to figure out where the stack base (top) is. This is harder.
1158 //
1159 // When an application is started, glibc saves the initial stack pointer in
1160 // a global variable "__libc_stack_end", which is then used by system
1161 // libraries. __libc_stack_end should be pretty close to stack top. The
1162 // variable is available since the very early days. However, because it is
1163 // a private interface, it could disappear in the future.
1164 //
1165 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar
1166 // to __libc_stack_end, it is very close to stack top, but isn't the real
1167 // stack top. Note that /proc may not exist if VM is running as a chroot
1168 // program, so reading /proc/<pid>/stat could fail. Also the contents of
1169 // /proc/<pid>/stat could change in the future (though unlikely).
1170 //
1171 // We try __libc_stack_end first. If that doesn't work, look for
1172 // /proc/<pid>/stat. If neither of them works, we use current stack pointer
1173 // as a hint, which should work well in most cases.
1174
1175 uintptr_t stack_start;
1176
1177 // try __libc_stack_end first
1178 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end");
1179 if (p && *p) {
1180 stack_start = *p;
1181 } else {
1182 // see if we can get the start_stack field from /proc/self/stat
1183 FILE *fp;
1184 int pid;
1185 char state;
1186 int ppid;
1187 int pgrp;
1188 int session;
1189 int nr;
1190 int tpgrp;
1191 unsigned long flags;
1192 unsigned long minflt;
1193 unsigned long cminflt;
1194 unsigned long majflt;
1195 unsigned long cmajflt;
1196 unsigned long utime;
1197 unsigned long stime;
1198 long cutime;
1199 long cstime;
1200 long prio;
1201 long nice;
1202 long junk;
1203 long it_real;
1204 uintptr_t start;
1205 uintptr_t vsize;
1206 intptr_t rss;
1207 uintptr_t rsslim;
1208 uintptr_t scodes;
1209 uintptr_t ecode;
1210 int i;
1211
1212 // Figure what the primordial thread stack base is. Code is inspired
1213 // by email from Hans Boehm. /proc/self/stat begins with current pid,
1214 // followed by command name surrounded by parentheses, state, etc.
1215 char stat[2048];
1216 int statlen;
1217
1218 fp = fopen("/proc/self/stat", "r");
1219 if (fp) {
1220 statlen = fread(stat, 1, 2047, fp);
1221 stat[statlen] = '\0';
1222 fclose(fp);
1223
1224 // Skip pid and the command string. Note that we could be dealing with
1225 // weird command names, e.g. user could decide to rename java launcher
1226 // to "java 1.4.2 :)", then the stat file would look like
1227 // 1234 (java 1.4.2 :)) R ... ...
1228 // We don't really need to know the command string, just find the last
1229 // occurrence of ")" and then start parsing from there. See bug 4726580.
1230 char * s = strrchr(stat, ')');
1231
1232 i = 0;
1233 if (s) {
1234 // Skip blank chars
1235 do { s++; } while (s && isspace(*s));
1236
1237 #define _UFM UINTX_FORMAT
1238 #define _DFM INTX_FORMAT
1239
1240 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2
1241 // 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
1242 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,
1243 &state, // 3 %c
1244 &ppid, // 4 %d
1245 &pgrp, // 5 %d
1246 &session, // 6 %d
1247 &nr, // 7 %d
1248 &tpgrp, // 8 %d
1249 &flags, // 9 %lu
1250 &minflt, // 10 %lu
1251 &cminflt, // 11 %lu
1252 &majflt, // 12 %lu
1253 &cmajflt, // 13 %lu
1254 &utime, // 14 %lu
1255 &stime, // 15 %lu
1256 &cutime, // 16 %ld
1257 &cstime, // 17 %ld
1258 &prio, // 18 %ld
1259 &nice, // 19 %ld
1260 &junk, // 20 %ld
1261 &it_real, // 21 %ld
1262 &start, // 22 UINTX_FORMAT
1263 &vsize, // 23 UINTX_FORMAT
1264 &rss, // 24 INTX_FORMAT
1265 &rsslim, // 25 UINTX_FORMAT
1266 &scodes, // 26 UINTX_FORMAT
1267 &ecode, // 27 UINTX_FORMAT
1268 &stack_start); // 28 UINTX_FORMAT
1269 }
1270
1271 #undef _UFM
1272 #undef _DFM
1273
1274 if (i != 28 - 2) {
1275 assert(false, "Bad conversion from /proc/self/stat");
1276 // product mode - assume we are the primordial thread, good luck in the
1277 // embedded case.
1278 warning("Can't detect primordial thread stack location - bad conversion");
1279 stack_start = (uintptr_t) &rlim;
1280 }
1281 } else {
1282 // For some reason we can't open /proc/self/stat (for example, running on
1283 // FreeBSD with a Linux emulator, or inside chroot), this should work for
1284 // most cases, so don't abort:
1285 warning("Can't detect primordial thread stack location - no /proc/self/stat");
1286 stack_start = (uintptr_t) &rlim;
1287 }
1288 }
1289
1290 // Now we have a pointer (stack_start) very close to the stack top, the
1291 // next thing to do is to figure out the exact location of stack top. We
1292 // can find out the virtual memory area that contains stack_start by
1293 // reading /proc/self/maps, it should be the last vma in /proc/self/maps,
1294 // and its upper limit is the real stack top. (again, this would fail if
1295 // running inside chroot, because /proc may not exist.)
1296
1297 uintptr_t stack_top;
1298 address low, high;
1299 if (find_vma((address)stack_start, &low, &high)) {
1300 // success, "high" is the true stack top. (ignore "low", because initial
1301 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.)
1302 stack_top = (uintptr_t)high;
1303 } else {
1304 // failed, likely because /proc/self/maps does not exist
1305 warning("Can't detect primordial thread stack location - find_vma failed");
1306 // best effort: stack_start is normally within a few pages below the real
1307 // stack top, use it as stack top, and reduce stack size so we won't put
1308 // guard page outside stack.
1309 stack_top = stack_start;
1310 stack_size -= 16 * page_size();
1311 }
1312
1313 // stack_top could be partially down the page so align it
1314 stack_top = align_up(stack_top, page_size());
1315
1316 // Allowed stack value is minimum of max_size and what we derived from rlimit
1317 if (max_size > 0) {
1318 _initial_thread_stack_size = MIN2(max_size, stack_size);
1319 } else {
1320 // Accept the rlimit max, but if stack is unlimited then it will be huge, so
1321 // clamp it at 8MB as we do on Solaris
1322 _initial_thread_stack_size = MIN2(stack_size, 8*M);
1323 }
1324 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size());
1325 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size;
1326
1327 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!");
1328
1329 if (log_is_enabled(Info, os, thread)) {
1330 // See if we seem to be on primordial process thread
1331 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) &&
1332 uintptr_t(&rlim) < stack_top;
1333
1334 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: "
1335 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT,
1336 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K,
1337 stack_top, intptr_t(_initial_thread_stack_bottom));
1338 }
1339 }
1340
1341 ////////////////////////////////////////////////////////////////////////////////
1342 // time support
1343
1344 #ifndef SUPPORTS_CLOCK_MONOTONIC
1345 #error "Build platform doesn't support clock_gettime and related functionality"
1346 #endif
1347
1348 // Time since start-up in seconds to a fine granularity.
1349 // Used by VMSelfDestructTimer and the MemProfiler.
1350 double os::elapsedTime() {
1351
1352 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
1353 }
1354
1355 jlong os::elapsed_counter() {
1356 return javaTimeNanos() - initial_time_count;
1357 }
1358
1359 jlong os::elapsed_frequency() {
1360 return NANOSECS_PER_SEC; // nanosecond resolution
1361 }
1362
1363 bool os::supports_vtime() { return true; }
1364
1365 double os::elapsedVTime() {
1366 struct rusage usage;
1367 int retval = getrusage(RUSAGE_THREAD, &usage);
1368 if (retval == 0) {
1369 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);
1370 } else {
1371 // better than nothing, but not much
1372 return elapsedTime();
1373 }
1374 }
1375
1376 jlong os::javaTimeMillis() {
1377 timeval time;
1378 int status = gettimeofday(&time, NULL);
1379 assert(status != -1, "linux error");
1380 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
1381 }
1382
1383 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
1384 timeval time;
1385 int status = gettimeofday(&time, NULL);
1386 assert(status != -1, "linux error");
1387 seconds = jlong(time.tv_sec);
1388 nanos = jlong(time.tv_usec) * 1000;
1389 }
1390
1391 void os::Linux::fast_thread_clock_init() {
1392 if (!UseLinuxPosixThreadCPUClocks) {
1393 return;
1394 }
1395 clockid_t clockid;
1396 struct timespec tp;
1397 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) =
1398 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid");
1399
1400 // Switch to using fast clocks for thread cpu time if
1401 // the clock_getres() returns 0 error code.
1402 // Note, that some kernels may support the current thread
1403 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks
1404 // returned by the pthread_getcpuclockid().
1405 // If the fast Posix clocks are supported then the clock_getres()
1406 // must return at least tp.tv_sec == 0 which means a resolution
1407 // better than 1 sec. This is extra check for reliability.
1408
1409 if (pthread_getcpuclockid_func &&
1410 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 &&
1411 os::Posix::clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) {
1412 _supports_fast_thread_cpu_time = true;
1413 _pthread_getcpuclockid = pthread_getcpuclockid_func;
1414 }
1415 }
1416
1417 jlong os::javaTimeNanos() {
1418 if (os::supports_monotonic_clock()) {
1419 struct timespec tp;
1420 int status = os::Posix::clock_gettime(CLOCK_MONOTONIC, &tp);
1421 assert(status == 0, "gettime error");
1422 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1423 return result;
1424 } else {
1425 timeval time;
1426 int status = gettimeofday(&time, NULL);
1427 assert(status != -1, "linux error");
1428 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1429 return 1000 * usecs;
1430 }
1431 }
1432
1433 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1434 if (os::supports_monotonic_clock()) {
1435 info_ptr->max_value = ALL_64_BITS;
1436
1437 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1438 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1439 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1440 } else {
1441 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1442 info_ptr->max_value = ALL_64_BITS;
1443
1444 // gettimeofday is a real time clock so it skips
1445 info_ptr->may_skip_backward = true;
1446 info_ptr->may_skip_forward = true;
1447 }
1448
1449 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1450 }
1451
1452 // Return the real, user, and system times in seconds from an
1453 // arbitrary fixed point in the past.
1454 bool os::getTimesSecs(double* process_real_time,
1455 double* process_user_time,
1456 double* process_system_time) {
1457 struct tms ticks;
1458 clock_t real_ticks = times(&ticks);
1459
1460 if (real_ticks == (clock_t) (-1)) {
1461 return false;
1462 } else {
1463 double ticks_per_second = (double) clock_tics_per_sec;
1464 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1465 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1466 *process_real_time = ((double) real_ticks) / ticks_per_second;
1467
1468 return true;
1469 }
1470 }
1471
1472
1473 char * os::local_time_string(char *buf, size_t buflen) {
1474 struct tm t;
1475 time_t long_time;
1476 time(&long_time);
1477 localtime_r(&long_time, &t);
1478 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1479 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1480 t.tm_hour, t.tm_min, t.tm_sec);
1481 return buf;
1482 }
1483
1484 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1485 return localtime_r(clock, res);
1486 }
1487
1488 ////////////////////////////////////////////////////////////////////////////////
1489 // runtime exit support
1490
1491 // Note: os::shutdown() might be called very early during initialization, or
1492 // called from signal handler. Before adding something to os::shutdown(), make
1493 // sure it is async-safe and can handle partially initialized VM.
1494 void os::shutdown() {
1495
1496 // allow PerfMemory to attempt cleanup of any persistent resources
1497 perfMemory_exit();
1498
1499 // needs to remove object in file system
1500 AttachListener::abort();
1501
1502 // flush buffered output, finish log files
1503 ostream_abort();
1504
1505 // Check for abort hook
1506 abort_hook_t abort_hook = Arguments::abort_hook();
1507 if (abort_hook != NULL) {
1508 abort_hook();
1509 }
1510
1511 }
1512
1513 // Note: os::abort() might be called very early during initialization, or
1514 // called from signal handler. Before adding something to os::abort(), make
1515 // sure it is async-safe and can handle partially initialized VM.
1516 void os::abort(bool dump_core, void* siginfo, const void* context) {
1517 os::shutdown();
1518 if (dump_core) {
1519 if (DumpPrivateMappingsInCore) {
1520 ClassLoader::close_jrt_image();
1521 }
1522 #ifndef PRODUCT
1523 fdStream out(defaultStream::output_fd());
1524 out.print_raw("Current thread is ");
1525 char buf[16];
1526 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1527 out.print_raw_cr(buf);
1528 out.print_raw_cr("Dumping core ...");
1529 #endif
1530 ::abort(); // dump core
1531 }
1532
1533 ::exit(1);
1534 }
1535
1536 // Die immediately, no exit hook, no abort hook, no cleanup.
1537 // Dump a core file, if possible, for debugging.
1538 void os::die() {
1539 if (TestUnresponsiveErrorHandler && !CreateCoredumpOnCrash) {
1540 // For TimeoutInErrorHandlingTest.java, we just kill the VM
1541 // and don't take the time to generate a core file.
1542 os::signal_raise(SIGKILL);
1543 } else {
1544 ::abort();
1545 }
1546 }
1547
1548 // thread_id is kernel thread id (similar to Solaris LWP id)
1549 intx os::current_thread_id() { return os::Linux::gettid(); }
1550 int os::current_process_id() {
1551 return ::getpid();
1552 }
1553
1554 // DLL functions
1555
1556 const char* os::dll_file_extension() { return ".so"; }
1557
1558 // This must be hard coded because it's the system's temporary
1559 // directory not the java application's temp directory, ala java.io.tmpdir.
1560 const char* os::get_temp_directory() { return "/tmp"; }
1561
1562 static bool file_exists(const char* filename) {
1563 struct stat statbuf;
1564 if (filename == NULL || strlen(filename) == 0) {
1565 return false;
1566 }
1567 return os::stat(filename, &statbuf) == 0;
1568 }
1569
1570 // check if addr is inside libjvm.so
1571 bool os::address_is_in_vm(address addr) {
1572 static address libjvm_base_addr;
1573 Dl_info dlinfo;
1574
1575 if (libjvm_base_addr == NULL) {
1576 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1577 libjvm_base_addr = (address)dlinfo.dli_fbase;
1578 }
1579 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1580 }
1581
1582 if (dladdr((void *)addr, &dlinfo) != 0) {
1583 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1584 }
1585
1586 return false;
1587 }
1588
1589 bool os::dll_address_to_function_name(address addr, char *buf,
1590 int buflen, int *offset,
1591 bool demangle) {
1592 // buf is not optional, but offset is optional
1593 assert(buf != NULL, "sanity check");
1594
1595 Dl_info dlinfo;
1596
1597 if (dladdr((void*)addr, &dlinfo) != 0) {
1598 // see if we have a matching symbol
1599 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1600 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1601 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1602 }
1603 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1604 return true;
1605 }
1606 // no matching symbol so try for just file info
1607 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1608 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1609 buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1610 return true;
1611 }
1612 }
1613 }
1614
1615 buf[0] = '\0';
1616 if (offset != NULL) *offset = -1;
1617 return false;
1618 }
1619
1620 struct _address_to_library_name {
1621 address addr; // input : memory address
1622 size_t buflen; // size of fname
1623 char* fname; // output: library name
1624 address base; // library base addr
1625 };
1626
1627 static int address_to_library_name_callback(struct dl_phdr_info *info,
1628 size_t size, void *data) {
1629 int i;
1630 bool found = false;
1631 address libbase = NULL;
1632 struct _address_to_library_name * d = (struct _address_to_library_name *)data;
1633
1634 // iterate through all loadable segments
1635 for (i = 0; i < info->dlpi_phnum; i++) {
1636 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
1637 if (info->dlpi_phdr[i].p_type == PT_LOAD) {
1638 // base address of a library is the lowest address of its loaded
1639 // segments.
1640 if (libbase == NULL || libbase > segbase) {
1641 libbase = segbase;
1642 }
1643 // see if 'addr' is within current segment
1644 if (segbase <= d->addr &&
1645 d->addr < segbase + info->dlpi_phdr[i].p_memsz) {
1646 found = true;
1647 }
1648 }
1649 }
1650
1651 // dlpi_name is NULL or empty if the ELF file is executable, return 0
1652 // so dll_address_to_library_name() can fall through to use dladdr() which
1653 // can figure out executable name from argv[0].
1654 if (found && info->dlpi_name && info->dlpi_name[0]) {
1655 d->base = libbase;
1656 if (d->fname) {
1657 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name);
1658 }
1659 return 1;
1660 }
1661 return 0;
1662 }
1663
1664 bool os::dll_address_to_library_name(address addr, char* buf,
1665 int buflen, int* offset) {
1666 // buf is not optional, but offset is optional
1667 assert(buf != NULL, "sanity check");
1668
1669 Dl_info dlinfo;
1670 struct _address_to_library_name data;
1671
1672 // There is a bug in old glibc dladdr() implementation that it could resolve
1673 // to wrong library name if the .so file has a base address != NULL. Here
1674 // we iterate through the program headers of all loaded libraries to find
1675 // out which library 'addr' really belongs to. This workaround can be
1676 // removed once the minimum requirement for glibc is moved to 2.3.x.
1677 data.addr = addr;
1678 data.fname = buf;
1679 data.buflen = buflen;
1680 data.base = NULL;
1681 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data);
1682
1683 if (rslt) {
1684 // buf already contains library name
1685 if (offset) *offset = addr - data.base;
1686 return true;
1687 }
1688 if (dladdr((void*)addr, &dlinfo) != 0) {
1689 if (dlinfo.dli_fname != NULL) {
1690 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1691 }
1692 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1693 *offset = addr - (address)dlinfo.dli_fbase;
1694 }
1695 return true;
1696 }
1697
1698 buf[0] = '\0';
1699 if (offset) *offset = -1;
1700 return false;
1701 }
1702
1703 // Loads .dll/.so and
1704 // in case of error it checks if .dll/.so was built for the
1705 // same architecture as Hotspot is running on
1706
1707
1708 // Remember the stack's state. The Linux dynamic linker will change
1709 // the stack to 'executable' at most once, so we must safepoint only once.
1710 bool os::Linux::_stack_is_executable = false;
1711
1712 // VM operation that loads a library. This is necessary if stack protection
1713 // of the Java stacks can be lost during loading the library. If we
1714 // do not stop the Java threads, they can stack overflow before the stacks
1715 // are protected again.
1716 class VM_LinuxDllLoad: public VM_Operation {
1717 private:
1718 const char *_filename;
1719 char *_ebuf;
1720 int _ebuflen;
1721 void *_lib;
1722 public:
1723 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) :
1724 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {}
1725 VMOp_Type type() const { return VMOp_LinuxDllLoad; }
1726 void doit() {
1727 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen);
1728 os::Linux::_stack_is_executable = true;
1729 }
1730 void* loaded_library() { return _lib; }
1731 };
1732
1733 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1734 void * result = NULL;
1735 bool load_attempted = false;
1736
1737 log_info(os)("attempting shared library load of %s", filename);
1738
1739 // Check whether the library to load might change execution rights
1740 // of the stack. If they are changed, the protection of the stack
1741 // guard pages will be lost. We need a safepoint to fix this.
1742 //
1743 // See Linux man page execstack(8) for more info.
1744 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) {
1745 if (!ElfFile::specifies_noexecstack(filename)) {
1746 if (!is_init_completed()) {
1747 os::Linux::_stack_is_executable = true;
1748 // This is OK - No Java threads have been created yet, and hence no
1749 // stack guard pages to fix.
1750 //
1751 // Dynamic loader will make all stacks executable after
1752 // this function returns, and will not do that again.
1753 assert(Threads::number_of_threads() == 0, "no Java threads should exist yet.");
1754 } else {
1755 warning("You have loaded library %s which might have disabled stack guard. "
1756 "The VM will try to fix the stack guard now.\n"
1757 "It's highly recommended that you fix the library with "
1758 "'execstack -c <libfile>', or link it with '-z noexecstack'.",
1759 filename);
1760
1761 assert(Thread::current()->is_Java_thread(), "must be Java thread");
1762 JavaThread *jt = JavaThread::current();
1763 if (jt->thread_state() != _thread_in_native) {
1764 // This happens when a compiler thread tries to load a hsdis-<arch>.so file
1765 // that requires ExecStack. Cannot enter safe point. Let's give up.
1766 warning("Unable to fix stack guard. Giving up.");
1767 } else {
1768 if (!LoadExecStackDllInVMThread) {
1769 // This is for the case where the DLL has an static
1770 // constructor function that executes JNI code. We cannot
1771 // load such DLLs in the VMThread.
1772 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1773 }
1774
1775 ThreadInVMfromNative tiv(jt);
1776 debug_only(VMNativeEntryWrapper vew;)
1777
1778 VM_LinuxDllLoad op(filename, ebuf, ebuflen);
1779 VMThread::execute(&op);
1780 if (LoadExecStackDllInVMThread) {
1781 result = op.loaded_library();
1782 }
1783 load_attempted = true;
1784 }
1785 }
1786 }
1787 }
1788
1789 if (!load_attempted) {
1790 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
1791 }
1792
1793 if (result != NULL) {
1794 // Successful loading
1795 return result;
1796 }
1797
1798 Elf32_Ehdr elf_head;
1799 int diag_msg_max_length=ebuflen-strlen(ebuf);
1800 char* diag_msg_buf=ebuf+strlen(ebuf);
1801
1802 if (diag_msg_max_length==0) {
1803 // No more space in ebuf for additional diagnostics message
1804 return NULL;
1805 }
1806
1807
1808 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1809
1810 if (file_descriptor < 0) {
1811 // Can't open library, report dlerror() message
1812 return NULL;
1813 }
1814
1815 bool failed_to_read_elf_head=
1816 (sizeof(elf_head)!=
1817 (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1818
1819 ::close(file_descriptor);
1820 if (failed_to_read_elf_head) {
1821 // file i/o error - report dlerror() msg
1822 return NULL;
1823 }
1824
1825 if (elf_head.e_ident[EI_DATA] != LITTLE_ENDIAN_ONLY(ELFDATA2LSB) BIG_ENDIAN_ONLY(ELFDATA2MSB)) {
1826 // handle invalid/out of range endianness values
1827 if (elf_head.e_ident[EI_DATA] == 0 || elf_head.e_ident[EI_DATA] > 2) {
1828 return NULL;
1829 }
1830
1831 #if defined(VM_LITTLE_ENDIAN)
1832 // VM is LE, shared object BE
1833 elf_head.e_machine = be16toh(elf_head.e_machine);
1834 #else
1835 // VM is BE, shared object LE
1836 elf_head.e_machine = le16toh(elf_head.e_machine);
1837 #endif
1838 }
1839
1840 typedef struct {
1841 Elf32_Half code; // Actual value as defined in elf.h
1842 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1843 unsigned char elf_class; // 32 or 64 bit
1844 unsigned char endianness; // MSB or LSB
1845 char* name; // String representation
1846 } arch_t;
1847
1848 #ifndef EM_486
1849 #define EM_486 6 /* Intel 80486 */
1850 #endif
1851 #ifndef EM_AARCH64
1852 #define EM_AARCH64 183 /* ARM AARCH64 */
1853 #endif
1854
1855 static const arch_t arch_array[]={
1856 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1857 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1858 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1859 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1860 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1861 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1862 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1863 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1864 #if defined(VM_LITTLE_ENDIAN)
1865 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"},
1866 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"},
1867 #else
1868 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1869 {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"},
1870 #endif
1871 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1872 // we only support 64 bit z architecture
1873 {EM_S390, EM_S390, ELFCLASS64, ELFDATA2MSB, (char*)"IBM System/390"},
1874 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1875 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1876 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1877 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1878 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"},
1879 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"},
1880 };
1881
1882 #if (defined IA32)
1883 static Elf32_Half running_arch_code=EM_386;
1884 #elif (defined AMD64) || (defined X32)
1885 static Elf32_Half running_arch_code=EM_X86_64;
1886 #elif (defined IA64)
1887 static Elf32_Half running_arch_code=EM_IA_64;
1888 #elif (defined __sparc) && (defined _LP64)
1889 static Elf32_Half running_arch_code=EM_SPARCV9;
1890 #elif (defined __sparc) && (!defined _LP64)
1891 static Elf32_Half running_arch_code=EM_SPARC;
1892 #elif (defined __powerpc64__)
1893 static Elf32_Half running_arch_code=EM_PPC64;
1894 #elif (defined __powerpc__)
1895 static Elf32_Half running_arch_code=EM_PPC;
1896 #elif (defined AARCH64)
1897 static Elf32_Half running_arch_code=EM_AARCH64;
1898 #elif (defined ARM)
1899 static Elf32_Half running_arch_code=EM_ARM;
1900 #elif (defined S390)
1901 static Elf32_Half running_arch_code=EM_S390;
1902 #elif (defined ALPHA)
1903 static Elf32_Half running_arch_code=EM_ALPHA;
1904 #elif (defined MIPSEL)
1905 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1906 #elif (defined PARISC)
1907 static Elf32_Half running_arch_code=EM_PARISC;
1908 #elif (defined MIPS)
1909 static Elf32_Half running_arch_code=EM_MIPS;
1910 #elif (defined M68K)
1911 static Elf32_Half running_arch_code=EM_68K;
1912 #elif (defined SH)
1913 static Elf32_Half running_arch_code=EM_SH;
1914 #else
1915 #error Method os::dll_load requires that one of following is defined:\
1916 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc
1917 #endif
1918
1919 // Identify compatibility class for VM's architecture and library's architecture
1920 // Obtain string descriptions for architectures
1921
1922 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1923 int running_arch_index=-1;
1924
1925 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1926 if (running_arch_code == arch_array[i].code) {
1927 running_arch_index = i;
1928 }
1929 if (lib_arch.code == arch_array[i].code) {
1930 lib_arch.compat_class = arch_array[i].compat_class;
1931 lib_arch.name = arch_array[i].name;
1932 }
1933 }
1934
1935 assert(running_arch_index != -1,
1936 "Didn't find running architecture code (running_arch_code) in arch_array");
1937 if (running_arch_index == -1) {
1938 // Even though running architecture detection failed
1939 // we may still continue with reporting dlerror() message
1940 return NULL;
1941 }
1942
1943 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1944 if (lib_arch.name != NULL) {
1945 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1946 " (Possible cause: can't load %s .so on a %s platform)",
1947 lib_arch.name, arch_array[running_arch_index].name);
1948 } else {
1949 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1950 " (Possible cause: can't load this .so (machine code=0x%x) on a %s platform)",
1951 lib_arch.code, arch_array[running_arch_index].name);
1952 }
1953 return NULL;
1954 }
1955
1956 if (lib_arch.endianness != arch_array[running_arch_index].endianness) {
1957 ::snprintf(diag_msg_buf, diag_msg_max_length-1, " (Possible cause: endianness mismatch)");
1958 return NULL;
1959 }
1960
1961 // ELF file class/capacity : 0 - invalid, 1 - 32bit, 2 - 64bit
1962 if (lib_arch.elf_class > 2 || lib_arch.elf_class < 1) {
1963 ::snprintf(diag_msg_buf, diag_msg_max_length-1, " (Possible cause: invalid ELF file class)");
1964 return NULL;
1965 }
1966
1967 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1968 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1969 " (Possible cause: architecture word width mismatch, can't load %d-bit .so on a %d-bit platform)",
1970 (int) lib_arch.elf_class * 32, arch_array[running_arch_index].elf_class * 32);
1971 return NULL;
1972 }
1973
1974 return NULL;
1975 }
1976
1977 void * os::Linux::dlopen_helper(const char *filename, char *ebuf,
1978 int ebuflen) {
1979 void * result = ::dlopen(filename, RTLD_LAZY);
1980 if (result == NULL) {
1981 const char* error_report = ::dlerror();
1982 if (error_report == NULL) {
1983 error_report = "dlerror returned no error description";
1984 }
1985 if (ebuf != NULL && ebuflen > 0) {
1986 ::strncpy(ebuf, error_report, ebuflen-1);
1987 ebuf[ebuflen-1]='\0';
1988 }
1989 Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1990 log_info(os)("shared library load of %s failed, %s", filename, error_report);
1991 } else {
1992 Events::log(NULL, "Loaded shared library %s", filename);
1993 log_info(os)("shared library load of %s was successful", filename);
1994 }
1995 return result;
1996 }
1997
1998 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf,
1999 int ebuflen) {
2000 void * result = NULL;
2001 if (LoadExecStackDllInVMThread) {
2002 result = dlopen_helper(filename, ebuf, ebuflen);
2003 }
2004
2005 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a
2006 // library that requires an executable stack, or which does not have this
2007 // stack attribute set, dlopen changes the stack attribute to executable. The
2008 // read protection of the guard pages gets lost.
2009 //
2010 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad
2011 // may have been queued at the same time.
2012
2013 if (!_stack_is_executable) {
2014 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
2015 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized
2016 jt->stack_guards_enabled()) { // No pending stack overflow exceptions
2017 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) {
2018 warning("Attempt to reguard stack yellow zone failed.");
2019 }
2020 }
2021 }
2022 }
2023
2024 return result;
2025 }
2026
2027 void* os::dll_lookup(void* handle, const char* name) {
2028 void* res = dlsym(handle, name);
2029 return res;
2030 }
2031
2032 void* os::get_default_process_handle() {
2033 return (void*)::dlopen(NULL, RTLD_LAZY);
2034 }
2035
2036 static bool _print_ascii_file(const char* filename, outputStream* st, const char* hdr = NULL) {
2037 int fd = ::open(filename, O_RDONLY);
2038 if (fd == -1) {
2039 return false;
2040 }
2041
2042 if (hdr != NULL) {
2043 st->print_cr("%s", hdr);
2044 }
2045
2046 char buf[33];
2047 int bytes;
2048 buf[32] = '\0';
2049 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) {
2050 st->print_raw(buf, bytes);
2051 }
2052
2053 ::close(fd);
2054
2055 return true;
2056 }
2057
2058 void os::print_dll_info(outputStream *st) {
2059 st->print_cr("Dynamic libraries:");
2060
2061 char fname[32];
2062 pid_t pid = os::Linux::gettid();
2063
2064 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid);
2065
2066 if (!_print_ascii_file(fname, st)) {
2067 st->print("Can not get library information for pid = %d\n", pid);
2068 }
2069 }
2070
2071 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
2072 FILE *procmapsFile = NULL;
2073
2074 // Open the procfs maps file for the current process
2075 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) {
2076 // Allocate PATH_MAX for file name plus a reasonable size for other fields.
2077 char line[PATH_MAX + 100];
2078
2079 // Read line by line from 'file'
2080 while (fgets(line, sizeof(line), procmapsFile) != NULL) {
2081 u8 base, top, offset, inode;
2082 char permissions[5];
2083 char device[6];
2084 char name[sizeof(line)];
2085
2086 // Parse fields from line
2087 int matches = sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s",
2088 &base, &top, permissions, &offset, device, &inode, name);
2089 // the last entry 'name' is empty for some entries, so we might have 6 matches instead of 7 for some lines
2090 if (matches < 6) continue;
2091 if (matches == 6) name[0] = '\0';
2092
2093 // Filter by device id '00:00' so that we only get file system mapped files.
2094 if (strcmp(device, "00:00") != 0) {
2095
2096 // Call callback with the fields of interest
2097 if(callback(name, (address)base, (address)top, param)) {
2098 // Oops abort, callback aborted
2099 fclose(procmapsFile);
2100 return 1;
2101 }
2102 }
2103 }
2104 fclose(procmapsFile);
2105 }
2106 return 0;
2107 }
2108
2109 void os::print_os_info_brief(outputStream* st) {
2110 os::Linux::print_distro_info(st);
2111
2112 os::Posix::print_uname_info(st);
2113
2114 os::Linux::print_libversion_info(st);
2115
2116 }
2117
2118 void os::print_os_info(outputStream* st) {
2119 st->print("OS:");
2120
2121 os::Linux::print_distro_info(st);
2122
2123 os::Posix::print_uname_info(st);
2124
2125 os::Linux::print_uptime_info(st);
2126
2127 // Print warning if unsafe chroot environment detected
2128 if (unsafe_chroot_detected) {
2129 st->print("WARNING!! ");
2130 st->print_cr("%s", unstable_chroot_error);
2131 }
2132
2133 os::Linux::print_libversion_info(st);
2134
2135 os::Posix::print_rlimit_info(st);
2136
2137 os::Posix::print_load_average(st);
2138
2139 os::Linux::print_full_memory_info(st);
2140
2141 os::Linux::print_proc_sys_info(st);
2142
2143 os::Linux::print_ld_preload_file(st);
2144
2145 os::Linux::print_container_info(st);
2146
2147 VM_Version::print_platform_virtualization_info(st);
2148
2149 os::Linux::print_steal_info(st);
2150 }
2151
2152 // Try to identify popular distros.
2153 // Most Linux distributions have a /etc/XXX-release file, which contains
2154 // the OS version string. Newer Linux distributions have a /etc/lsb-release
2155 // file that also contains the OS version string. Some have more than one
2156 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and
2157 // /etc/redhat-release.), so the order is important.
2158 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have
2159 // their own specific XXX-release file as well as a redhat-release file.
2160 // Because of this the XXX-release file needs to be searched for before the
2161 // redhat-release file.
2162 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the
2163 // search for redhat-release / SuSE-release needs to be before lsb-release.
2164 // Since the lsb-release file is the new standard it needs to be searched
2165 // before the older style release files.
2166 // Searching system-release (Red Hat) and os-release (other Linuxes) are a
2167 // next to last resort. The os-release file is a new standard that contains
2168 // distribution information and the system-release file seems to be an old
2169 // standard that has been replaced by the lsb-release and os-release files.
2170 // Searching for the debian_version file is the last resort. It contains
2171 // an informative string like "6.0.6" or "wheezy/sid". Because of this
2172 // "Debian " is printed before the contents of the debian_version file.
2173
2174 const char* distro_files[] = {
2175 "/etc/oracle-release",
2176 "/etc/mandriva-release",
2177 "/etc/mandrake-release",
2178 "/etc/sun-release",
2179 "/etc/redhat-release",
2180 "/etc/SuSE-release",
2181 "/etc/lsb-release",
2182 "/etc/turbolinux-release",
2183 "/etc/gentoo-release",
2184 "/etc/ltib-release",
2185 "/etc/angstrom-version",
2186 "/etc/system-release",
2187 "/etc/os-release",
2188 NULL };
2189
2190 void os::Linux::print_distro_info(outputStream* st) {
2191 for (int i = 0;; i++) {
2192 const char* file = distro_files[i];
2193 if (file == NULL) {
2194 break; // done
2195 }
2196 // If file prints, we found it.
2197 if (_print_ascii_file(file, st)) {
2198 return;
2199 }
2200 }
2201
2202 if (file_exists("/etc/debian_version")) {
2203 st->print("Debian ");
2204 _print_ascii_file("/etc/debian_version", st);
2205 } else {
2206 st->print("Linux");
2207 }
2208 st->cr();
2209 }
2210
2211 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) {
2212 char buf[256];
2213 while (fgets(buf, sizeof(buf), fp)) {
2214 // Edit out extra stuff in expected format
2215 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) {
2216 char* ptr = strstr(buf, "\""); // the name is in quotes
2217 if (ptr != NULL) {
2218 ptr++; // go beyond first quote
2219 char* nl = strchr(ptr, '\"');
2220 if (nl != NULL) *nl = '\0';
2221 strncpy(distro, ptr, length);
2222 } else {
2223 ptr = strstr(buf, "=");
2224 ptr++; // go beyond equals then
2225 char* nl = strchr(ptr, '\n');
2226 if (nl != NULL) *nl = '\0';
2227 strncpy(distro, ptr, length);
2228 }
2229 return;
2230 } else if (get_first_line) {
2231 char* nl = strchr(buf, '\n');
2232 if (nl != NULL) *nl = '\0';
2233 strncpy(distro, buf, length);
2234 return;
2235 }
2236 }
2237 // print last line and close
2238 char* nl = strchr(buf, '\n');
2239 if (nl != NULL) *nl = '\0';
2240 strncpy(distro, buf, length);
2241 }
2242
2243 static void parse_os_info(char* distro, size_t length, const char* file) {
2244 FILE* fp = fopen(file, "r");
2245 if (fp != NULL) {
2246 // if suse format, print out first line
2247 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0);
2248 parse_os_info_helper(fp, distro, length, get_first_line);
2249 fclose(fp);
2250 }
2251 }
2252
2253 void os::get_summary_os_info(char* buf, size_t buflen) {
2254 for (int i = 0;; i++) {
2255 const char* file = distro_files[i];
2256 if (file == NULL) {
2257 break; // ran out of distro_files
2258 }
2259 if (file_exists(file)) {
2260 parse_os_info(buf, buflen, file);
2261 return;
2262 }
2263 }
2264 // special case for debian
2265 if (file_exists("/etc/debian_version")) {
2266 strncpy(buf, "Debian ", buflen);
2267 if (buflen > 7) {
2268 parse_os_info(&buf[7], buflen-7, "/etc/debian_version");
2269 }
2270 } else {
2271 strncpy(buf, "Linux", buflen);
2272 }
2273 }
2274
2275 void os::Linux::print_libversion_info(outputStream* st) {
2276 // libc, pthread
2277 st->print("libc:");
2278 st->print("%s ", os::Linux::glibc_version());
2279 st->print("%s ", os::Linux::libpthread_version());
2280 st->cr();
2281 }
2282
2283 void os::Linux::print_proc_sys_info(outputStream* st) {
2284 st->cr();
2285 st->print_cr("/proc/sys/kernel/threads-max (system-wide limit on the number of threads):");
2286 _print_ascii_file("/proc/sys/kernel/threads-max", st);
2287 st->cr();
2288 st->cr();
2289
2290 st->print_cr("/proc/sys/vm/max_map_count (maximum number of memory map areas a process may have):");
2291 _print_ascii_file("/proc/sys/vm/max_map_count", st);
2292 st->cr();
2293 st->cr();
2294
2295 st->print_cr("/proc/sys/kernel/pid_max (system-wide limit on number of process identifiers):");
2296 _print_ascii_file("/proc/sys/kernel/pid_max", st);
2297 st->cr();
2298 st->cr();
2299 }
2300
2301 void os::Linux::print_full_memory_info(outputStream* st) {
2302 st->print("\n/proc/meminfo:\n");
2303 _print_ascii_file("/proc/meminfo", st);
2304 st->cr();
2305 }
2306
2307 void os::Linux::print_ld_preload_file(outputStream* st) {
2308 _print_ascii_file("/etc/ld.so.preload", st, "\n/etc/ld.so.preload:");
2309 st->cr();
2310 }
2311
2312 void os::Linux::print_uptime_info(outputStream* st) {
2313 struct sysinfo sinfo;
2314 int ret = sysinfo(&sinfo);
2315 if (ret == 0) {
2316 os::print_dhm(st, "OS uptime:", (long) sinfo.uptime);
2317 }
2318 }
2319
2320
2321 void os::Linux::print_container_info(outputStream* st) {
2322 if (!OSContainer::is_containerized()) {
2323 return;
2324 }
2325
2326 st->print("container (cgroup) information:\n");
2327
2328 const char *p_ct = OSContainer::container_type();
2329 st->print("container_type: %s\n", p_ct != NULL ? p_ct : "not supported");
2330
2331 char *p = OSContainer::cpu_cpuset_cpus();
2332 st->print("cpu_cpuset_cpus: %s\n", p != NULL ? p : "not supported");
2333 free(p);
2334
2335 p = OSContainer::cpu_cpuset_memory_nodes();
2336 st->print("cpu_memory_nodes: %s\n", p != NULL ? p : "not supported");
2337 free(p);
2338
2339 int i = OSContainer::active_processor_count();
2340 st->print("active_processor_count: ");
2341 if (i > 0) {
2342 st->print("%d\n", i);
2343 } else {
2344 st->print("not supported\n");
2345 }
2346
2347 i = OSContainer::cpu_quota();
2348 st->print("cpu_quota: ");
2349 if (i > 0) {
2350 st->print("%d\n", i);
2351 } else {
2352 st->print("%s\n", i == OSCONTAINER_ERROR ? "not supported" : "no quota");
2353 }
2354
2355 i = OSContainer::cpu_period();
2356 st->print("cpu_period: ");
2357 if (i > 0) {
2358 st->print("%d\n", i);
2359 } else {
2360 st->print("%s\n", i == OSCONTAINER_ERROR ? "not supported" : "no period");
2361 }
2362
2363 i = OSContainer::cpu_shares();
2364 st->print("cpu_shares: ");
2365 if (i > 0) {
2366 st->print("%d\n", i);
2367 } else {
2368 st->print("%s\n", i == OSCONTAINER_ERROR ? "not supported" : "no shares");
2369 }
2370
2371 jlong j = OSContainer::memory_limit_in_bytes();
2372 st->print("memory_limit_in_bytes: ");
2373 if (j > 0) {
2374 st->print(JLONG_FORMAT "\n", j);
2375 } else {
2376 st->print("%s\n", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2377 }
2378
2379 j = OSContainer::memory_and_swap_limit_in_bytes();
2380 st->print("memory_and_swap_limit_in_bytes: ");
2381 if (j > 0) {
2382 st->print(JLONG_FORMAT "\n", j);
2383 } else {
2384 st->print("%s\n", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2385 }
2386
2387 j = OSContainer::memory_soft_limit_in_bytes();
2388 st->print("memory_soft_limit_in_bytes: ");
2389 if (j > 0) {
2390 st->print(JLONG_FORMAT "\n", j);
2391 } else {
2392 st->print("%s\n", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2393 }
2394
2395 j = OSContainer::OSContainer::memory_usage_in_bytes();
2396 st->print("memory_usage_in_bytes: ");
2397 if (j > 0) {
2398 st->print(JLONG_FORMAT "\n", j);
2399 } else {
2400 st->print("%s\n", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2401 }
2402
2403 j = OSContainer::OSContainer::memory_max_usage_in_bytes();
2404 st->print("memory_max_usage_in_bytes: ");
2405 if (j > 0) {
2406 st->print(JLONG_FORMAT "\n", j);
2407 } else {
2408 st->print("%s\n", j == OSCONTAINER_ERROR ? "not supported" : "unlimited");
2409 }
2410 st->cr();
2411 }
2412
2413 void os::Linux::print_steal_info(outputStream* st) {
2414 if (has_initial_tick_info) {
2415 CPUPerfTicks pticks;
2416 bool res = os::Linux::get_tick_information(&pticks, -1);
2417
2418 if (res && pticks.has_steal_ticks) {
2419 uint64_t steal_ticks_difference = pticks.steal - initial_steal_ticks;
2420 uint64_t total_ticks_difference = pticks.total - initial_total_ticks;
2421 double steal_ticks_perc = 0.0;
2422 if (total_ticks_difference != 0) {
2423 steal_ticks_perc = (double) steal_ticks_difference / total_ticks_difference;
2424 }
2425 st->print_cr("Steal ticks since vm start: " UINT64_FORMAT, steal_ticks_difference);
2426 st->print_cr("Steal ticks percentage since vm start:%7.3f", steal_ticks_perc);
2427 }
2428 }
2429 }
2430
2431 void os::print_memory_info(outputStream* st) {
2432
2433 st->print("Memory:");
2434 st->print(" %dk page", os::vm_page_size()>>10);
2435
2436 // values in struct sysinfo are "unsigned long"
2437 struct sysinfo si;
2438 sysinfo(&si);
2439
2440 st->print(", physical " UINT64_FORMAT "k",
2441 os::physical_memory() >> 10);
2442 st->print("(" UINT64_FORMAT "k free)",
2443 os::available_memory() >> 10);
2444 st->print(", swap " UINT64_FORMAT "k",
2445 ((jlong)si.totalswap * si.mem_unit) >> 10);
2446 st->print("(" UINT64_FORMAT "k free)",
2447 ((jlong)si.freeswap * si.mem_unit) >> 10);
2448 st->cr();
2449 }
2450
2451 // Print the first "model name" line and the first "flags" line
2452 // that we find and nothing more. We assume "model name" comes
2453 // before "flags" so if we find a second "model name", then the
2454 // "flags" field is considered missing.
2455 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) {
2456 #if defined(IA32) || defined(AMD64)
2457 // Other platforms have less repetitive cpuinfo files
2458 FILE *fp = fopen("/proc/cpuinfo", "r");
2459 if (fp) {
2460 while (!feof(fp)) {
2461 if (fgets(buf, buflen, fp)) {
2462 // Assume model name comes before flags
2463 bool model_name_printed = false;
2464 if (strstr(buf, "model name") != NULL) {
2465 if (!model_name_printed) {
2466 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n");
2467 st->print_raw(buf);
2468 model_name_printed = true;
2469 } else {
2470 // model name printed but not flags? Odd, just return
2471 fclose(fp);
2472 return true;
2473 }
2474 }
2475 // print the flags line too
2476 if (strstr(buf, "flags") != NULL) {
2477 st->print_raw(buf);
2478 fclose(fp);
2479 return true;
2480 }
2481 }
2482 }
2483 fclose(fp);
2484 }
2485 #endif // x86 platforms
2486 return false;
2487 }
2488
2489 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
2490 // Only print the model name if the platform provides this as a summary
2491 if (!print_model_name_and_flags(st, buf, buflen)) {
2492 st->print("\n/proc/cpuinfo:\n");
2493 if (!_print_ascii_file("/proc/cpuinfo", st)) {
2494 st->print_cr(" <Not Available>");
2495 }
2496 }
2497 }
2498
2499 #if defined(AMD64) || defined(IA32) || defined(X32)
2500 const char* search_string = "model name";
2501 #elif defined(M68K)
2502 const char* search_string = "CPU";
2503 #elif defined(PPC64)
2504 const char* search_string = "cpu";
2505 #elif defined(S390)
2506 const char* search_string = "machine =";
2507 #elif defined(SPARC)
2508 const char* search_string = "cpu";
2509 #else
2510 const char* search_string = "Processor";
2511 #endif
2512
2513 // Parses the cpuinfo file for string representing the model name.
2514 void os::get_summary_cpu_info(char* cpuinfo, size_t length) {
2515 FILE* fp = fopen("/proc/cpuinfo", "r");
2516 if (fp != NULL) {
2517 while (!feof(fp)) {
2518 char buf[256];
2519 if (fgets(buf, sizeof(buf), fp)) {
2520 char* start = strstr(buf, search_string);
2521 if (start != NULL) {
2522 char *ptr = start + strlen(search_string);
2523 char *end = buf + strlen(buf);
2524 while (ptr != end) {
2525 // skip whitespace and colon for the rest of the name.
2526 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') {
2527 break;
2528 }
2529 ptr++;
2530 }
2531 if (ptr != end) {
2532 // reasonable string, get rid of newline and keep the rest
2533 char* nl = strchr(buf, '\n');
2534 if (nl != NULL) *nl = '\0';
2535 strncpy(cpuinfo, ptr, length);
2536 fclose(fp);
2537 return;
2538 }
2539 }
2540 }
2541 }
2542 fclose(fp);
2543 }
2544 // cpuinfo not found or parsing failed, just print generic string. The entire
2545 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86)
2546 #if defined(AARCH64)
2547 strncpy(cpuinfo, "AArch64", length);
2548 #elif defined(AMD64)
2549 strncpy(cpuinfo, "x86_64", length);
2550 #elif defined(ARM) // Order wrt. AARCH64 is relevant!
2551 strncpy(cpuinfo, "ARM", length);
2552 #elif defined(IA32)
2553 strncpy(cpuinfo, "x86_32", length);
2554 #elif defined(IA64)
2555 strncpy(cpuinfo, "IA64", length);
2556 #elif defined(PPC)
2557 strncpy(cpuinfo, "PPC64", length);
2558 #elif defined(S390)
2559 strncpy(cpuinfo, "S390", length);
2560 #elif defined(SPARC)
2561 strncpy(cpuinfo, "sparcv9", length);
2562 #elif defined(ZERO_LIBARCH)
2563 strncpy(cpuinfo, ZERO_LIBARCH, length);
2564 #else
2565 strncpy(cpuinfo, "unknown", length);
2566 #endif
2567 }
2568
2569 static void print_signal_handler(outputStream* st, int sig,
2570 char* buf, size_t buflen);
2571
2572 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
2573 st->print_cr("Signal Handlers:");
2574 print_signal_handler(st, SIGSEGV, buf, buflen);
2575 print_signal_handler(st, SIGBUS , buf, buflen);
2576 print_signal_handler(st, SIGFPE , buf, buflen);
2577 print_signal_handler(st, SIGPIPE, buf, buflen);
2578 print_signal_handler(st, SIGXFSZ, buf, buflen);
2579 print_signal_handler(st, SIGILL , buf, buflen);
2580 print_signal_handler(st, SR_signum, buf, buflen);
2581 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
2582 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
2583 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
2584 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
2585 #if defined(PPC64)
2586 print_signal_handler(st, SIGTRAP, buf, buflen);
2587 #endif
2588 }
2589
2590 static char saved_jvm_path[MAXPATHLEN] = {0};
2591
2592 // Find the full path to the current module, libjvm.so
2593 void os::jvm_path(char *buf, jint buflen) {
2594 // Error checking.
2595 if (buflen < MAXPATHLEN) {
2596 assert(false, "must use a large-enough buffer");
2597 buf[0] = '\0';
2598 return;
2599 }
2600 // Lazy resolve the path to current module.
2601 if (saved_jvm_path[0] != 0) {
2602 strcpy(buf, saved_jvm_path);
2603 return;
2604 }
2605
2606 char dli_fname[MAXPATHLEN];
2607 bool ret = dll_address_to_library_name(
2608 CAST_FROM_FN_PTR(address, os::jvm_path),
2609 dli_fname, sizeof(dli_fname), NULL);
2610 assert(ret, "cannot locate libjvm");
2611 char *rp = NULL;
2612 if (ret && dli_fname[0] != '\0') {
2613 rp = os::Posix::realpath(dli_fname, buf, buflen);
2614 }
2615 if (rp == NULL) {
2616 return;
2617 }
2618
2619 if (Arguments::sun_java_launcher_is_altjvm()) {
2620 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
2621 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
2622 // If "/jre/lib/" appears at the right place in the string, then
2623 // assume we are installed in a JDK and we're done. Otherwise, check
2624 // for a JAVA_HOME environment variable and fix up the path so it
2625 // looks like libjvm.so is installed there (append a fake suffix
2626 // hotspot/libjvm.so).
2627 const char *p = buf + strlen(buf) - 1;
2628 for (int count = 0; p > buf && count < 5; ++count) {
2629 for (--p; p > buf && *p != '/'; --p)
2630 /* empty */ ;
2631 }
2632
2633 if (strncmp(p, "/jre/lib/", 9) != 0) {
2634 // Look for JAVA_HOME in the environment.
2635 char* java_home_var = ::getenv("JAVA_HOME");
2636 if (java_home_var != NULL && java_home_var[0] != 0) {
2637 char* jrelib_p;
2638 int len;
2639
2640 // Check the current module name "libjvm.so".
2641 p = strrchr(buf, '/');
2642 if (p == NULL) {
2643 return;
2644 }
2645 assert(strstr(p, "/libjvm") == p, "invalid library name");
2646
2647 rp = os::Posix::realpath(java_home_var, buf, buflen);
2648 if (rp == NULL) {
2649 return;
2650 }
2651
2652 // determine if this is a legacy image or modules image
2653 // modules image doesn't have "jre" subdirectory
2654 len = strlen(buf);
2655 assert(len < buflen, "Ran out of buffer room");
2656 jrelib_p = buf + len;
2657 snprintf(jrelib_p, buflen-len, "/jre/lib");
2658 if (0 != access(buf, F_OK)) {
2659 snprintf(jrelib_p, buflen-len, "/lib");
2660 }
2661
2662 if (0 == access(buf, F_OK)) {
2663 // Use current module name "libjvm.so"
2664 len = strlen(buf);
2665 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
2666 } else {
2667 // Go back to path of .so
2668 rp = os::Posix::realpath(dli_fname, buf, buflen);
2669 if (rp == NULL) {
2670 return;
2671 }
2672 }
2673 }
2674 }
2675 }
2676
2677 strncpy(saved_jvm_path, buf, MAXPATHLEN);
2678 saved_jvm_path[MAXPATHLEN - 1] = '\0';
2679 }
2680
2681 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
2682 // no prefix required, not even "_"
2683 }
2684
2685 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
2686 // no suffix required
2687 }
2688
2689 ////////////////////////////////////////////////////////////////////////////////
2690 // sun.misc.Signal support
2691
2692 static void UserHandler(int sig, void *siginfo, void *context) {
2693 // Ctrl-C is pressed during error reporting, likely because the error
2694 // handler fails to abort. Let VM die immediately.
2695 if (sig == SIGINT && VMError::is_error_reported()) {
2696 os::die();
2697 }
2698
2699 os::signal_notify(sig);
2700 }
2701
2702 void* os::user_handler() {
2703 return CAST_FROM_FN_PTR(void*, UserHandler);
2704 }
2705
2706 extern "C" {
2707 typedef void (*sa_handler_t)(int);
2708 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
2709 }
2710
2711 void* os::signal(int signal_number, void* handler) {
2712 struct sigaction sigAct, oldSigAct;
2713
2714 sigfillset(&(sigAct.sa_mask));
2715 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
2716 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
2717
2718 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
2719 // -1 means registration failed
2720 return (void *)-1;
2721 }
2722
2723 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
2724 }
2725
2726 void os::signal_raise(int signal_number) {
2727 ::raise(signal_number);
2728 }
2729
2730 // The following code is moved from os.cpp for making this
2731 // code platform specific, which it is by its very nature.
2732
2733 // Will be modified when max signal is changed to be dynamic
2734 int os::sigexitnum_pd() {
2735 return NSIG;
2736 }
2737
2738 // a counter for each possible signal value
2739 static volatile jint pending_signals[NSIG+1] = { 0 };
2740
2741 // Linux(POSIX) specific hand shaking semaphore.
2742 static Semaphore* sig_sem = NULL;
2743 static PosixSemaphore sr_semaphore;
2744
2745 static void jdk_misc_signal_init() {
2746 // Initialize signal structures
2747 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2748
2749 // Initialize signal semaphore
2750 sig_sem = new Semaphore();
2751 }
2752
2753 void os::signal_notify(int sig) {
2754 if (sig_sem != NULL) {
2755 Atomic::inc(&pending_signals[sig]);
2756 sig_sem->signal();
2757 } else {
2758 // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
2759 // initialization isn't called.
2760 assert(ReduceSignalUsage, "signal semaphore should be created");
2761 }
2762 }
2763
2764 static int check_pending_signals() {
2765 for (;;) {
2766 for (int i = 0; i < NSIG + 1; i++) {
2767 jint n = pending_signals[i];
2768 if (n > 0 && n == Atomic::cmpxchg(&pending_signals[i], n, n - 1)) {
2769 return i;
2770 }
2771 }
2772 JavaThread *thread = JavaThread::current();
2773 ThreadBlockInVM tbivm(thread);
2774
2775 bool threadIsSuspended;
2776 do {
2777 thread->set_suspend_equivalent();
2778 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2779 sig_sem->wait();
2780
2781 // were we externally suspended while we were waiting?
2782 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2783 if (threadIsSuspended) {
2784 // The semaphore has been incremented, but while we were waiting
2785 // another thread suspended us. We don't want to continue running
2786 // while suspended because that would surprise the thread that
2787 // suspended us.
2788 sig_sem->signal();
2789
2790 thread->java_suspend_self();
2791 }
2792 } while (threadIsSuspended);
2793 }
2794 }
2795
2796 int os::signal_wait() {
2797 return check_pending_signals();
2798 }
2799
2800 ////////////////////////////////////////////////////////////////////////////////
2801 // Virtual Memory
2802
2803 int os::vm_page_size() {
2804 // Seems redundant as all get out
2805 assert(os::Linux::page_size() != -1, "must call os::init");
2806 return os::Linux::page_size();
2807 }
2808
2809 // Solaris allocates memory by pages.
2810 int os::vm_allocation_granularity() {
2811 assert(os::Linux::page_size() != -1, "must call os::init");
2812 return os::Linux::page_size();
2813 }
2814
2815 // Rationale behind this function:
2816 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2817 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2818 // samples for JITted code. Here we create private executable mapping over the code cache
2819 // and then we can use standard (well, almost, as mapping can change) way to provide
2820 // info for the reporting script by storing timestamp and location of symbol
2821 void linux_wrap_code(char* base, size_t size) {
2822 static volatile jint cnt = 0;
2823
2824 if (!UseOprofile) {
2825 return;
2826 }
2827
2828 char buf[PATH_MAX+1];
2829 int num = Atomic::add(&cnt, 1);
2830
2831 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d",
2832 os::get_temp_directory(), os::current_process_id(), num);
2833 unlink(buf);
2834
2835 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2836
2837 if (fd != -1) {
2838 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2839 if (rv != (off_t)-1) {
2840 if (::write(fd, "", 1) == 1) {
2841 mmap(base, size,
2842 PROT_READ|PROT_WRITE|PROT_EXEC,
2843 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2844 }
2845 }
2846 ::close(fd);
2847 unlink(buf);
2848 }
2849 }
2850
2851 static bool recoverable_mmap_error(int err) {
2852 // See if the error is one we can let the caller handle. This
2853 // list of errno values comes from JBS-6843484. I can't find a
2854 // Linux man page that documents this specific set of errno
2855 // values so while this list currently matches Solaris, it may
2856 // change as we gain experience with this failure mode.
2857 switch (err) {
2858 case EBADF:
2859 case EINVAL:
2860 case ENOTSUP:
2861 // let the caller deal with these errors
2862 return true;
2863
2864 default:
2865 // Any remaining errors on this OS can cause our reserved mapping
2866 // to be lost. That can cause confusion where different data
2867 // structures think they have the same memory mapped. The worst
2868 // scenario is if both the VM and a library think they have the
2869 // same memory mapped.
2870 return false;
2871 }
2872 }
2873
2874 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2875 int err) {
2876 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2877 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
2878 os::strerror(err), err);
2879 }
2880
2881 static void warn_fail_commit_memory(char* addr, size_t size,
2882 size_t alignment_hint, bool exec,
2883 int err) {
2884 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2885 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size,
2886 alignment_hint, exec, os::strerror(err), err);
2887 }
2888
2889 // NOTE: Linux kernel does not really reserve the pages for us.
2890 // All it does is to check if there are enough free pages
2891 // left at the time of mmap(). This could be a potential
2892 // problem.
2893 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) {
2894 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2895 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2896 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2897 if (res != (uintptr_t) MAP_FAILED) {
2898 if (UseNUMAInterleaving) {
2899 numa_make_global(addr, size);
2900 }
2901 return 0;
2902 }
2903
2904 int err = errno; // save errno from mmap() call above
2905
2906 if (!recoverable_mmap_error(err)) {
2907 warn_fail_commit_memory(addr, size, exec, err);
2908 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory.");
2909 }
2910
2911 return err;
2912 }
2913
2914 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2915 return os::Linux::commit_memory_impl(addr, size, exec) == 0;
2916 }
2917
2918 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2919 const char* mesg) {
2920 assert(mesg != NULL, "mesg must be specified");
2921 int err = os::Linux::commit_memory_impl(addr, size, exec);
2922 if (err != 0) {
2923 // the caller wants all commit errors to exit with the specified mesg:
2924 warn_fail_commit_memory(addr, size, exec, err);
2925 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2926 }
2927 }
2928
2929 // Define MAP_HUGETLB here so we can build HotSpot on old systems.
2930 #ifndef MAP_HUGETLB
2931 #define MAP_HUGETLB 0x40000
2932 #endif
2933
2934 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems.
2935 #ifndef MADV_HUGEPAGE
2936 #define MADV_HUGEPAGE 14
2937 #endif
2938
2939 int os::Linux::commit_memory_impl(char* addr, size_t size,
2940 size_t alignment_hint, bool exec) {
2941 int err = os::Linux::commit_memory_impl(addr, size, exec);
2942 if (err == 0) {
2943 realign_memory(addr, size, alignment_hint);
2944 }
2945 return err;
2946 }
2947
2948 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2949 bool exec) {
2950 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0;
2951 }
2952
2953 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2954 size_t alignment_hint, bool exec,
2955 const char* mesg) {
2956 assert(mesg != NULL, "mesg must be specified");
2957 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec);
2958 if (err != 0) {
2959 // the caller wants all commit errors to exit with the specified mesg:
2960 warn_fail_commit_memory(addr, size, alignment_hint, exec, err);
2961 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2962 }
2963 }
2964
2965 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2966 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) {
2967 // We don't check the return value: madvise(MADV_HUGEPAGE) may not
2968 // be supported or the memory may already be backed by huge pages.
2969 ::madvise(addr, bytes, MADV_HUGEPAGE);
2970 }
2971 }
2972
2973 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2974 // This method works by doing an mmap over an existing mmaping and effectively discarding
2975 // the existing pages. However it won't work for SHM-based large pages that cannot be
2976 // uncommitted at all. We don't do anything in this case to avoid creating a segment with
2977 // small pages on top of the SHM segment. This method always works for small pages, so we
2978 // allow that in any case.
2979 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) {
2980 commit_memory(addr, bytes, alignment_hint, !ExecMem);
2981 }
2982 }
2983
2984 void os::numa_make_global(char *addr, size_t bytes) {
2985 Linux::numa_interleave_memory(addr, bytes);
2986 }
2987
2988 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the
2989 // bind policy to MPOL_PREFERRED for the current thread.
2990 #define USE_MPOL_PREFERRED 0
2991
2992 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2993 // To make NUMA and large pages more robust when both enabled, we need to ease
2994 // the requirements on where the memory should be allocated. MPOL_BIND is the
2995 // default policy and it will force memory to be allocated on the specified
2996 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on
2997 // the specified node, but will not force it. Using this policy will prevent
2998 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no
2999 // free large pages.
3000 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED);
3001 Linux::numa_tonode_memory(addr, bytes, lgrp_hint);
3002 }
3003
3004 bool os::numa_topology_changed() { return false; }
3005
3006 size_t os::numa_get_groups_num() {
3007 // Return just the number of nodes in which it's possible to allocate memory
3008 // (in numa terminology, configured nodes).
3009 return Linux::numa_num_configured_nodes();
3010 }
3011
3012 int os::numa_get_group_id() {
3013 int cpu_id = Linux::sched_getcpu();
3014 if (cpu_id != -1) {
3015 int lgrp_id = Linux::get_node_by_cpu(cpu_id);
3016 if (lgrp_id != -1) {
3017 return lgrp_id;
3018 }
3019 }
3020 return 0;
3021 }
3022
3023 int os::numa_get_group_id_for_address(const void* address) {
3024 void** pages = const_cast<void**>(&address);
3025 int id = -1;
3026
3027 if (os::Linux::numa_move_pages(0, 1, pages, NULL, &id, 0) == -1) {
3028 return -1;
3029 }
3030 if (id < 0) {
3031 return -1;
3032 }
3033 return id;
3034 }
3035
3036 int os::Linux::get_existing_num_nodes() {
3037 int node;
3038 int highest_node_number = Linux::numa_max_node();
3039 int num_nodes = 0;
3040
3041 // Get the total number of nodes in the system including nodes without memory.
3042 for (node = 0; node <= highest_node_number; node++) {
3043 if (is_node_in_existing_nodes(node)) {
3044 num_nodes++;
3045 }
3046 }
3047 return num_nodes;
3048 }
3049
3050 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
3051 int highest_node_number = Linux::numa_max_node();
3052 size_t i = 0;
3053
3054 // Map all node ids in which it is possible to allocate memory. Also nodes are
3055 // not always consecutively available, i.e. available from 0 to the highest
3056 // node number. If the nodes have been bound explicitly using numactl membind,
3057 // then allocate memory from those nodes only.
3058 for (int node = 0; node <= highest_node_number; node++) {
3059 if (Linux::is_node_in_bound_nodes((unsigned int)node)) {
3060 ids[i++] = node;
3061 }
3062 }
3063 return i;
3064 }
3065
3066 bool os::get_page_info(char *start, page_info* info) {
3067 return false;
3068 }
3069
3070 char *os::scan_pages(char *start, char* end, page_info* page_expected,
3071 page_info* page_found) {
3072 return end;
3073 }
3074
3075
3076 int os::Linux::sched_getcpu_syscall(void) {
3077 unsigned int cpu = 0;
3078 int retval = -1;
3079
3080 #if defined(IA32)
3081 #ifndef SYS_getcpu
3082 #define SYS_getcpu 318
3083 #endif
3084 retval = syscall(SYS_getcpu, &cpu, NULL, NULL);
3085 #elif defined(AMD64)
3086 // Unfortunately we have to bring all these macros here from vsyscall.h
3087 // to be able to compile on old linuxes.
3088 #define __NR_vgetcpu 2
3089 #define VSYSCALL_START (-10UL << 20)
3090 #define VSYSCALL_SIZE 1024
3091 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
3092 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache);
3093 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu);
3094 retval = vgetcpu(&cpu, NULL, NULL);
3095 #endif
3096
3097 return (retval == -1) ? retval : cpu;
3098 }
3099
3100 void os::Linux::sched_getcpu_init() {
3101 // sched_getcpu() should be in libc.
3102 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
3103 dlsym(RTLD_DEFAULT, "sched_getcpu")));
3104
3105 // If it's not, try a direct syscall.
3106 if (sched_getcpu() == -1) {
3107 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
3108 (void*)&sched_getcpu_syscall));
3109 }
3110
3111 if (sched_getcpu() == -1) {
3112 vm_exit_during_initialization("getcpu(2) system call not supported by kernel");
3113 }
3114 }
3115
3116 // Something to do with the numa-aware allocator needs these symbols
3117 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { }
3118 extern "C" JNIEXPORT void numa_error(char *where) { }
3119
3120 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails
3121 // load symbol from base version instead.
3122 void* os::Linux::libnuma_dlsym(void* handle, const char *name) {
3123 void *f = dlvsym(handle, name, "libnuma_1.1");
3124 if (f == NULL) {
3125 f = dlsym(handle, name);
3126 }
3127 return f;
3128 }
3129
3130 // Handle request to load libnuma symbol version 1.2 (API v2) only.
3131 // Return NULL if the symbol is not defined in this particular version.
3132 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) {
3133 return dlvsym(handle, name, "libnuma_1.2");
3134 }
3135
3136 bool os::Linux::libnuma_init() {
3137 if (sched_getcpu() != -1) { // Requires sched_getcpu() support
3138 void *handle = dlopen("libnuma.so.1", RTLD_LAZY);
3139 if (handle != NULL) {
3140 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t,
3141 libnuma_dlsym(handle, "numa_node_to_cpus")));
3142 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t,
3143 libnuma_dlsym(handle, "numa_max_node")));
3144 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t,
3145 libnuma_dlsym(handle, "numa_num_configured_nodes")));
3146 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t,
3147 libnuma_dlsym(handle, "numa_available")));
3148 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t,
3149 libnuma_dlsym(handle, "numa_tonode_memory")));
3150 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t,
3151 libnuma_dlsym(handle, "numa_interleave_memory")));
3152 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t,
3153 libnuma_v2_dlsym(handle, "numa_interleave_memory")));
3154 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t,
3155 libnuma_dlsym(handle, "numa_set_bind_policy")));
3156 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t,
3157 libnuma_dlsym(handle, "numa_bitmask_isbitset")));
3158 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t,
3159 libnuma_dlsym(handle, "numa_distance")));
3160 set_numa_get_membind(CAST_TO_FN_PTR(numa_get_membind_func_t,
3161 libnuma_v2_dlsym(handle, "numa_get_membind")));
3162 set_numa_get_interleave_mask(CAST_TO_FN_PTR(numa_get_interleave_mask_func_t,
3163 libnuma_v2_dlsym(handle, "numa_get_interleave_mask")));
3164 set_numa_move_pages(CAST_TO_FN_PTR(numa_move_pages_func_t,
3165 libnuma_dlsym(handle, "numa_move_pages")));
3166 set_numa_set_preferred(CAST_TO_FN_PTR(numa_set_preferred_func_t,
3167 libnuma_dlsym(handle, "numa_set_preferred")));
3168
3169 if (numa_available() != -1) {
3170 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes"));
3171 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr"));
3172 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr"));
3173 set_numa_interleave_bitmask(_numa_get_interleave_mask());
3174 set_numa_membind_bitmask(_numa_get_membind());
3175 // Create an index -> node mapping, since nodes are not always consecutive
3176 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
3177 rebuild_nindex_to_node_map();
3178 // Create a cpu -> node mapping
3179 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
3180 rebuild_cpu_to_node_map();
3181 return true;
3182 }
3183 }
3184 }
3185 return false;
3186 }
3187
3188 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
3189 // Creating guard page is very expensive. Java thread has HotSpot
3190 // guard pages, only enable glibc guard page for non-Java threads.
3191 // (Remember: compiler thread is a Java thread, too!)
3192 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size());
3193 }
3194
3195 void os::Linux::rebuild_nindex_to_node_map() {
3196 int highest_node_number = Linux::numa_max_node();
3197
3198 nindex_to_node()->clear();
3199 for (int node = 0; node <= highest_node_number; node++) {
3200 if (Linux::is_node_in_existing_nodes(node)) {
3201 nindex_to_node()->append(node);
3202 }
3203 }
3204 }
3205
3206 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id.
3207 // The table is later used in get_node_by_cpu().
3208 void os::Linux::rebuild_cpu_to_node_map() {
3209 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure
3210 // in libnuma (possible values are starting from 16,
3211 // and continuing up with every other power of 2, but less
3212 // than the maximum number of CPUs supported by kernel), and
3213 // is a subject to change (in libnuma version 2 the requirements
3214 // are more reasonable) we'll just hardcode the number they use
3215 // in the library.
3216 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT;
3217
3218 size_t cpu_num = processor_count();
3219 size_t cpu_map_size = NCPUS / BitsPerCLong;
3220 size_t cpu_map_valid_size =
3221 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size);
3222
3223 cpu_to_node()->clear();
3224 cpu_to_node()->at_grow(cpu_num - 1);
3225
3226 size_t node_num = get_existing_num_nodes();
3227
3228 int distance = 0;
3229 int closest_distance = INT_MAX;
3230 int closest_node = 0;
3231 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal);
3232 for (size_t i = 0; i < node_num; i++) {
3233 // Check if node is configured (not a memory-less node). If it is not, find
3234 // the closest configured node. Check also if node is bound, i.e. it's allowed
3235 // to allocate memory from the node. If it's not allowed, map cpus in that node
3236 // to the closest node from which memory allocation is allowed.
3237 if (!is_node_in_configured_nodes(nindex_to_node()->at(i)) ||
3238 !is_node_in_bound_nodes(nindex_to_node()->at(i))) {
3239 closest_distance = INT_MAX;
3240 // Check distance from all remaining nodes in the system. Ignore distance
3241 // from itself, from another non-configured node, and from another non-bound
3242 // node.
3243 for (size_t m = 0; m < node_num; m++) {
3244 if (m != i &&
3245 is_node_in_configured_nodes(nindex_to_node()->at(m)) &&
3246 is_node_in_bound_nodes(nindex_to_node()->at(m))) {
3247 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m));
3248 // If a closest node is found, update. There is always at least one
3249 // configured and bound node in the system so there is always at least
3250 // one node close.
3251 if (distance != 0 && distance < closest_distance) {
3252 closest_distance = distance;
3253 closest_node = nindex_to_node()->at(m);
3254 }
3255 }
3256 }
3257 } else {
3258 // Current node is already a configured node.
3259 closest_node = nindex_to_node()->at(i);
3260 }
3261
3262 // Get cpus from the original node and map them to the closest node. If node
3263 // is a configured node (not a memory-less node), then original node and
3264 // closest node are the same.
3265 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) {
3266 for (size_t j = 0; j < cpu_map_valid_size; j++) {
3267 if (cpu_map[j] != 0) {
3268 for (size_t k = 0; k < BitsPerCLong; k++) {
3269 if (cpu_map[j] & (1UL << k)) {
3270 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node);
3271 }
3272 }
3273 }
3274 }
3275 }
3276 }
3277 FREE_C_HEAP_ARRAY(unsigned long, cpu_map);
3278 }
3279
3280 int os::Linux::get_node_by_cpu(int cpu_id) {
3281 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) {
3282 return cpu_to_node()->at(cpu_id);
3283 }
3284 return -1;
3285 }
3286
3287 GrowableArray<int>* os::Linux::_cpu_to_node;
3288 GrowableArray<int>* os::Linux::_nindex_to_node;
3289 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu;
3290 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus;
3291 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node;
3292 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes;
3293 os::Linux::numa_available_func_t os::Linux::_numa_available;
3294 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory;
3295 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory;
3296 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2;
3297 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy;
3298 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset;
3299 os::Linux::numa_distance_func_t os::Linux::_numa_distance;
3300 os::Linux::numa_get_membind_func_t os::Linux::_numa_get_membind;
3301 os::Linux::numa_get_interleave_mask_func_t os::Linux::_numa_get_interleave_mask;
3302 os::Linux::numa_move_pages_func_t os::Linux::_numa_move_pages;
3303 os::Linux::numa_set_preferred_func_t os::Linux::_numa_set_preferred;
3304 os::Linux::NumaAllocationPolicy os::Linux::_current_numa_policy;
3305 unsigned long* os::Linux::_numa_all_nodes;
3306 struct bitmask* os::Linux::_numa_all_nodes_ptr;
3307 struct bitmask* os::Linux::_numa_nodes_ptr;
3308 struct bitmask* os::Linux::_numa_interleave_bitmask;
3309 struct bitmask* os::Linux::_numa_membind_bitmask;
3310
3311 bool os::pd_uncommit_memory(char* addr, size_t size) {
3312 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
3313 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
3314 return res != (uintptr_t) MAP_FAILED;
3315 }
3316
3317 static address get_stack_commited_bottom(address bottom, size_t size) {
3318 address nbot = bottom;
3319 address ntop = bottom + size;
3320
3321 size_t page_sz = os::vm_page_size();
3322 unsigned pages = size / page_sz;
3323
3324 unsigned char vec[1];
3325 unsigned imin = 1, imax = pages + 1, imid;
3326 int mincore_return_value = 0;
3327
3328 assert(imin <= imax, "Unexpected page size");
3329
3330 while (imin < imax) {
3331 imid = (imax + imin) / 2;
3332 nbot = ntop - (imid * page_sz);
3333
3334 // Use a trick with mincore to check whether the page is mapped or not.
3335 // mincore sets vec to 1 if page resides in memory and to 0 if page
3336 // is swapped output but if page we are asking for is unmapped
3337 // it returns -1,ENOMEM
3338 mincore_return_value = mincore(nbot, page_sz, vec);
3339
3340 if (mincore_return_value == -1) {
3341 // Page is not mapped go up
3342 // to find first mapped page
3343 if (errno != EAGAIN) {
3344 assert(errno == ENOMEM, "Unexpected mincore errno");
3345 imax = imid;
3346 }
3347 } else {
3348 // Page is mapped go down
3349 // to find first not mapped page
3350 imin = imid + 1;
3351 }
3352 }
3353
3354 nbot = nbot + page_sz;
3355
3356 // Adjust stack bottom one page up if last checked page is not mapped
3357 if (mincore_return_value == -1) {
3358 nbot = nbot + page_sz;
3359 }
3360
3361 return nbot;
3362 }
3363
3364 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
3365 int mincore_return_value;
3366 const size_t stripe = 1024; // query this many pages each time
3367 unsigned char vec[stripe + 1];
3368 // set a guard
3369 vec[stripe] = 'X';
3370
3371 const size_t page_sz = os::vm_page_size();
3372 size_t pages = size / page_sz;
3373
3374 assert(is_aligned(start, page_sz), "Start address must be page aligned");
3375 assert(is_aligned(size, page_sz), "Size must be page aligned");
3376
3377 committed_start = NULL;
3378
3379 int loops = (pages + stripe - 1) / stripe;
3380 int committed_pages = 0;
3381 address loop_base = start;
3382 bool found_range = false;
3383
3384 for (int index = 0; index < loops && !found_range; index ++) {
3385 assert(pages > 0, "Nothing to do");
3386 int pages_to_query = (pages >= stripe) ? stripe : pages;
3387 pages -= pages_to_query;
3388
3389 // Get stable read
3390 while ((mincore_return_value = mincore(loop_base, pages_to_query * page_sz, vec)) == -1 && errno == EAGAIN);
3391
3392 // During shutdown, some memory goes away without properly notifying NMT,
3393 // E.g. ConcurrentGCThread/WatcherThread can exit without deleting thread object.
3394 // Bailout and return as not committed for now.
3395 if (mincore_return_value == -1 && errno == ENOMEM) {
3396 return false;
3397 }
3398
3399 assert(vec[stripe] == 'X', "overflow guard");
3400 assert(mincore_return_value == 0, "Range must be valid");
3401 // Process this stripe
3402 for (int vecIdx = 0; vecIdx < pages_to_query; vecIdx ++) {
3403 if ((vec[vecIdx] & 0x01) == 0) { // not committed
3404 // End of current contiguous region
3405 if (committed_start != NULL) {
3406 found_range = true;
3407 break;
3408 }
3409 } else { // committed
3410 // Start of region
3411 if (committed_start == NULL) {
3412 committed_start = loop_base + page_sz * vecIdx;
3413 }
3414 committed_pages ++;
3415 }
3416 }
3417
3418 loop_base += pages_to_query * page_sz;
3419 }
3420
3421 if (committed_start != NULL) {
3422 assert(committed_pages > 0, "Must have committed region");
3423 assert(committed_pages <= int(size / page_sz), "Can not commit more than it has");
3424 assert(committed_start >= start && committed_start < start + size, "Out of range");
3425 committed_size = page_sz * committed_pages;
3426 return true;
3427 } else {
3428 assert(committed_pages == 0, "Should not have committed region");
3429 return false;
3430 }
3431 }
3432
3433
3434 // Linux uses a growable mapping for the stack, and if the mapping for
3435 // the stack guard pages is not removed when we detach a thread the
3436 // stack cannot grow beyond the pages where the stack guard was
3437 // mapped. If at some point later in the process the stack expands to
3438 // that point, the Linux kernel cannot expand the stack any further
3439 // because the guard pages are in the way, and a segfault occurs.
3440 //
3441 // However, it's essential not to split the stack region by unmapping
3442 // a region (leaving a hole) that's already part of the stack mapping,
3443 // so if the stack mapping has already grown beyond the guard pages at
3444 // the time we create them, we have to truncate the stack mapping.
3445 // So, we need to know the extent of the stack mapping when
3446 // create_stack_guard_pages() is called.
3447
3448 // We only need this for stacks that are growable: at the time of
3449 // writing thread stacks don't use growable mappings (i.e. those
3450 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this
3451 // only applies to the main thread.
3452
3453 // If the (growable) stack mapping already extends beyond the point
3454 // where we're going to put our guard pages, truncate the mapping at
3455 // that point by munmap()ping it. This ensures that when we later
3456 // munmap() the guard pages we don't leave a hole in the stack
3457 // mapping. This only affects the main/primordial thread
3458
3459 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
3460 if (os::is_primordial_thread()) {
3461 // As we manually grow stack up to bottom inside create_attached_thread(),
3462 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and
3463 // we don't need to do anything special.
3464 // Check it first, before calling heavy function.
3465 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom();
3466 unsigned char vec[1];
3467
3468 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) {
3469 // Fallback to slow path on all errors, including EAGAIN
3470 stack_extent = (uintptr_t) get_stack_commited_bottom(
3471 os::Linux::initial_thread_stack_bottom(),
3472 (size_t)addr - stack_extent);
3473 }
3474
3475 if (stack_extent < (uintptr_t)addr) {
3476 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent));
3477 }
3478 }
3479
3480 return os::commit_memory(addr, size, !ExecMem);
3481 }
3482
3483 // If this is a growable mapping, remove the guard pages entirely by
3484 // munmap()ping them. If not, just call uncommit_memory(). This only
3485 // affects the main/primordial thread, but guard against future OS changes.
3486 // It's safe to always unmap guard pages for primordial thread because we
3487 // always place it right after end of the mapped region.
3488
3489 bool os::remove_stack_guard_pages(char* addr, size_t size) {
3490 uintptr_t stack_extent, stack_base;
3491
3492 if (os::is_primordial_thread()) {
3493 return ::munmap(addr, size) == 0;
3494 }
3495
3496 return os::uncommit_memory(addr, size);
3497 }
3498
3499 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
3500 // at 'requested_addr'. If there are existing memory mappings at the same
3501 // location, however, they will be overwritten. If 'fixed' is false,
3502 // 'requested_addr' is only treated as a hint, the return value may or
3503 // may not start from the requested address. Unlike Linux mmap(), this
3504 // function returns NULL to indicate failure.
3505 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
3506 char * addr;
3507 int flags;
3508
3509 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
3510 if (fixed) {
3511 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address");
3512 flags |= MAP_FIXED;
3513 }
3514
3515 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
3516 // touch an uncommitted page. Otherwise, the read/write might
3517 // succeed if we have enough swap space to back the physical page.
3518 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
3519 flags, -1, 0);
3520
3521 return addr == MAP_FAILED ? NULL : addr;
3522 }
3523
3524 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address
3525 // (req_addr != NULL) or with a given alignment.
3526 // - bytes shall be a multiple of alignment.
3527 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
3528 // - alignment sets the alignment at which memory shall be allocated.
3529 // It must be a multiple of allocation granularity.
3530 // Returns address of memory or NULL. If req_addr was not NULL, will only return
3531 // req_addr or NULL.
3532 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) {
3533
3534 size_t extra_size = bytes;
3535 if (req_addr == NULL && alignment > 0) {
3536 extra_size += alignment;
3537 }
3538
3539 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE,
3540 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
3541 -1, 0);
3542 if (start == MAP_FAILED) {
3543 start = NULL;
3544 } else {
3545 if (req_addr != NULL) {
3546 if (start != req_addr) {
3547 ::munmap(start, extra_size);
3548 start = NULL;
3549 }
3550 } else {
3551 char* const start_aligned = align_up(start, alignment);
3552 char* const end_aligned = start_aligned + bytes;
3553 char* const end = start + extra_size;
3554 if (start_aligned > start) {
3555 ::munmap(start, start_aligned - start);
3556 }
3557 if (end_aligned < end) {
3558 ::munmap(end_aligned, end - end_aligned);
3559 }
3560 start = start_aligned;
3561 }
3562 }
3563 return start;
3564 }
3565
3566 static int anon_munmap(char * addr, size_t size) {
3567 return ::munmap(addr, size) == 0;
3568 }
3569
3570 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
3571 size_t alignment_hint) {
3572 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
3573 }
3574
3575 bool os::pd_release_memory(char* addr, size_t size) {
3576 return anon_munmap(addr, size);
3577 }
3578
3579 static bool linux_mprotect(char* addr, size_t size, int prot) {
3580 // Linux wants the mprotect address argument to be page aligned.
3581 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size());
3582
3583 // According to SUSv3, mprotect() should only be used with mappings
3584 // established by mmap(), and mmap() always maps whole pages. Unaligned
3585 // 'addr' likely indicates problem in the VM (e.g. trying to change
3586 // protection of malloc'ed or statically allocated memory). Check the
3587 // caller if you hit this assert.
3588 assert(addr == bottom, "sanity check");
3589
3590 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size());
3591 Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(bottom), p2i(bottom+size), prot);
3592 return ::mprotect(bottom, size, prot) == 0;
3593 }
3594
3595 // Set protections specified
3596 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
3597 bool is_committed) {
3598 unsigned int p = 0;
3599 switch (prot) {
3600 case MEM_PROT_NONE: p = PROT_NONE; break;
3601 case MEM_PROT_READ: p = PROT_READ; break;
3602 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
3603 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
3604 default:
3605 ShouldNotReachHere();
3606 }
3607 // is_committed is unused.
3608 return linux_mprotect(addr, bytes, p);
3609 }
3610
3611 bool os::guard_memory(char* addr, size_t size) {
3612 return linux_mprotect(addr, size, PROT_NONE);
3613 }
3614
3615 bool os::unguard_memory(char* addr, size_t size) {
3616 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE);
3617 }
3618
3619 bool os::Linux::transparent_huge_pages_sanity_check(bool warn,
3620 size_t page_size) {
3621 bool result = false;
3622 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,
3623 MAP_ANONYMOUS|MAP_PRIVATE,
3624 -1, 0);
3625 if (p != MAP_FAILED) {
3626 void *aligned_p = align_up(p, page_size);
3627
3628 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0;
3629
3630 munmap(p, page_size * 2);
3631 }
3632
3633 if (warn && !result) {
3634 warning("TransparentHugePages is not supported by the operating system.");
3635 }
3636
3637 return result;
3638 }
3639
3640 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) {
3641 bool result = false;
3642 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
3643 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB,
3644 -1, 0);
3645
3646 if (p != MAP_FAILED) {
3647 // We don't know if this really is a huge page or not.
3648 FILE *fp = fopen("/proc/self/maps", "r");
3649 if (fp) {
3650 while (!feof(fp)) {
3651 char chars[257];
3652 long x = 0;
3653 if (fgets(chars, sizeof(chars), fp)) {
3654 if (sscanf(chars, "%lx-%*x", &x) == 1
3655 && x == (long)p) {
3656 if (strstr (chars, "hugepage")) {
3657 result = true;
3658 break;
3659 }
3660 }
3661 }
3662 }
3663 fclose(fp);
3664 }
3665 munmap(p, page_size);
3666 }
3667
3668 if (warn && !result) {
3669 warning("HugeTLBFS is not supported by the operating system.");
3670 }
3671
3672 return result;
3673 }
3674
3675 // From the coredump_filter documentation:
3676 //
3677 // - (bit 0) anonymous private memory
3678 // - (bit 1) anonymous shared memory
3679 // - (bit 2) file-backed private memory
3680 // - (bit 3) file-backed shared memory
3681 // - (bit 4) ELF header pages in file-backed private memory areas (it is
3682 // effective only if the bit 2 is cleared)
3683 // - (bit 5) hugetlb private memory
3684 // - (bit 6) hugetlb shared memory
3685 // - (bit 7) dax private memory
3686 // - (bit 8) dax shared memory
3687 //
3688 static void set_coredump_filter(CoredumpFilterBit bit) {
3689 FILE *f;
3690 long cdm;
3691
3692 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
3693 return;
3694 }
3695
3696 if (fscanf(f, "%lx", &cdm) != 1) {
3697 fclose(f);
3698 return;
3699 }
3700
3701 long saved_cdm = cdm;
3702 rewind(f);
3703 cdm |= bit;
3704
3705 if (cdm != saved_cdm) {
3706 fprintf(f, "%#lx", cdm);
3707 }
3708
3709 fclose(f);
3710 }
3711
3712 // Large page support
3713
3714 static size_t _large_page_size = 0;
3715
3716 size_t os::Linux::find_large_page_size() {
3717 size_t large_page_size = 0;
3718
3719 // large_page_size on Linux is used to round up heap size. x86 uses either
3720 // 2M or 4M page, depending on whether PAE (Physical Address Extensions)
3721 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use
3722 // page as large as 256M.
3723 //
3724 // Here we try to figure out page size by parsing /proc/meminfo and looking
3725 // for a line with the following format:
3726 // Hugepagesize: 2048 kB
3727 //
3728 // If we can't determine the value (e.g. /proc is not mounted, or the text
3729 // format has been changed), we'll use the largest page size supported by
3730 // the processor.
3731
3732 #ifndef ZERO
3733 large_page_size =
3734 AARCH64_ONLY(2 * M)
3735 AMD64_ONLY(2 * M)
3736 ARM32_ONLY(2 * M)
3737 IA32_ONLY(4 * M)
3738 IA64_ONLY(256 * M)
3739 PPC_ONLY(4 * M)
3740 S390_ONLY(1 * M)
3741 SPARC_ONLY(4 * M);
3742 #endif // ZERO
3743
3744 FILE *fp = fopen("/proc/meminfo", "r");
3745 if (fp) {
3746 while (!feof(fp)) {
3747 int x = 0;
3748 char buf[16];
3749 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) {
3750 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) {
3751 large_page_size = x * K;
3752 break;
3753 }
3754 } else {
3755 // skip to next line
3756 for (;;) {
3757 int ch = fgetc(fp);
3758 if (ch == EOF || ch == (int)'\n') break;
3759 }
3760 }
3761 }
3762 fclose(fp);
3763 }
3764
3765 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) {
3766 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is "
3767 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size),
3768 proper_unit_for_byte_size(large_page_size));
3769 }
3770
3771 return large_page_size;
3772 }
3773
3774 size_t os::Linux::setup_large_page_size() {
3775 _large_page_size = Linux::find_large_page_size();
3776 const size_t default_page_size = (size_t)Linux::page_size();
3777 if (_large_page_size > default_page_size) {
3778 _page_sizes[0] = _large_page_size;
3779 _page_sizes[1] = default_page_size;
3780 _page_sizes[2] = 0;
3781 }
3782
3783 return _large_page_size;
3784 }
3785
3786 bool os::Linux::setup_large_page_type(size_t page_size) {
3787 if (FLAG_IS_DEFAULT(UseHugeTLBFS) &&
3788 FLAG_IS_DEFAULT(UseSHM) &&
3789 FLAG_IS_DEFAULT(UseTransparentHugePages)) {
3790
3791 // The type of large pages has not been specified by the user.
3792
3793 // Try UseHugeTLBFS and then UseSHM.
3794 UseHugeTLBFS = UseSHM = true;
3795
3796 // Don't try UseTransparentHugePages since there are known
3797 // performance issues with it turned on. This might change in the future.
3798 UseTransparentHugePages = false;
3799 }
3800
3801 if (UseTransparentHugePages) {
3802 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages);
3803 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) {
3804 UseHugeTLBFS = false;
3805 UseSHM = false;
3806 return true;
3807 }
3808 UseTransparentHugePages = false;
3809 }
3810
3811 if (UseHugeTLBFS) {
3812 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS);
3813 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) {
3814 UseSHM = false;
3815 return true;
3816 }
3817 UseHugeTLBFS = false;
3818 }
3819
3820 return UseSHM;
3821 }
3822
3823 void os::large_page_init() {
3824 if (!UseLargePages &&
3825 !UseTransparentHugePages &&
3826 !UseHugeTLBFS &&
3827 !UseSHM) {
3828 // Not using large pages.
3829 return;
3830 }
3831
3832 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) {
3833 // The user explicitly turned off large pages.
3834 // Ignore the rest of the large pages flags.
3835 UseTransparentHugePages = false;
3836 UseHugeTLBFS = false;
3837 UseSHM = false;
3838 return;
3839 }
3840
3841 size_t large_page_size = Linux::setup_large_page_size();
3842 UseLargePages = Linux::setup_large_page_type(large_page_size);
3843
3844 set_coredump_filter(LARGEPAGES_BIT);
3845 }
3846
3847 #ifndef SHM_HUGETLB
3848 #define SHM_HUGETLB 04000
3849 #endif
3850
3851 #define shm_warning_format(format, ...) \
3852 do { \
3853 if (UseLargePages && \
3854 (!FLAG_IS_DEFAULT(UseLargePages) || \
3855 !FLAG_IS_DEFAULT(UseSHM) || \
3856 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \
3857 warning(format, __VA_ARGS__); \
3858 } \
3859 } while (0)
3860
3861 #define shm_warning(str) shm_warning_format("%s", str)
3862
3863 #define shm_warning_with_errno(str) \
3864 do { \
3865 int err = errno; \
3866 shm_warning_format(str " (error = %d)", err); \
3867 } while (0)
3868
3869 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) {
3870 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment");
3871
3872 if (!is_aligned(alignment, SHMLBA)) {
3873 assert(false, "Code below assumes that alignment is at least SHMLBA aligned");
3874 return NULL;
3875 }
3876
3877 // To ensure that we get 'alignment' aligned memory from shmat,
3878 // we pre-reserve aligned virtual memory and then attach to that.
3879
3880 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL);
3881 if (pre_reserved_addr == NULL) {
3882 // Couldn't pre-reserve aligned memory.
3883 shm_warning("Failed to pre-reserve aligned memory for shmat.");
3884 return NULL;
3885 }
3886
3887 // SHM_REMAP is needed to allow shmat to map over an existing mapping.
3888 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP);
3889
3890 if ((intptr_t)addr == -1) {
3891 int err = errno;
3892 shm_warning_with_errno("Failed to attach shared memory.");
3893
3894 assert(err != EACCES, "Unexpected error");
3895 assert(err != EIDRM, "Unexpected error");
3896 assert(err != EINVAL, "Unexpected error");
3897
3898 // Since we don't know if the kernel unmapped the pre-reserved memory area
3899 // we can't unmap it, since that would potentially unmap memory that was
3900 // mapped from other threads.
3901 return NULL;
3902 }
3903
3904 return addr;
3905 }
3906
3907 static char* shmat_at_address(int shmid, char* req_addr) {
3908 if (!is_aligned(req_addr, SHMLBA)) {
3909 assert(false, "Requested address needs to be SHMLBA aligned");
3910 return NULL;
3911 }
3912
3913 char* addr = (char*)shmat(shmid, req_addr, 0);
3914
3915 if ((intptr_t)addr == -1) {
3916 shm_warning_with_errno("Failed to attach shared memory.");
3917 return NULL;
3918 }
3919
3920 return addr;
3921 }
3922
3923 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) {
3924 // If a req_addr has been provided, we assume that the caller has already aligned the address.
3925 if (req_addr != NULL) {
3926 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size");
3927 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment");
3928 return shmat_at_address(shmid, req_addr);
3929 }
3930
3931 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically
3932 // return large page size aligned memory addresses when req_addr == NULL.
3933 // However, if the alignment is larger than the large page size, we have
3934 // to manually ensure that the memory returned is 'alignment' aligned.
3935 if (alignment > os::large_page_size()) {
3936 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size");
3937 return shmat_with_alignment(shmid, bytes, alignment);
3938 } else {
3939 return shmat_at_address(shmid, NULL);
3940 }
3941 }
3942
3943 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment,
3944 char* req_addr, bool exec) {
3945 // "exec" is passed in but not used. Creating the shared image for
3946 // the code cache doesn't have an SHM_X executable permission to check.
3947 assert(UseLargePages && UseSHM, "only for SHM large pages");
3948 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
3949 assert(is_aligned(req_addr, alignment), "Unaligned address");
3950
3951 if (!is_aligned(bytes, os::large_page_size())) {
3952 return NULL; // Fallback to small pages.
3953 }
3954
3955 // Create a large shared memory region to attach to based on size.
3956 // Currently, size is the total size of the heap.
3957 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);
3958 if (shmid == -1) {
3959 // Possible reasons for shmget failure:
3960 // 1. shmmax is too small for Java heap.
3961 // > check shmmax value: cat /proc/sys/kernel/shmmax
3962 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
3963 // 2. not enough large page memory.
3964 // > check available large pages: cat /proc/meminfo
3965 // > increase amount of large pages:
3966 // echo new_value > /proc/sys/vm/nr_hugepages
3967 // Note 1: different Linux may use different name for this property,
3968 // e.g. on Redhat AS-3 it is "hugetlb_pool".
3969 // Note 2: it's possible there's enough physical memory available but
3970 // they are so fragmented after a long run that they can't
3971 // coalesce into large pages. Try to reserve large pages when
3972 // the system is still "fresh".
3973 shm_warning_with_errno("Failed to reserve shared memory.");
3974 return NULL;
3975 }
3976
3977 // Attach to the region.
3978 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr);
3979
3980 // Remove shmid. If shmat() is successful, the actual shared memory segment
3981 // will be deleted when it's detached by shmdt() or when the process
3982 // terminates. If shmat() is not successful this will remove the shared
3983 // segment immediately.
3984 shmctl(shmid, IPC_RMID, NULL);
3985
3986 return addr;
3987 }
3988
3989 static void warn_on_large_pages_failure(char* req_addr, size_t bytes,
3990 int error) {
3991 assert(error == ENOMEM, "Only expect to fail if no memory is available");
3992
3993 bool warn_on_failure = UseLargePages &&
3994 (!FLAG_IS_DEFAULT(UseLargePages) ||
3995 !FLAG_IS_DEFAULT(UseHugeTLBFS) ||
3996 !FLAG_IS_DEFAULT(LargePageSizeInBytes));
3997
3998 if (warn_on_failure) {
3999 char msg[128];
4000 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: "
4001 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error);
4002 warning("%s", msg);
4003 }
4004 }
4005
4006 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes,
4007 char* req_addr,
4008 bool exec) {
4009 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
4010 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size");
4011 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
4012
4013 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
4014 char* addr = (char*)::mmap(req_addr, bytes, prot,
4015 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB,
4016 -1, 0);
4017
4018 if (addr == MAP_FAILED) {
4019 warn_on_large_pages_failure(req_addr, bytes, errno);
4020 return NULL;
4021 }
4022
4023 assert(is_aligned(addr, os::large_page_size()), "Must be");
4024
4025 return addr;
4026 }
4027
4028 // Reserve memory using mmap(MAP_HUGETLB).
4029 // - bytes shall be a multiple of alignment.
4030 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
4031 // - alignment sets the alignment at which memory shall be allocated.
4032 // It must be a multiple of allocation granularity.
4033 // Returns address of memory or NULL. If req_addr was not NULL, will only return
4034 // req_addr or NULL.
4035 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes,
4036 size_t alignment,
4037 char* req_addr,
4038 bool exec) {
4039 size_t large_page_size = os::large_page_size();
4040 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes");
4041
4042 assert(is_aligned(req_addr, alignment), "Must be");
4043 assert(is_aligned(bytes, alignment), "Must be");
4044
4045 // First reserve - but not commit - the address range in small pages.
4046 char* const start = anon_mmap_aligned(bytes, alignment, req_addr);
4047
4048 if (start == NULL) {
4049 return NULL;
4050 }
4051
4052 assert(is_aligned(start, alignment), "Must be");
4053
4054 char* end = start + bytes;
4055
4056 // Find the regions of the allocated chunk that can be promoted to large pages.
4057 char* lp_start = align_up(start, large_page_size);
4058 char* lp_end = align_down(end, large_page_size);
4059
4060 size_t lp_bytes = lp_end - lp_start;
4061
4062 assert(is_aligned(lp_bytes, large_page_size), "Must be");
4063
4064 if (lp_bytes == 0) {
4065 // The mapped region doesn't even span the start and the end of a large page.
4066 // Fall back to allocate a non-special area.
4067 ::munmap(start, end - start);
4068 return NULL;
4069 }
4070
4071 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
4072
4073 void* result;
4074
4075 // Commit small-paged leading area.
4076 if (start != lp_start) {
4077 result = ::mmap(start, lp_start - start, prot,
4078 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
4079 -1, 0);
4080 if (result == MAP_FAILED) {
4081 ::munmap(lp_start, end - lp_start);
4082 return NULL;
4083 }
4084 }
4085
4086 // Commit large-paged area.
4087 result = ::mmap(lp_start, lp_bytes, prot,
4088 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB,
4089 -1, 0);
4090 if (result == MAP_FAILED) {
4091 warn_on_large_pages_failure(lp_start, lp_bytes, errno);
4092 // If the mmap above fails, the large pages region will be unmapped and we
4093 // have regions before and after with small pages. Release these regions.
4094 //
4095 // | mapped | unmapped | mapped |
4096 // ^ ^ ^ ^
4097 // start lp_start lp_end end
4098 //
4099 ::munmap(start, lp_start - start);
4100 ::munmap(lp_end, end - lp_end);
4101 return NULL;
4102 }
4103
4104 // Commit small-paged trailing area.
4105 if (lp_end != end) {
4106 result = ::mmap(lp_end, end - lp_end, prot,
4107 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
4108 -1, 0);
4109 if (result == MAP_FAILED) {
4110 ::munmap(start, lp_end - start);
4111 return NULL;
4112 }
4113 }
4114
4115 return start;
4116 }
4117
4118 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes,
4119 size_t alignment,
4120 char* req_addr,
4121 bool exec) {
4122 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
4123 assert(is_aligned(req_addr, alignment), "Must be");
4124 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be");
4125 assert(is_power_of_2(os::large_page_size()), "Must be");
4126 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes");
4127
4128 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) {
4129 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec);
4130 } else {
4131 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec);
4132 }
4133 }
4134
4135 char* os::reserve_memory_special(size_t bytes, size_t alignment,
4136 char* req_addr, bool exec) {
4137 assert(UseLargePages, "only for large pages");
4138
4139 char* addr;
4140 if (UseSHM) {
4141 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec);
4142 } else {
4143 assert(UseHugeTLBFS, "must be");
4144 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec);
4145 }
4146
4147 if (addr != NULL) {
4148 if (UseNUMAInterleaving) {
4149 numa_make_global(addr, bytes);
4150 }
4151
4152 // The memory is committed
4153 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
4154 }
4155
4156 return addr;
4157 }
4158
4159 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) {
4160 // detaching the SHM segment will also delete it, see reserve_memory_special_shm()
4161 return shmdt(base) == 0;
4162 }
4163
4164 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) {
4165 return pd_release_memory(base, bytes);
4166 }
4167
4168 bool os::release_memory_special(char* base, size_t bytes) {
4169 bool res;
4170 if (MemTracker::tracking_level() > NMT_minimal) {
4171 Tracker tkr(Tracker::release);
4172 res = os::Linux::release_memory_special_impl(base, bytes);
4173 if (res) {
4174 tkr.record((address)base, bytes);
4175 }
4176
4177 } else {
4178 res = os::Linux::release_memory_special_impl(base, bytes);
4179 }
4180 return res;
4181 }
4182
4183 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) {
4184 assert(UseLargePages, "only for large pages");
4185 bool res;
4186
4187 if (UseSHM) {
4188 res = os::Linux::release_memory_special_shm(base, bytes);
4189 } else {
4190 assert(UseHugeTLBFS, "must be");
4191 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes);
4192 }
4193 return res;
4194 }
4195
4196 size_t os::large_page_size() {
4197 return _large_page_size;
4198 }
4199
4200 // With SysV SHM the entire memory region must be allocated as shared
4201 // memory.
4202 // HugeTLBFS allows application to commit large page memory on demand.
4203 // However, when committing memory with HugeTLBFS fails, the region
4204 // that was supposed to be committed will lose the old reservation
4205 // and allow other threads to steal that memory region. Because of this
4206 // behavior we can't commit HugeTLBFS memory.
4207 bool os::can_commit_large_page_memory() {
4208 return UseTransparentHugePages;
4209 }
4210
4211 bool os::can_execute_large_page_memory() {
4212 return UseTransparentHugePages || UseHugeTLBFS;
4213 }
4214
4215 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
4216 assert(file_desc >= 0, "file_desc is not valid");
4217 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
4218 if (result != NULL) {
4219 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
4220 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
4221 }
4222 }
4223 return result;
4224 }
4225
4226 // Reserve memory at an arbitrary address, only if that area is
4227 // available (and not reserved for something else).
4228
4229 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
4230 // Assert only that the size is a multiple of the page size, since
4231 // that's all that mmap requires, and since that's all we really know
4232 // about at this low abstraction level. If we need higher alignment,
4233 // we can either pass an alignment to this method or verify alignment
4234 // in one of the methods further up the call chain. See bug 5044738.
4235 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
4236
4237 // Repeatedly allocate blocks until the block is allocated at the
4238 // right spot.
4239
4240 // Linux mmap allows caller to pass an address as hint; give it a try first,
4241 // if kernel honors the hint then we can return immediately.
4242 char * addr = anon_mmap(requested_addr, bytes, false);
4243 if (addr == requested_addr) {
4244 return requested_addr;
4245 }
4246
4247 if (addr != NULL) {
4248 // mmap() is successful but it fails to reserve at the requested address
4249 anon_munmap(addr, bytes);
4250 }
4251
4252 return NULL;
4253 }
4254
4255 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
4256 void os::infinite_sleep() {
4257 while (true) { // sleep forever ...
4258 ::sleep(100); // ... 100 seconds at a time
4259 }
4260 }
4261
4262 // Used to convert frequent JVM_Yield() to nops
4263 bool os::dont_yield() {
4264 return DontYieldALot;
4265 }
4266
4267 // Linux CFS scheduler (since 2.6.23) does not guarantee sched_yield(2) will
4268 // actually give up the CPU. Since skip buddy (v2.6.28):
4269 //
4270 // * Sets the yielding task as skip buddy for current CPU's run queue.
4271 // * Picks next from run queue, if empty, picks a skip buddy (can be the yielding task).
4272 // * Clears skip buddies for this run queue (yielding task no longer a skip buddy).
4273 //
4274 // An alternative is calling os::naked_short_nanosleep with a small number to avoid
4275 // getting re-scheduled immediately.
4276 //
4277 void os::naked_yield() {
4278 sched_yield();
4279 }
4280
4281 ////////////////////////////////////////////////////////////////////////////////
4282 // thread priority support
4283
4284 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER
4285 // only supports dynamic priority, static priority must be zero. For real-time
4286 // applications, Linux supports SCHED_RR which allows static priority (1-99).
4287 // However, for large multi-threaded applications, SCHED_RR is not only slower
4288 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
4289 // of 5 runs - Sep 2005).
4290 //
4291 // The following code actually changes the niceness of kernel-thread/LWP. It
4292 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
4293 // not the entire user process, and user level threads are 1:1 mapped to kernel
4294 // threads. It has always been the case, but could change in the future. For
4295 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
4296 // It is only used when ThreadPriorityPolicy=1 and may require system level permission
4297 // (e.g., root privilege or CAP_SYS_NICE capability).
4298
4299 int os::java_to_os_priority[CriticalPriority + 1] = {
4300 19, // 0 Entry should never be used
4301
4302 4, // 1 MinPriority
4303 3, // 2
4304 2, // 3
4305
4306 1, // 4
4307 0, // 5 NormPriority
4308 -1, // 6
4309
4310 -2, // 7
4311 -3, // 8
4312 -4, // 9 NearMaxPriority
4313
4314 -5, // 10 MaxPriority
4315
4316 -5 // 11 CriticalPriority
4317 };
4318
4319 static int prio_init() {
4320 if (ThreadPriorityPolicy == 1) {
4321 if (geteuid() != 0) {
4322 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
4323 warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
4324 "e.g., being the root user. If the necessary permission is not " \
4325 "possessed, changes to priority will be silently ignored.");
4326 }
4327 }
4328 }
4329 if (UseCriticalJavaThreadPriority) {
4330 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
4331 }
4332 return 0;
4333 }
4334
4335 OSReturn os::set_native_priority(Thread* thread, int newpri) {
4336 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
4337
4338 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
4339 return (ret == 0) ? OS_OK : OS_ERR;
4340 }
4341
4342 OSReturn os::get_native_priority(const Thread* const thread,
4343 int *priority_ptr) {
4344 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
4345 *priority_ptr = java_to_os_priority[NormPriority];
4346 return OS_OK;
4347 }
4348
4349 errno = 0;
4350 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
4351 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
4352 }
4353
4354 ////////////////////////////////////////////////////////////////////////////////
4355 // suspend/resume support
4356
4357 // The low-level signal-based suspend/resume support is a remnant from the
4358 // old VM-suspension that used to be for java-suspension, safepoints etc,
4359 // within hotspot. Currently used by JFR's OSThreadSampler
4360 //
4361 // The remaining code is greatly simplified from the more general suspension
4362 // code that used to be used.
4363 //
4364 // The protocol is quite simple:
4365 // - suspend:
4366 // - sends a signal to the target thread
4367 // - polls the suspend state of the osthread using a yield loop
4368 // - target thread signal handler (SR_handler) sets suspend state
4369 // and blocks in sigsuspend until continued
4370 // - resume:
4371 // - sets target osthread state to continue
4372 // - sends signal to end the sigsuspend loop in the SR_handler
4373 //
4374 // Note that the SR_lock plays no role in this suspend/resume protocol,
4375 // but is checked for NULL in SR_handler as a thread termination indicator.
4376 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
4377 //
4378 // Note that resume_clear_context() and suspend_save_context() are needed
4379 // by SR_handler(), so that fetch_frame_from_ucontext() works,
4380 // which in part is used by:
4381 // - Forte Analyzer: AsyncGetCallTrace()
4382 // - StackBanging: get_frame_at_stack_banging_point()
4383
4384 static void resume_clear_context(OSThread *osthread) {
4385 osthread->set_ucontext(NULL);
4386 osthread->set_siginfo(NULL);
4387 }
4388
4389 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo,
4390 ucontext_t* context) {
4391 osthread->set_ucontext(context);
4392 osthread->set_siginfo(siginfo);
4393 }
4394
4395 // Handler function invoked when a thread's execution is suspended or
4396 // resumed. We have to be careful that only async-safe functions are
4397 // called here (Note: most pthread functions are not async safe and
4398 // should be avoided.)
4399 //
4400 // Note: sigwait() is a more natural fit than sigsuspend() from an
4401 // interface point of view, but sigwait() prevents the signal hander
4402 // from being run. libpthread would get very confused by not having
4403 // its signal handlers run and prevents sigwait()'s use with the
4404 // mutex granting granting signal.
4405 //
4406 // Currently only ever called on the VMThread and JavaThreads (PC sampling)
4407 //
4408 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
4409 // Save and restore errno to avoid confusing native code with EINTR
4410 // after sigsuspend.
4411 int old_errno = errno;
4412
4413 Thread* thread = Thread::current_or_null_safe();
4414 assert(thread != NULL, "Missing current thread in SR_handler");
4415
4416 // On some systems we have seen signal delivery get "stuck" until the signal
4417 // mask is changed as part of thread termination. Check that the current thread
4418 // has not already terminated (via SR_lock()) - else the following assertion
4419 // will fail because the thread is no longer a JavaThread as the ~JavaThread
4420 // destructor has completed.
4421
4422 if (thread->SR_lock() == NULL) {
4423 return;
4424 }
4425
4426 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
4427
4428 OSThread* osthread = thread->osthread();
4429
4430 os::SuspendResume::State current = osthread->sr.state();
4431 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
4432 suspend_save_context(osthread, siginfo, context);
4433
4434 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
4435 os::SuspendResume::State state = osthread->sr.suspended();
4436 if (state == os::SuspendResume::SR_SUSPENDED) {
4437 sigset_t suspend_set; // signals for sigsuspend()
4438 sigemptyset(&suspend_set);
4439 // get current set of blocked signals and unblock resume signal
4440 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
4441 sigdelset(&suspend_set, SR_signum);
4442
4443 sr_semaphore.signal();
4444 // wait here until we are resumed
4445 while (1) {
4446 sigsuspend(&suspend_set);
4447
4448 os::SuspendResume::State result = osthread->sr.running();
4449 if (result == os::SuspendResume::SR_RUNNING) {
4450 sr_semaphore.signal();
4451 break;
4452 }
4453 }
4454
4455 } else if (state == os::SuspendResume::SR_RUNNING) {
4456 // request was cancelled, continue
4457 } else {
4458 ShouldNotReachHere();
4459 }
4460
4461 resume_clear_context(osthread);
4462 } else if (current == os::SuspendResume::SR_RUNNING) {
4463 // request was cancelled, continue
4464 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
4465 // ignore
4466 } else {
4467 // ignore
4468 }
4469
4470 errno = old_errno;
4471 }
4472
4473 static int SR_initialize() {
4474 struct sigaction act;
4475 char *s;
4476
4477 // Get signal number to use for suspend/resume
4478 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
4479 int sig = ::strtol(s, 0, 10);
4480 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769.
4481 sig < NSIG) { // Must be legal signal and fit into sigflags[].
4482 SR_signum = sig;
4483 } else {
4484 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
4485 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
4486 }
4487 }
4488
4489 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
4490 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
4491
4492 sigemptyset(&SR_sigset);
4493 sigaddset(&SR_sigset, SR_signum);
4494
4495 // Set up signal handler for suspend/resume
4496 act.sa_flags = SA_RESTART|SA_SIGINFO;
4497 act.sa_handler = (void (*)(int)) SR_handler;
4498
4499 // SR_signum is blocked by default.
4500 // 4528190 - We also need to block pthread restart signal (32 on all
4501 // supported Linux platforms). Note that LinuxThreads need to block
4502 // this signal for all threads to work properly. So we don't have
4503 // to use hard-coded signal number when setting up the mask.
4504 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
4505
4506 if (sigaction(SR_signum, &act, 0) == -1) {
4507 return -1;
4508 }
4509
4510 // Save signal flag
4511 os::Linux::set_our_sigflags(SR_signum, act.sa_flags);
4512 return 0;
4513 }
4514
4515 static int sr_notify(OSThread* osthread) {
4516 int status = pthread_kill(osthread->pthread_id(), SR_signum);
4517 assert_status(status == 0, status, "pthread_kill");
4518 return status;
4519 }
4520
4521 // "Randomly" selected value for how long we want to spin
4522 // before bailing out on suspending a thread, also how often
4523 // we send a signal to a thread we want to resume
4524 static const int RANDOMLY_LARGE_INTEGER = 1000000;
4525 static const int RANDOMLY_LARGE_INTEGER2 = 100;
4526
4527 // returns true on success and false on error - really an error is fatal
4528 // but this seems the normal response to library errors
4529 static bool do_suspend(OSThread* osthread) {
4530 assert(osthread->sr.is_running(), "thread should be running");
4531 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
4532
4533 // mark as suspended and send signal
4534 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
4535 // failed to switch, state wasn't running?
4536 ShouldNotReachHere();
4537 return false;
4538 }
4539
4540 if (sr_notify(osthread) != 0) {
4541 ShouldNotReachHere();
4542 }
4543
4544 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
4545 while (true) {
4546 if (sr_semaphore.timedwait(2)) {
4547 break;
4548 } else {
4549 // timeout
4550 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
4551 if (cancelled == os::SuspendResume::SR_RUNNING) {
4552 return false;
4553 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
4554 // make sure that we consume the signal on the semaphore as well
4555 sr_semaphore.wait();
4556 break;
4557 } else {
4558 ShouldNotReachHere();
4559 return false;
4560 }
4561 }
4562 }
4563
4564 guarantee(osthread->sr.is_suspended(), "Must be suspended");
4565 return true;
4566 }
4567
4568 static void do_resume(OSThread* osthread) {
4569 assert(osthread->sr.is_suspended(), "thread should be suspended");
4570 assert(!sr_semaphore.trywait(), "invalid semaphore state");
4571
4572 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
4573 // failed to switch to WAKEUP_REQUEST
4574 ShouldNotReachHere();
4575 return;
4576 }
4577
4578 while (true) {
4579 if (sr_notify(osthread) == 0) {
4580 if (sr_semaphore.timedwait(2)) {
4581 if (osthread->sr.is_running()) {
4582 return;
4583 }
4584 }
4585 } else {
4586 ShouldNotReachHere();
4587 }
4588 }
4589
4590 guarantee(osthread->sr.is_running(), "Must be running!");
4591 }
4592
4593 ///////////////////////////////////////////////////////////////////////////////////
4594 // signal handling (except suspend/resume)
4595
4596 // This routine may be used by user applications as a "hook" to catch signals.
4597 // The user-defined signal handler must pass unrecognized signals to this
4598 // routine, and if it returns true (non-zero), then the signal handler must
4599 // return immediately. If the flag "abort_if_unrecognized" is true, then this
4600 // routine will never retun false (zero), but instead will execute a VM panic
4601 // routine kill the process.
4602 //
4603 // If this routine returns false, it is OK to call it again. This allows
4604 // the user-defined signal handler to perform checks either before or after
4605 // the VM performs its own checks. Naturally, the user code would be making
4606 // a serious error if it tried to handle an exception (such as a null check
4607 // or breakpoint) that the VM was generating for its own correct operation.
4608 //
4609 // This routine may recognize any of the following kinds of signals:
4610 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
4611 // It should be consulted by handlers for any of those signals.
4612 //
4613 // The caller of this routine must pass in the three arguments supplied
4614 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
4615 // field of the structure passed to sigaction(). This routine assumes that
4616 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
4617 //
4618 // Note that the VM will print warnings if it detects conflicting signal
4619 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
4620 //
4621 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo,
4622 siginfo_t* siginfo,
4623 void* ucontext,
4624 int abort_if_unrecognized);
4625
4626 static void signalHandler(int sig, siginfo_t* info, void* uc) {
4627 assert(info != NULL && uc != NULL, "it must be old kernel");
4628 int orig_errno = errno; // Preserve errno value over signal handler.
4629 JVM_handle_linux_signal(sig, info, uc, true);
4630 errno = orig_errno;
4631 }
4632
4633
4634 // This boolean allows users to forward their own non-matching signals
4635 // to JVM_handle_linux_signal, harmlessly.
4636 bool os::Linux::signal_handlers_are_installed = false;
4637
4638 // For signal-chaining
4639 bool os::Linux::libjsig_is_loaded = false;
4640 typedef struct sigaction *(*get_signal_t)(int);
4641 get_signal_t os::Linux::get_signal_action = NULL;
4642
4643 struct sigaction* os::Linux::get_chained_signal_action(int sig) {
4644 struct sigaction *actp = NULL;
4645
4646 if (libjsig_is_loaded) {
4647 // Retrieve the old signal handler from libjsig
4648 actp = (*get_signal_action)(sig);
4649 }
4650 if (actp == NULL) {
4651 // Retrieve the preinstalled signal handler from jvm
4652 actp = os::Posix::get_preinstalled_handler(sig);
4653 }
4654
4655 return actp;
4656 }
4657
4658 static bool call_chained_handler(struct sigaction *actp, int sig,
4659 siginfo_t *siginfo, void *context) {
4660 // Call the old signal handler
4661 if (actp->sa_handler == SIG_DFL) {
4662 // It's more reasonable to let jvm treat it as an unexpected exception
4663 // instead of taking the default action.
4664 return false;
4665 } else if (actp->sa_handler != SIG_IGN) {
4666 if ((actp->sa_flags & SA_NODEFER) == 0) {
4667 // automaticlly block the signal
4668 sigaddset(&(actp->sa_mask), sig);
4669 }
4670
4671 sa_handler_t hand = NULL;
4672 sa_sigaction_t sa = NULL;
4673 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
4674 // retrieve the chained handler
4675 if (siginfo_flag_set) {
4676 sa = actp->sa_sigaction;
4677 } else {
4678 hand = actp->sa_handler;
4679 }
4680
4681 if ((actp->sa_flags & SA_RESETHAND) != 0) {
4682 actp->sa_handler = SIG_DFL;
4683 }
4684
4685 // try to honor the signal mask
4686 sigset_t oset;
4687 sigemptyset(&oset);
4688 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
4689
4690 // call into the chained handler
4691 if (siginfo_flag_set) {
4692 (*sa)(sig, siginfo, context);
4693 } else {
4694 (*hand)(sig);
4695 }
4696
4697 // restore the signal mask
4698 pthread_sigmask(SIG_SETMASK, &oset, NULL);
4699 }
4700 // Tell jvm's signal handler the signal is taken care of.
4701 return true;
4702 }
4703
4704 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) {
4705 bool chained = false;
4706 // signal-chaining
4707 if (UseSignalChaining) {
4708 struct sigaction *actp = get_chained_signal_action(sig);
4709 if (actp != NULL) {
4710 chained = call_chained_handler(actp, sig, siginfo, context);
4711 }
4712 }
4713 return chained;
4714 }
4715
4716 // for diagnostic
4717 int sigflags[NSIG];
4718
4719 int os::Linux::get_our_sigflags(int sig) {
4720 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4721 return sigflags[sig];
4722 }
4723
4724 void os::Linux::set_our_sigflags(int sig, int flags) {
4725 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4726 if (sig > 0 && sig < NSIG) {
4727 sigflags[sig] = flags;
4728 }
4729 }
4730
4731 void os::Linux::set_signal_handler(int sig, bool set_installed) {
4732 // Check for overwrite.
4733 struct sigaction oldAct;
4734 sigaction(sig, (struct sigaction*)NULL, &oldAct);
4735
4736 void* oldhand = oldAct.sa_sigaction
4737 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4738 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4739 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
4740 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
4741 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
4742 if (AllowUserSignalHandlers || !set_installed) {
4743 // Do not overwrite; user takes responsibility to forward to us.
4744 return;
4745 } else if (UseSignalChaining) {
4746 // save the old handler in jvm
4747 os::Posix::save_preinstalled_handler(sig, oldAct);
4748 // libjsig also interposes the sigaction() call below and saves the
4749 // old sigaction on it own.
4750 } else {
4751 fatal("Encountered unexpected pre-existing sigaction handler "
4752 "%#lx for signal %d.", (long)oldhand, sig);
4753 }
4754 }
4755
4756 struct sigaction sigAct;
4757 sigfillset(&(sigAct.sa_mask));
4758 sigAct.sa_handler = SIG_DFL;
4759 if (!set_installed) {
4760 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4761 } else {
4762 sigAct.sa_sigaction = signalHandler;
4763 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
4764 }
4765 // Save flags, which are set by ours
4766 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
4767 sigflags[sig] = sigAct.sa_flags;
4768
4769 int ret = sigaction(sig, &sigAct, &oldAct);
4770 assert(ret == 0, "check");
4771
4772 void* oldhand2 = oldAct.sa_sigaction
4773 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
4774 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
4775 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
4776 }
4777
4778 // install signal handlers for signals that HotSpot needs to
4779 // handle in order to support Java-level exception handling.
4780
4781 void os::Linux::install_signal_handlers() {
4782 if (!signal_handlers_are_installed) {
4783 signal_handlers_are_installed = true;
4784
4785 // signal-chaining
4786 typedef void (*signal_setting_t)();
4787 signal_setting_t begin_signal_setting = NULL;
4788 signal_setting_t end_signal_setting = NULL;
4789 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4790 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
4791 if (begin_signal_setting != NULL) {
4792 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
4793 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
4794 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
4795 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
4796 libjsig_is_loaded = true;
4797 assert(UseSignalChaining, "should enable signal-chaining");
4798 }
4799 if (libjsig_is_loaded) {
4800 // Tell libjsig jvm is setting signal handlers
4801 (*begin_signal_setting)();
4802 }
4803
4804 set_signal_handler(SIGSEGV, true);
4805 set_signal_handler(SIGPIPE, true);
4806 set_signal_handler(SIGBUS, true);
4807 set_signal_handler(SIGILL, true);
4808 set_signal_handler(SIGFPE, true);
4809 #if defined(PPC64)
4810 set_signal_handler(SIGTRAP, true);
4811 #endif
4812 set_signal_handler(SIGXFSZ, true);
4813
4814 if (libjsig_is_loaded) {
4815 // Tell libjsig jvm finishes setting signal handlers
4816 (*end_signal_setting)();
4817 }
4818
4819 // We don't activate signal checker if libjsig is in place, we trust ourselves
4820 // and if UserSignalHandler is installed all bets are off.
4821 // Log that signal checking is off only if -verbose:jni is specified.
4822 if (CheckJNICalls) {
4823 if (libjsig_is_loaded) {
4824 log_debug(jni, resolve)("Info: libjsig is activated, all active signal checking is disabled");
4825 check_signals = false;
4826 }
4827 if (AllowUserSignalHandlers) {
4828 log_debug(jni, resolve)("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
4829 check_signals = false;
4830 }
4831 }
4832 }
4833 }
4834
4835 // This is the fastest way to get thread cpu time on Linux.
4836 // Returns cpu time (user+sys) for any thread, not only for current.
4837 // POSIX compliant clocks are implemented in the kernels 2.6.16+.
4838 // It might work on 2.6.10+ with a special kernel/glibc patch.
4839 // For reference, please, see IEEE Std 1003.1-2004:
4840 // http://www.unix.org/single_unix_specification
4841
4842 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) {
4843 struct timespec tp;
4844 int rc = os::Posix::clock_gettime(clockid, &tp);
4845 assert(rc == 0, "clock_gettime is expected to return 0 code");
4846
4847 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec;
4848 }
4849
4850 /////
4851 // glibc on Linux platform uses non-documented flag
4852 // to indicate, that some special sort of signal
4853 // trampoline is used.
4854 // We will never set this flag, and we should
4855 // ignore this flag in our diagnostic
4856 #ifdef SIGNIFICANT_SIGNAL_MASK
4857 #undef SIGNIFICANT_SIGNAL_MASK
4858 #endif
4859 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
4860
4861 static const char* get_signal_handler_name(address handler,
4862 char* buf, int buflen) {
4863 int offset = 0;
4864 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
4865 if (found) {
4866 // skip directory names
4867 const char *p1, *p2;
4868 p1 = buf;
4869 size_t len = strlen(os::file_separator());
4870 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
4871 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
4872 } else {
4873 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
4874 }
4875 return buf;
4876 }
4877
4878 static void print_signal_handler(outputStream* st, int sig,
4879 char* buf, size_t buflen) {
4880 struct sigaction sa;
4881
4882 sigaction(sig, NULL, &sa);
4883
4884 // See comment for SIGNIFICANT_SIGNAL_MASK define
4885 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4886
4887 st->print("%s: ", os::exception_name(sig, buf, buflen));
4888
4889 address handler = (sa.sa_flags & SA_SIGINFO)
4890 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
4891 : CAST_FROM_FN_PTR(address, sa.sa_handler);
4892
4893 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
4894 st->print("SIG_DFL");
4895 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
4896 st->print("SIG_IGN");
4897 } else {
4898 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
4899 }
4900
4901 st->print(", sa_mask[0]=");
4902 os::Posix::print_signal_set_short(st, &sa.sa_mask);
4903
4904 address rh = VMError::get_resetted_sighandler(sig);
4905 // May be, handler was resetted by VMError?
4906 if (rh != NULL) {
4907 handler = rh;
4908 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
4909 }
4910
4911 st->print(", sa_flags=");
4912 os::Posix::print_sa_flags(st, sa.sa_flags);
4913
4914 // Check: is it our handler?
4915 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
4916 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
4917 // It is our signal handler
4918 // check for flags, reset system-used one!
4919 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) {
4920 st->print(
4921 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
4922 os::Linux::get_our_sigflags(sig));
4923 }
4924 }
4925 st->cr();
4926 }
4927
4928
4929 #define DO_SIGNAL_CHECK(sig) \
4930 do { \
4931 if (!sigismember(&check_signal_done, sig)) { \
4932 os::Linux::check_signal_handler(sig); \
4933 } \
4934 } while (0)
4935
4936 // This method is a periodic task to check for misbehaving JNI applications
4937 // under CheckJNI, we can add any periodic checks here
4938
4939 void os::run_periodic_checks() {
4940 if (check_signals == false) return;
4941
4942 // SEGV and BUS if overridden could potentially prevent
4943 // generation of hs*.log in the event of a crash, debugging
4944 // such a case can be very challenging, so we absolutely
4945 // check the following for a good measure:
4946 DO_SIGNAL_CHECK(SIGSEGV);
4947 DO_SIGNAL_CHECK(SIGILL);
4948 DO_SIGNAL_CHECK(SIGFPE);
4949 DO_SIGNAL_CHECK(SIGBUS);
4950 DO_SIGNAL_CHECK(SIGPIPE);
4951 DO_SIGNAL_CHECK(SIGXFSZ);
4952 #if defined(PPC64)
4953 DO_SIGNAL_CHECK(SIGTRAP);
4954 #endif
4955
4956 // ReduceSignalUsage allows the user to override these handlers
4957 // see comments at the very top and jvm_md.h
4958 if (!ReduceSignalUsage) {
4959 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
4960 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
4961 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
4962 DO_SIGNAL_CHECK(BREAK_SIGNAL);
4963 }
4964
4965 DO_SIGNAL_CHECK(SR_signum);
4966 }
4967
4968 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
4969
4970 static os_sigaction_t os_sigaction = NULL;
4971
4972 void os::Linux::check_signal_handler(int sig) {
4973 char buf[O_BUFLEN];
4974 address jvmHandler = NULL;
4975
4976
4977 struct sigaction act;
4978 if (os_sigaction == NULL) {
4979 // only trust the default sigaction, in case it has been interposed
4980 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
4981 if (os_sigaction == NULL) return;
4982 }
4983
4984 os_sigaction(sig, (struct sigaction*)NULL, &act);
4985
4986
4987 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
4988
4989 address thisHandler = (act.sa_flags & SA_SIGINFO)
4990 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
4991 : CAST_FROM_FN_PTR(address, act.sa_handler);
4992
4993
4994 switch (sig) {
4995 case SIGSEGV:
4996 case SIGBUS:
4997 case SIGFPE:
4998 case SIGPIPE:
4999 case SIGILL:
5000 case SIGXFSZ:
5001 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
5002 break;
5003
5004 case SHUTDOWN1_SIGNAL:
5005 case SHUTDOWN2_SIGNAL:
5006 case SHUTDOWN3_SIGNAL:
5007 case BREAK_SIGNAL:
5008 jvmHandler = (address)user_handler();
5009 break;
5010
5011 default:
5012 if (sig == SR_signum) {
5013 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
5014 } else {
5015 return;
5016 }
5017 break;
5018 }
5019
5020 if (thisHandler != jvmHandler) {
5021 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
5022 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
5023 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
5024 // No need to check this sig any longer
5025 sigaddset(&check_signal_done, sig);
5026 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
5027 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
5028 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
5029 exception_name(sig, buf, O_BUFLEN));
5030 }
5031 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) {
5032 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
5033 tty->print("expected:");
5034 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig));
5035 tty->cr();
5036 tty->print(" found:");
5037 os::Posix::print_sa_flags(tty, act.sa_flags);
5038 tty->cr();
5039 // No need to check this sig any longer
5040 sigaddset(&check_signal_done, sig);
5041 }
5042
5043 // Dump all the signal
5044 if (sigismember(&check_signal_done, sig)) {
5045 print_signal_handlers(tty, buf, O_BUFLEN);
5046 }
5047 }
5048
5049 extern void report_error(char* file_name, int line_no, char* title,
5050 char* format, ...);
5051
5052 // this is called _before_ most of the global arguments have been parsed
5053 void os::init(void) {
5054 char dummy; // used to get a guess on initial stack address
5055
5056 clock_tics_per_sec = sysconf(_SC_CLK_TCK);
5057
5058 init_random(1234567);
5059
5060 Linux::set_page_size(sysconf(_SC_PAGESIZE));
5061 if (Linux::page_size() == -1) {
5062 fatal("os_linux.cpp: os::init: sysconf failed (%s)",
5063 os::strerror(errno));
5064 }
5065 init_page_sizes((size_t) Linux::page_size());
5066
5067 Linux::initialize_system_info();
5068
5069 os::Linux::CPUPerfTicks pticks;
5070 bool res = os::Linux::get_tick_information(&pticks, -1);
5071
5072 if (res && pticks.has_steal_ticks) {
5073 has_initial_tick_info = true;
5074 initial_total_ticks = pticks.total;
5075 initial_steal_ticks = pticks.steal;
5076 }
5077
5078 // _main_thread points to the thread that created/loaded the JVM.
5079 Linux::_main_thread = pthread_self();
5080
5081 // retrieve entry point for pthread_setname_np
5082 Linux::_pthread_setname_np =
5083 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np");
5084
5085 os::Posix::init();
5086
5087 initial_time_count = javaTimeNanos();
5088
5089 // Always warn if no monotonic clock available
5090 if (!os::Posix::supports_monotonic_clock()) {
5091 warning("No monotonic clock was available - timed services may " \
5092 "be adversely affected if the time-of-day clock changes");
5093 }
5094 }
5095
5096 // To install functions for atexit system call
5097 extern "C" {
5098 static void perfMemory_exit_helper() {
5099 perfMemory_exit();
5100 }
5101 }
5102
5103 void os::pd_init_container_support() {
5104 OSContainer::init();
5105 }
5106
5107 void os::Linux::numa_init() {
5108
5109 // Java can be invoked as
5110 // 1. Without numactl and heap will be allocated/configured on all nodes as
5111 // per the system policy.
5112 // 2. With numactl --interleave:
5113 // Use numa_get_interleave_mask(v2) API to get nodes bitmask. The same
5114 // API for membind case bitmask is reset.
5115 // Interleave is only hint and Kernel can fallback to other nodes if
5116 // no memory is available on the target nodes.
5117 // 3. With numactl --membind:
5118 // Use numa_get_membind(v2) API to get nodes bitmask. The same API for
5119 // interleave case returns bitmask of all nodes.
5120 // numa_all_nodes_ptr holds bitmask of all nodes.
5121 // numa_get_interleave_mask(v2) and numa_get_membind(v2) APIs returns correct
5122 // bitmask when externally configured to run on all or fewer nodes.
5123
5124 if (!Linux::libnuma_init()) {
5125 UseNUMA = false;
5126 } else {
5127 if ((Linux::numa_max_node() < 1) || Linux::is_bound_to_single_node()) {
5128 // If there's only one node (they start from 0) or if the process
5129 // is bound explicitly to a single node using membind, disable NUMA.
5130 UseNUMA = false;
5131 } else {
5132
5133 LogTarget(Info,os) log;
5134 LogStream ls(log);
5135
5136 Linux::set_configured_numa_policy(Linux::identify_numa_policy());
5137
5138 struct bitmask* bmp = Linux::_numa_membind_bitmask;
5139 const char* numa_mode = "membind";
5140
5141 if (Linux::is_running_in_interleave_mode()) {
5142 bmp = Linux::_numa_interleave_bitmask;
5143 numa_mode = "interleave";
5144 }
5145
5146 ls.print("UseNUMA is enabled and invoked in '%s' mode."
5147 " Heap will be configured using NUMA memory nodes:", numa_mode);
5148
5149 for (int node = 0; node <= Linux::numa_max_node(); node++) {
5150 if (Linux::_numa_bitmask_isbitset(bmp, node)) {
5151 ls.print(" %d", node);
5152 }
5153 }
5154 }
5155 }
5156
5157 if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) {
5158 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way
5159 // we can make the adaptive lgrp chunk resizing work. If the user specified both
5160 // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn
5161 // and disable adaptive resizing.
5162 if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) {
5163 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, "
5164 "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)");
5165 UseAdaptiveSizePolicy = false;
5166 UseAdaptiveNUMAChunkSizing = false;
5167 }
5168 }
5169
5170 if (!UseNUMA && ForceNUMA) {
5171 UseNUMA = true;
5172 }
5173 }
5174
5175 // this is called _after_ the global arguments have been parsed
5176 jint os::init_2(void) {
5177
5178 // This could be set after os::Posix::init() but all platforms
5179 // have to set it the same so we have to mirror Solaris.
5180 DEBUG_ONLY(os::set_mutex_init_done();)
5181
5182 os::Posix::init_2();
5183
5184 Linux::fast_thread_clock_init();
5185
5186 // initialize suspend/resume support - must do this before signal_sets_init()
5187 if (SR_initialize() != 0) {
5188 perror("SR_initialize failed");
5189 return JNI_ERR;
5190 }
5191
5192 Linux::signal_sets_init();
5193 Linux::install_signal_handlers();
5194 // Initialize data for jdk.internal.misc.Signal
5195 if (!ReduceSignalUsage) {
5196 jdk_misc_signal_init();
5197 }
5198
5199 if (AdjustStackSizeForTLS) {
5200 get_minstack_init();
5201 }
5202
5203 // Check and sets minimum stack sizes against command line options
5204 if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
5205 return JNI_ERR;
5206 }
5207
5208 #if defined(IA32)
5209 // Need to ensure we've determined the process's initial stack to
5210 // perform the workaround
5211 Linux::capture_initial_stack(JavaThread::stack_size_at_create());
5212 workaround_expand_exec_shield_cs_limit();
5213 #else
5214 suppress_primordial_thread_resolution = Arguments::created_by_java_launcher();
5215 if (!suppress_primordial_thread_resolution) {
5216 Linux::capture_initial_stack(JavaThread::stack_size_at_create());
5217 }
5218 #endif
5219
5220 Linux::libpthread_init();
5221 Linux::sched_getcpu_init();
5222 log_info(os)("HotSpot is running with %s, %s",
5223 Linux::glibc_version(), Linux::libpthread_version());
5224
5225 if (UseNUMA) {
5226 Linux::numa_init();
5227 }
5228
5229 if (MaxFDLimit) {
5230 // set the number of file descriptors to max. print out error
5231 // if getrlimit/setrlimit fails but continue regardless.
5232 struct rlimit nbr_files;
5233 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
5234 if (status != 0) {
5235 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
5236 } else {
5237 nbr_files.rlim_cur = nbr_files.rlim_max;
5238 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
5239 if (status != 0) {
5240 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
5241 }
5242 }
5243 }
5244
5245 // at-exit methods are called in the reverse order of their registration.
5246 // atexit functions are called on return from main or as a result of a
5247 // call to exit(3C). There can be only 32 of these functions registered
5248 // and atexit() does not set errno.
5249
5250 if (PerfAllowAtExitRegistration) {
5251 // only register atexit functions if PerfAllowAtExitRegistration is set.
5252 // atexit functions can be delayed until process exit time, which
5253 // can be problematic for embedded VM situations. Embedded VMs should
5254 // call DestroyJavaVM() to assure that VM resources are released.
5255
5256 // note: perfMemory_exit_helper atexit function may be removed in
5257 // the future if the appropriate cleanup code can be added to the
5258 // VM_Exit VMOperation's doit method.
5259 if (atexit(perfMemory_exit_helper) != 0) {
5260 warning("os::init_2 atexit(perfMemory_exit_helper) failed");
5261 }
5262 }
5263
5264 // initialize thread priority policy
5265 prio_init();
5266
5267 if (!FLAG_IS_DEFAULT(AllocateHeapAt) || !FLAG_IS_DEFAULT(AllocateOldGenAt)) {
5268 set_coredump_filter(DAX_SHARED_BIT);
5269 }
5270
5271 if (DumpPrivateMappingsInCore) {
5272 set_coredump_filter(FILE_BACKED_PVT_BIT);
5273 }
5274
5275 if (DumpSharedMappingsInCore) {
5276 set_coredump_filter(FILE_BACKED_SHARED_BIT);
5277 }
5278
5279 return JNI_OK;
5280 }
5281
5282 // Mark the polling page as unreadable
5283 void os::make_polling_page_unreadable(void) {
5284 if (!guard_memory((char*)_polling_page, Linux::page_size())) {
5285 fatal("Could not disable polling page");
5286 }
5287 }
5288
5289 // Mark the polling page as readable
5290 void os::make_polling_page_readable(void) {
5291 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) {
5292 fatal("Could not enable polling page");
5293 }
5294 }
5295
5296 // older glibc versions don't have this macro (which expands to
5297 // an optimized bit-counting function) so we have to roll our own
5298 #ifndef CPU_COUNT
5299
5300 static int _cpu_count(const cpu_set_t* cpus) {
5301 int count = 0;
5302 // only look up to the number of configured processors
5303 for (int i = 0; i < os::processor_count(); i++) {
5304 if (CPU_ISSET(i, cpus)) {
5305 count++;
5306 }
5307 }
5308 return count;
5309 }
5310
5311 #define CPU_COUNT(cpus) _cpu_count(cpus)
5312
5313 #endif // CPU_COUNT
5314
5315 // Get the current number of available processors for this process.
5316 // This value can change at any time during a process's lifetime.
5317 // sched_getaffinity gives an accurate answer as it accounts for cpusets.
5318 // If it appears there may be more than 1024 processors then we do a
5319 // dynamic check - see 6515172 for details.
5320 // If anything goes wrong we fallback to returning the number of online
5321 // processors - which can be greater than the number available to the process.
5322 int os::Linux::active_processor_count() {
5323 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors
5324 cpu_set_t* cpus_p = &cpus;
5325 int cpus_size = sizeof(cpu_set_t);
5326
5327 int configured_cpus = os::processor_count(); // upper bound on available cpus
5328 int cpu_count = 0;
5329
5330 // old build platforms may not support dynamic cpu sets
5331 #ifdef CPU_ALLOC
5332
5333 // To enable easy testing of the dynamic path on different platforms we
5334 // introduce a diagnostic flag: UseCpuAllocPath
5335 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) {
5336 // kernel may use a mask bigger than cpu_set_t
5337 log_trace(os)("active_processor_count: using dynamic path %s"
5338 "- configured processors: %d",
5339 UseCpuAllocPath ? "(forced) " : "",
5340 configured_cpus);
5341 cpus_p = CPU_ALLOC(configured_cpus);
5342 if (cpus_p != NULL) {
5343 cpus_size = CPU_ALLOC_SIZE(configured_cpus);
5344 // zero it just to be safe
5345 CPU_ZERO_S(cpus_size, cpus_p);
5346 }
5347 else {
5348 // failed to allocate so fallback to online cpus
5349 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
5350 log_trace(os)("active_processor_count: "
5351 "CPU_ALLOC failed (%s) - using "
5352 "online processor count: %d",
5353 os::strerror(errno), online_cpus);
5354 return online_cpus;
5355 }
5356 }
5357 else {
5358 log_trace(os)("active_processor_count: using static path - configured processors: %d",
5359 configured_cpus);
5360 }
5361 #else // CPU_ALLOC
5362 // these stubs won't be executed
5363 #define CPU_COUNT_S(size, cpus) -1
5364 #define CPU_FREE(cpus)
5365
5366 log_trace(os)("active_processor_count: only static path available - configured processors: %d",
5367 configured_cpus);
5368 #endif // CPU_ALLOC
5369
5370 // pid 0 means the current thread - which we have to assume represents the process
5371 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) {
5372 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5373 cpu_count = CPU_COUNT_S(cpus_size, cpus_p);
5374 }
5375 else {
5376 cpu_count = CPU_COUNT(cpus_p);
5377 }
5378 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count);
5379 }
5380 else {
5381 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN);
5382 warning("sched_getaffinity failed (%s)- using online processor count (%d) "
5383 "which may exceed available processors", os::strerror(errno), cpu_count);
5384 }
5385
5386 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
5387 CPU_FREE(cpus_p);
5388 }
5389
5390 assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check");
5391 return cpu_count;
5392 }
5393
5394 // Determine the active processor count from one of
5395 // three different sources:
5396 //
5397 // 1. User option -XX:ActiveProcessorCount
5398 // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN)
5399 // 3. extracted from cgroup cpu subsystem (shares and quotas)
5400 //
5401 // Option 1, if specified, will always override.
5402 // If the cgroup subsystem is active and configured, we
5403 // will return the min of the cgroup and option 2 results.
5404 // This is required since tools, such as numactl, that
5405 // alter cpu affinity do not update cgroup subsystem
5406 // cpuset configuration files.
5407 int os::active_processor_count() {
5408 // User has overridden the number of active processors
5409 if (ActiveProcessorCount > 0) {
5410 log_trace(os)("active_processor_count: "
5411 "active processor count set by user : %d",
5412 ActiveProcessorCount);
5413 return ActiveProcessorCount;
5414 }
5415
5416 int active_cpus;
5417 if (OSContainer::is_containerized()) {
5418 active_cpus = OSContainer::active_processor_count();
5419 log_trace(os)("active_processor_count: determined by OSContainer: %d",
5420 active_cpus);
5421 } else {
5422 active_cpus = os::Linux::active_processor_count();
5423 }
5424
5425 return active_cpus;
5426 }
5427
5428 uint os::processor_id() {
5429 const int id = Linux::sched_getcpu();
5430 assert(id >= 0 && id < _processor_count, "Invalid processor id");
5431 return (uint)id;
5432 }
5433
5434 void os::set_native_thread_name(const char *name) {
5435 if (Linux::_pthread_setname_np) {
5436 char buf [16]; // according to glibc manpage, 16 chars incl. '/0'
5437 snprintf(buf, sizeof(buf), "%s", name);
5438 buf[sizeof(buf) - 1] = '\0';
5439 const int rc = Linux::_pthread_setname_np(pthread_self(), buf);
5440 // ERANGE should not happen; all other errors should just be ignored.
5441 assert(rc != ERANGE, "pthread_setname_np failed");
5442 }
5443 }
5444
5445 bool os::bind_to_processor(uint processor_id) {
5446 // Not yet implemented.
5447 return false;
5448 }
5449
5450 ///
5451
5452 void os::SuspendedThreadTask::internal_do_task() {
5453 if (do_suspend(_thread->osthread())) {
5454 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
5455 do_task(context);
5456 do_resume(_thread->osthread());
5457 }
5458 }
5459
5460 ////////////////////////////////////////////////////////////////////////////////
5461 // debug support
5462
5463 bool os::find(address addr, outputStream* st) {
5464 Dl_info dlinfo;
5465 memset(&dlinfo, 0, sizeof(dlinfo));
5466 if (dladdr(addr, &dlinfo) != 0) {
5467 st->print(PTR_FORMAT ": ", p2i(addr));
5468 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
5469 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname,
5470 p2i(addr) - p2i(dlinfo.dli_saddr));
5471 } else if (dlinfo.dli_fbase != NULL) {
5472 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase));
5473 } else {
5474 st->print("<absolute address>");
5475 }
5476 if (dlinfo.dli_fname != NULL) {
5477 st->print(" in %s", dlinfo.dli_fname);
5478 }
5479 if (dlinfo.dli_fbase != NULL) {
5480 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase));
5481 }
5482 st->cr();
5483
5484 if (Verbose) {
5485 // decode some bytes around the PC
5486 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
5487 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
5488 address lowest = (address) dlinfo.dli_sname;
5489 if (!lowest) lowest = (address) dlinfo.dli_fbase;
5490 if (begin < lowest) begin = lowest;
5491 Dl_info dlinfo2;
5492 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
5493 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
5494 end = (address) dlinfo2.dli_saddr;
5495 }
5496 Disassembler::decode(begin, end, st);
5497 }
5498 return true;
5499 }
5500 return false;
5501 }
5502
5503 ////////////////////////////////////////////////////////////////////////////////
5504 // misc
5505
5506 // This does not do anything on Linux. This is basically a hook for being
5507 // able to use structured exception handling (thread-local exception filters)
5508 // on, e.g., Win32.
5509 void
5510 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
5511 JavaCallArguments* args, Thread* thread) {
5512 f(value, method, args, thread);
5513 }
5514
5515 void os::print_statistics() {
5516 }
5517
5518 bool os::message_box(const char* title, const char* message) {
5519 int i;
5520 fdStream err(defaultStream::error_fd());
5521 for (i = 0; i < 78; i++) err.print_raw("=");
5522 err.cr();
5523 err.print_raw_cr(title);
5524 for (i = 0; i < 78; i++) err.print_raw("-");
5525 err.cr();
5526 err.print_raw_cr(message);
5527 for (i = 0; i < 78; i++) err.print_raw("=");
5528 err.cr();
5529
5530 char buf[16];
5531 // Prevent process from exiting upon "read error" without consuming all CPU
5532 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
5533
5534 return buf[0] == 'y' || buf[0] == 'Y';
5535 }
5536
5537 // Is a (classpath) directory empty?
5538 bool os::dir_is_empty(const char* path) {
5539 DIR *dir = NULL;
5540 struct dirent *ptr;
5541
5542 dir = opendir(path);
5543 if (dir == NULL) return true;
5544
5545 // Scan the directory
5546 bool result = true;
5547 while (result && (ptr = readdir(dir)) != NULL) {
5548 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
5549 result = false;
5550 }
5551 }
5552 closedir(dir);
5553 return result;
5554 }
5555
5556 // This code originates from JDK's sysOpen and open64_w
5557 // from src/solaris/hpi/src/system_md.c
5558
5559 int os::open(const char *path, int oflag, int mode) {
5560 if (strlen(path) > MAX_PATH - 1) {
5561 errno = ENAMETOOLONG;
5562 return -1;
5563 }
5564
5565 // All file descriptors that are opened in the Java process and not
5566 // specifically destined for a subprocess should have the close-on-exec
5567 // flag set. If we don't set it, then careless 3rd party native code
5568 // might fork and exec without closing all appropriate file descriptors
5569 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in
5570 // turn might:
5571 //
5572 // - cause end-of-file to fail to be detected on some file
5573 // descriptors, resulting in mysterious hangs, or
5574 //
5575 // - might cause an fopen in the subprocess to fail on a system
5576 // suffering from bug 1085341.
5577 //
5578 // (Yes, the default setting of the close-on-exec flag is a Unix
5579 // design flaw)
5580 //
5581 // See:
5582 // 1085341: 32-bit stdio routines should support file descriptors >255
5583 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
5584 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
5585 //
5586 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open().
5587 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor
5588 // because it saves a system call and removes a small window where the flag
5589 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored
5590 // and we fall back to using FD_CLOEXEC (see below).
5591 #ifdef O_CLOEXEC
5592 oflag |= O_CLOEXEC;
5593 #endif
5594
5595 int fd = ::open64(path, oflag, mode);
5596 if (fd == -1) return -1;
5597
5598 //If the open succeeded, the file might still be a directory
5599 {
5600 struct stat64 buf64;
5601 int ret = ::fstat64(fd, &buf64);
5602 int st_mode = buf64.st_mode;
5603
5604 if (ret != -1) {
5605 if ((st_mode & S_IFMT) == S_IFDIR) {
5606 errno = EISDIR;
5607 ::close(fd);
5608 return -1;
5609 }
5610 } else {
5611 ::close(fd);
5612 return -1;
5613 }
5614 }
5615
5616 #ifdef FD_CLOEXEC
5617 // Validate that the use of the O_CLOEXEC flag on open above worked.
5618 // With recent kernels, we will perform this check exactly once.
5619 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
5620 if (!O_CLOEXEC_is_known_to_work) {
5621 int flags = ::fcntl(fd, F_GETFD);
5622 if (flags != -1) {
5623 if ((flags & FD_CLOEXEC) != 0)
5624 O_CLOEXEC_is_known_to_work = 1;
5625 else
5626 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
5627 }
5628 }
5629 #endif
5630
5631 return fd;
5632 }
5633
5634
5635 // create binary file, rewriting existing file if required
5636 int os::create_binary_file(const char* path, bool rewrite_existing) {
5637 int oflags = O_WRONLY | O_CREAT;
5638 if (!rewrite_existing) {
5639 oflags |= O_EXCL;
5640 }
5641 return ::open64(path, oflags, S_IREAD | S_IWRITE);
5642 }
5643
5644 // return current position of file pointer
5645 jlong os::current_file_offset(int fd) {
5646 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
5647 }
5648
5649 // move file pointer to the specified offset
5650 jlong os::seek_to_file_offset(int fd, jlong offset) {
5651 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
5652 }
5653
5654 // This code originates from JDK's sysAvailable
5655 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
5656
5657 int os::available(int fd, jlong *bytes) {
5658 jlong cur, end;
5659 int mode;
5660 struct stat64 buf64;
5661
5662 if (::fstat64(fd, &buf64) >= 0) {
5663 mode = buf64.st_mode;
5664 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
5665 int n;
5666 if (::ioctl(fd, FIONREAD, &n) >= 0) {
5667 *bytes = n;
5668 return 1;
5669 }
5670 }
5671 }
5672 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
5673 return 0;
5674 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
5675 return 0;
5676 } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
5677 return 0;
5678 }
5679 *bytes = end - cur;
5680 return 1;
5681 }
5682
5683 // Map a block of memory.
5684 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
5685 char *addr, size_t bytes, bool read_only,
5686 bool allow_exec) {
5687 int prot;
5688 int flags = MAP_PRIVATE;
5689
5690 if (read_only) {
5691 prot = PROT_READ;
5692 } else {
5693 prot = PROT_READ | PROT_WRITE;
5694 }
5695
5696 if (allow_exec) {
5697 prot |= PROT_EXEC;
5698 }
5699
5700 if (addr != NULL) {
5701 flags |= MAP_FIXED;
5702 }
5703
5704 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
5705 fd, file_offset);
5706 if (mapped_address == MAP_FAILED) {
5707 return NULL;
5708 }
5709 return mapped_address;
5710 }
5711
5712
5713 // Remap a block of memory.
5714 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
5715 char *addr, size_t bytes, bool read_only,
5716 bool allow_exec) {
5717 // same as map_memory() on this OS
5718 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
5719 allow_exec);
5720 }
5721
5722
5723 // Unmap a block of memory.
5724 bool os::pd_unmap_memory(char* addr, size_t bytes) {
5725 return munmap(addr, bytes) == 0;
5726 }
5727
5728 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time);
5729
5730 static jlong fast_cpu_time(Thread *thread) {
5731 clockid_t clockid;
5732 int rc = os::Linux::pthread_getcpuclockid(thread->osthread()->pthread_id(),
5733 &clockid);
5734 if (rc == 0) {
5735 return os::Linux::fast_thread_cpu_time(clockid);
5736 } else {
5737 // It's possible to encounter a terminated native thread that failed
5738 // to detach itself from the VM - which should result in ESRCH.
5739 assert_status(rc == ESRCH, rc, "pthread_getcpuclockid failed");
5740 return -1;
5741 }
5742 }
5743
5744 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
5745 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
5746 // of a thread.
5747 //
5748 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
5749 // the fast estimate available on the platform.
5750
5751 jlong os::current_thread_cpu_time() {
5752 if (os::Linux::supports_fast_thread_cpu_time()) {
5753 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5754 } else {
5755 // return user + sys since the cost is the same
5756 return slow_thread_cpu_time(Thread::current(), true /* user + sys */);
5757 }
5758 }
5759
5760 jlong os::thread_cpu_time(Thread* thread) {
5761 // consistent with what current_thread_cpu_time() returns
5762 if (os::Linux::supports_fast_thread_cpu_time()) {
5763 return fast_cpu_time(thread);
5764 } else {
5765 return slow_thread_cpu_time(thread, true /* user + sys */);
5766 }
5767 }
5768
5769 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
5770 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5771 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
5772 } else {
5773 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time);
5774 }
5775 }
5776
5777 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5778 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
5779 return fast_cpu_time(thread);
5780 } else {
5781 return slow_thread_cpu_time(thread, user_sys_cpu_time);
5782 }
5783 }
5784
5785 // -1 on error.
5786 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
5787 pid_t tid = thread->osthread()->thread_id();
5788 char *s;
5789 char stat[2048];
5790 int statlen;
5791 char proc_name[64];
5792 int count;
5793 long sys_time, user_time;
5794 char cdummy;
5795 int idummy;
5796 long ldummy;
5797 FILE *fp;
5798
5799 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid);
5800 fp = fopen(proc_name, "r");
5801 if (fp == NULL) return -1;
5802 statlen = fread(stat, 1, 2047, fp);
5803 stat[statlen] = '\0';
5804 fclose(fp);
5805
5806 // Skip pid and the command string. Note that we could be dealing with
5807 // weird command names, e.g. user could decide to rename java launcher
5808 // to "java 1.4.2 :)", then the stat file would look like
5809 // 1234 (java 1.4.2 :)) R ... ...
5810 // We don't really need to know the command string, just find the last
5811 // occurrence of ")" and then start parsing from there. See bug 4726580.
5812 s = strrchr(stat, ')');
5813 if (s == NULL) return -1;
5814
5815 // Skip blank chars
5816 do { s++; } while (s && isspace(*s));
5817
5818 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu",
5819 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy,
5820 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy,
5821 &user_time, &sys_time);
5822 if (count != 13) return -1;
5823 if (user_sys_cpu_time) {
5824 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
5825 } else {
5826 return (jlong)user_time * (1000000000 / clock_tics_per_sec);
5827 }
5828 }
5829
5830 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5831 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5832 info_ptr->may_skip_backward = false; // elapsed time not wall time
5833 info_ptr->may_skip_forward = false; // elapsed time not wall time
5834 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5835 }
5836
5837 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
5838 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
5839 info_ptr->may_skip_backward = false; // elapsed time not wall time
5840 info_ptr->may_skip_forward = false; // elapsed time not wall time
5841 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
5842 }
5843
5844 bool os::is_thread_cpu_time_supported() {
5845 return true;
5846 }
5847
5848 // System loadavg support. Returns -1 if load average cannot be obtained.
5849 // Linux doesn't yet have a (official) notion of processor sets,
5850 // so just return the system wide load average.
5851 int os::loadavg(double loadavg[], int nelem) {
5852 return ::getloadavg(loadavg, nelem);
5853 }
5854
5855 void os::pause() {
5856 char filename[MAX_PATH];
5857 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
5858 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
5859 } else {
5860 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
5861 }
5862
5863 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
5864 if (fd != -1) {
5865 struct stat buf;
5866 ::close(fd);
5867 while (::stat(filename, &buf) == 0) {
5868 (void)::poll(NULL, 0, 100);
5869 }
5870 } else {
5871 jio_fprintf(stderr,
5872 "Could not open pause file '%s', continuing immediately.\n", filename);
5873 }
5874 }
5875
5876 extern char** environ;
5877
5878 // Run the specified command in a separate process. Return its exit value,
5879 // or -1 on failure (e.g. can't fork a new process).
5880 // Unlike system(), this function can be called from signal handler. It
5881 // doesn't block SIGINT et al.
5882 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
5883 const char * argv[4] = {"sh", "-c", cmd, NULL};
5884
5885 pid_t pid ;
5886
5887 if (use_vfork_if_available) {
5888 pid = vfork();
5889 } else {
5890 pid = fork();
5891 }
5892
5893 if (pid < 0) {
5894 // fork failed
5895 return -1;
5896
5897 } else if (pid == 0) {
5898 // child process
5899
5900 execve("/bin/sh", (char* const*)argv, environ);
5901
5902 // execve failed
5903 _exit(-1);
5904
5905 } else {
5906 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
5907 // care about the actual exit code, for now.
5908
5909 int status;
5910
5911 // Wait for the child process to exit. This returns immediately if
5912 // the child has already exited. */
5913 while (waitpid(pid, &status, 0) < 0) {
5914 switch (errno) {
5915 case ECHILD: return 0;
5916 case EINTR: break;
5917 default: return -1;
5918 }
5919 }
5920
5921 if (WIFEXITED(status)) {
5922 // The child exited normally; get its exit code.
5923 return WEXITSTATUS(status);
5924 } else if (WIFSIGNALED(status)) {
5925 // The child exited because of a signal
5926 // The best value to return is 0x80 + signal number,
5927 // because that is what all Unix shells do, and because
5928 // it allows callers to distinguish between process exit and
5929 // process death by signal.
5930 return 0x80 + WTERMSIG(status);
5931 } else {
5932 // Unknown exit code; pass it through
5933 return status;
5934 }
5935 }
5936 }
5937
5938 // Get the default path to the core file
5939 // Returns the length of the string
5940 int os::get_core_path(char* buffer, size_t bufferSize) {
5941 /*
5942 * Max length of /proc/sys/kernel/core_pattern is 128 characters.
5943 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
5944 */
5945 const int core_pattern_len = 129;
5946 char core_pattern[core_pattern_len] = {0};
5947
5948 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY);
5949 if (core_pattern_file == -1) {
5950 return -1;
5951 }
5952
5953 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len);
5954 ::close(core_pattern_file);
5955 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') {
5956 return -1;
5957 }
5958 if (core_pattern[ret-1] == '\n') {
5959 core_pattern[ret-1] = '\0';
5960 } else {
5961 core_pattern[ret] = '\0';
5962 }
5963
5964 // Replace the %p in the core pattern with the process id. NOTE: we do this
5965 // only if the pattern doesn't start with "|", and we support only one %p in
5966 // the pattern.
5967 char *pid_pos = strstr(core_pattern, "%p");
5968 const char* tail = (pid_pos != NULL) ? (pid_pos + 2) : ""; // skip over the "%p"
5969 int written;
5970
5971 if (core_pattern[0] == '/') {
5972 if (pid_pos != NULL) {
5973 *pid_pos = '\0';
5974 written = jio_snprintf(buffer, bufferSize, "%s%d%s", core_pattern,
5975 current_process_id(), tail);
5976 } else {
5977 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern);
5978 }
5979 } else {
5980 char cwd[PATH_MAX];
5981
5982 const char* p = get_current_directory(cwd, PATH_MAX);
5983 if (p == NULL) {
5984 return -1;
5985 }
5986
5987 if (core_pattern[0] == '|') {
5988 written = jio_snprintf(buffer, bufferSize,
5989 "\"%s\" (or dumping to %s/core.%d)",
5990 &core_pattern[1], p, current_process_id());
5991 } else if (pid_pos != NULL) {
5992 *pid_pos = '\0';
5993 written = jio_snprintf(buffer, bufferSize, "%s/%s%d%s", p, core_pattern,
5994 current_process_id(), tail);
5995 } else {
5996 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern);
5997 }
5998 }
5999
6000 if (written < 0) {
6001 return -1;
6002 }
6003
6004 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) {
6005 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY);
6006
6007 if (core_uses_pid_file != -1) {
6008 char core_uses_pid = 0;
6009 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1);
6010 ::close(core_uses_pid_file);
6011
6012 if (core_uses_pid == '1') {
6013 jio_snprintf(buffer + written, bufferSize - written,
6014 ".%d", current_process_id());
6015 }
6016 }
6017 }
6018
6019 return strlen(buffer);
6020 }
6021
6022 bool os::start_debugging(char *buf, int buflen) {
6023 int len = (int)strlen(buf);
6024 char *p = &buf[len];
6025
6026 jio_snprintf(p, buflen-len,
6027 "\n\n"
6028 "Do you want to debug the problem?\n\n"
6029 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n"
6030 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
6031 "Otherwise, press RETURN to abort...",
6032 os::current_process_id(), os::current_process_id(),
6033 os::current_thread_id(), os::current_thread_id());
6034
6035 bool yes = os::message_box("Unexpected Error", buf);
6036
6037 if (yes) {
6038 // yes, user asked VM to launch debugger
6039 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d",
6040 os::current_process_id(), os::current_process_id());
6041
6042 os::fork_and_exec(buf);
6043 yes = false;
6044 }
6045 return yes;
6046 }
6047
6048
6049 // Java/Compiler thread:
6050 //
6051 // Low memory addresses
6052 // P0 +------------------------+
6053 // | |\ Java thread created by VM does not have glibc
6054 // | glibc guard page | - guard page, attached Java thread usually has
6055 // | |/ 1 glibc guard page.
6056 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
6057 // | |\
6058 // | HotSpot Guard Pages | - red, yellow and reserved pages
6059 // | |/
6060 // +------------------------+ JavaThread::stack_reserved_zone_base()
6061 // | |\
6062 // | Normal Stack | -
6063 // | |/
6064 // P2 +------------------------+ Thread::stack_base()
6065 //
6066 // Non-Java thread:
6067 //
6068 // Low memory addresses
6069 // P0 +------------------------+
6070 // | |\
6071 // | glibc guard page | - usually 1 page
6072 // | |/
6073 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
6074 // | |\
6075 // | Normal Stack | -
6076 // | |/
6077 // P2 +------------------------+ Thread::stack_base()
6078 //
6079 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size
6080 // returned from pthread_attr_getstack().
6081 // ** Due to NPTL implementation error, linux takes the glibc guard page out
6082 // of the stack size given in pthread_attr. We work around this for
6083 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.)
6084 //
6085 #ifndef ZERO
6086 static void current_stack_region(address * bottom, size_t * size) {
6087 if (os::is_primordial_thread()) {
6088 // primordial thread needs special handling because pthread_getattr_np()
6089 // may return bogus value.
6090 *bottom = os::Linux::initial_thread_stack_bottom();
6091 *size = os::Linux::initial_thread_stack_size();
6092 } else {
6093 pthread_attr_t attr;
6094
6095 int rslt = pthread_getattr_np(pthread_self(), &attr);
6096
6097 // JVM needs to know exact stack location, abort if it fails
6098 if (rslt != 0) {
6099 if (rslt == ENOMEM) {
6100 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
6101 } else {
6102 fatal("pthread_getattr_np failed with error = %d", rslt);
6103 }
6104 }
6105
6106 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
6107 fatal("Cannot locate current stack attributes!");
6108 }
6109
6110 // Work around NPTL stack guard error.
6111 size_t guard_size = 0;
6112 rslt = pthread_attr_getguardsize(&attr, &guard_size);
6113 if (rslt != 0) {
6114 fatal("pthread_attr_getguardsize failed with error = %d", rslt);
6115 }
6116 *bottom += guard_size;
6117 *size -= guard_size;
6118
6119 pthread_attr_destroy(&attr);
6120
6121 }
6122 assert(os::current_stack_pointer() >= *bottom &&
6123 os::current_stack_pointer() < *bottom + *size, "just checking");
6124 }
6125
6126 address os::current_stack_base() {
6127 address bottom;
6128 size_t size;
6129 current_stack_region(&bottom, &size);
6130 return (bottom + size);
6131 }
6132
6133 size_t os::current_stack_size() {
6134 // This stack size includes the usable stack and HotSpot guard pages
6135 // (for the threads that have Hotspot guard pages).
6136 address bottom;
6137 size_t size;
6138 current_stack_region(&bottom, &size);
6139 return size;
6140 }
6141 #endif
6142
6143 static inline struct timespec get_mtime(const char* filename) {
6144 struct stat st;
6145 int ret = os::stat(filename, &st);
6146 assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
6147 return st.st_mtim;
6148 }
6149
6150 int os::compare_file_modified_times(const char* file1, const char* file2) {
6151 struct timespec filetime1 = get_mtime(file1);
6152 struct timespec filetime2 = get_mtime(file2);
6153 int diff = filetime1.tv_sec - filetime2.tv_sec;
6154 if (diff == 0) {
6155 return filetime1.tv_nsec - filetime2.tv_nsec;
6156 }
6157 return diff;
6158 }
6159
6160 bool os::supports_map_sync() {
6161 return true;
6162 }
6163
6164 /////////////// Unit tests ///////////////
6165
6166 #ifndef PRODUCT
6167
6168 class TestReserveMemorySpecial : AllStatic {
6169 public:
6170 static void small_page_write(void* addr, size_t size) {
6171 size_t page_size = os::vm_page_size();
6172
6173 char* end = (char*)addr + size;
6174 for (char* p = (char*)addr; p < end; p += page_size) {
6175 *p = 1;
6176 }
6177 }
6178
6179 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) {
6180 if (!UseHugeTLBFS) {
6181 return;
6182 }
6183
6184 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false);
6185
6186 if (addr != NULL) {
6187 small_page_write(addr, size);
6188
6189 os::Linux::release_memory_special_huge_tlbfs(addr, size);
6190 }
6191 }
6192
6193 static void test_reserve_memory_special_huge_tlbfs_only() {
6194 if (!UseHugeTLBFS) {
6195 return;
6196 }
6197
6198 size_t lp = os::large_page_size();
6199
6200 for (size_t size = lp; size <= lp * 10; size += lp) {
6201 test_reserve_memory_special_huge_tlbfs_only(size);
6202 }
6203 }
6204
6205 static void test_reserve_memory_special_huge_tlbfs_mixed() {
6206 size_t lp = os::large_page_size();
6207 size_t ag = os::vm_allocation_granularity();
6208
6209 // sizes to test
6210 const size_t sizes[] = {
6211 lp, lp + ag, lp + lp / 2, lp * 2,
6212 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2,
6213 lp * 10, lp * 10 + lp / 2
6214 };
6215 const int num_sizes = sizeof(sizes) / sizeof(size_t);
6216
6217 // For each size/alignment combination, we test three scenarios:
6218 // 1) with req_addr == NULL
6219 // 2) with a non-null req_addr at which we expect to successfully allocate
6220 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we
6221 // expect the allocation to either fail or to ignore req_addr
6222
6223 // Pre-allocate two areas; they shall be as large as the largest allocation
6224 // and aligned to the largest alignment we will be testing.
6225 const size_t mapping_size = sizes[num_sizes - 1] * 2;
6226 char* const mapping1 = (char*) ::mmap(NULL, mapping_size,
6227 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6228 -1, 0);
6229 assert(mapping1 != MAP_FAILED, "should work");
6230
6231 char* const mapping2 = (char*) ::mmap(NULL, mapping_size,
6232 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
6233 -1, 0);
6234 assert(mapping2 != MAP_FAILED, "should work");
6235
6236 // Unmap the first mapping, but leave the second mapping intact: the first
6237 // mapping will serve as a value for a "good" req_addr (case 2). The second
6238 // mapping, still intact, as "bad" req_addr (case 3).
6239 ::munmap(mapping1, mapping_size);
6240
6241 // Case 1
6242 for (int i = 0; i < num_sizes; i++) {
6243 const size_t size = sizes[i];
6244 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6245 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false);
6246 if (p != NULL) {
6247 assert(is_aligned(p, alignment), "must be");
6248 small_page_write(p, size);
6249 os::Linux::release_memory_special_huge_tlbfs(p, size);
6250 }
6251 }
6252 }
6253
6254 // Case 2
6255 for (int i = 0; i < num_sizes; i++) {
6256 const size_t size = sizes[i];
6257 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6258 char* const req_addr = align_up(mapping1, alignment);
6259 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6260 if (p != NULL) {
6261 assert(p == req_addr, "must be");
6262 small_page_write(p, size);
6263 os::Linux::release_memory_special_huge_tlbfs(p, size);
6264 }
6265 }
6266 }
6267
6268 // Case 3
6269 for (int i = 0; i < num_sizes; i++) {
6270 const size_t size = sizes[i];
6271 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6272 char* const req_addr = align_up(mapping2, alignment);
6273 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
6274 // as the area around req_addr contains already existing mappings, the API should always
6275 // return NULL (as per contract, it cannot return another address)
6276 assert(p == NULL, "must be");
6277 }
6278 }
6279
6280 ::munmap(mapping2, mapping_size);
6281
6282 }
6283
6284 static void test_reserve_memory_special_huge_tlbfs() {
6285 if (!UseHugeTLBFS) {
6286 return;
6287 }
6288
6289 test_reserve_memory_special_huge_tlbfs_only();
6290 test_reserve_memory_special_huge_tlbfs_mixed();
6291 }
6292
6293 static void test_reserve_memory_special_shm(size_t size, size_t alignment) {
6294 if (!UseSHM) {
6295 return;
6296 }
6297
6298 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false);
6299
6300 if (addr != NULL) {
6301 assert(is_aligned(addr, alignment), "Check");
6302 assert(is_aligned(addr, os::large_page_size()), "Check");
6303
6304 small_page_write(addr, size);
6305
6306 os::Linux::release_memory_special_shm(addr, size);
6307 }
6308 }
6309
6310 static void test_reserve_memory_special_shm() {
6311 size_t lp = os::large_page_size();
6312 size_t ag = os::vm_allocation_granularity();
6313
6314 for (size_t size = ag; size < lp * 3; size += ag) {
6315 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
6316 test_reserve_memory_special_shm(size, alignment);
6317 }
6318 }
6319 }
6320
6321 static void test() {
6322 test_reserve_memory_special_huge_tlbfs();
6323 test_reserve_memory_special_shm();
6324 }
6325 };
6326
6327 void TestReserveMemorySpecial_test() {
6328 TestReserveMemorySpecial::test();
6329 }
6330
6331 #endif