1 /*
2 * Copyright (c) 1999, 2015, 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 #include "utilities/globalDefinitions.hpp"
26 #include "prims/jvm.h"
27 #include "semaphore_posix.hpp"
28 #include "runtime/frame.inline.hpp"
29 #include "runtime/interfaceSupport.hpp"
30 #include "runtime/os.hpp"
31 #include "utilities/vmError.hpp"
32
33 #include <signal.h>
34 #include <unistd.h>
35 #include <sys/resource.h>
36 #include <sys/utsname.h>
37 #include <pthread.h>
38 #include <semaphore.h>
39 #include <signal.h>
40
41 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
42
43 // Todo: provide a os::get_max_process_id() or similar. Number of processes
44 // may have been configured, can be read more accurately from proc fs etc.
45 #ifndef MAX_PID
46 #define MAX_PID INT_MAX
47 #endif
48 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
49
50 // Check core dump limit and report possible place where core can be found
51 void os::check_dump_limit(char* buffer, size_t bufferSize) {
52 int n;
53 struct rlimit rlim;
54 bool success;
55
56 char core_path[PATH_MAX];
57 n = get_core_path(core_path, PATH_MAX);
58
59 if (n <= 0) {
60 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
61 success = true;
62 #ifdef LINUX
63 } else if (core_path[0] == '"') { // redirect to user process
64 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
65 success = true;
66 #endif
67 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
68 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
69 success = true;
70 } else {
71 switch(rlim.rlim_cur) {
72 case RLIM_INFINITY:
73 jio_snprintf(buffer, bufferSize, "%s", core_path);
74 success = true;
75 break;
76 case 0:
77 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
78 success = false;
79 break;
80 default:
81 jio_snprintf(buffer, bufferSize, "%s (max size %lu kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", core_path, (unsigned long)(rlim.rlim_cur >> 10));
82 success = true;
83 break;
84 }
85 }
86
87 VMError::record_coredump_status(buffer, success);
88 }
89
90 int os::get_native_stack(address* stack, int frames, int toSkip) {
91 #ifdef _NMT_NOINLINE_
92 toSkip++;
93 #endif
94
95 int frame_idx = 0;
96 int num_of_frames; // number of frames captured
97 frame fr = os::current_frame();
98 while (fr.pc() && frame_idx < frames) {
99 if (toSkip > 0) {
100 toSkip --;
101 } else {
102 stack[frame_idx ++] = fr.pc();
103 }
104 if (fr.fp() == NULL || fr.cb() != NULL ||
105 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
106
107 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
108 fr = os::get_sender_for_C_frame(&fr);
109 } else {
110 break;
111 }
112 }
113 num_of_frames = frame_idx;
114 for (; frame_idx < frames; frame_idx ++) {
115 stack[frame_idx] = NULL;
116 }
117
118 return num_of_frames;
119 }
120
121
122 bool os::unsetenv(const char* name) {
123 assert(name != NULL, "Null pointer");
124 return (::unsetenv(name) == 0);
125 }
126
127 int os::get_last_error() {
128 return errno;
129 }
130
131 bool os::is_debugger_attached() {
132 // not implemented
133 return false;
134 }
135
136 void os::wait_for_keypress_at_exit(void) {
137 // don't do anything on posix platforms
138 return;
139 }
140
141 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
142 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
143 // rather than unmapping and remapping the whole chunk to get requested alignment.
144 char* os::reserve_memory_aligned(size_t size, size_t alignment) {
145 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
146 "Alignment must be a multiple of allocation granularity (page size)");
147 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
148
149 size_t extra_size = size + alignment;
150 assert(extra_size >= size, "overflow, size is too large to allow alignment");
151
152 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
153
154 if (extra_base == NULL) {
155 return NULL;
156 }
157
158 // Do manual alignment
159 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
160
161 // [ | | ]
162 // ^ extra_base
163 // ^ extra_base + begin_offset == aligned_base
164 // extra_base + begin_offset + size ^
165 // extra_base + extra_size ^
166 // |<>| == begin_offset
167 // end_offset == |<>|
168 size_t begin_offset = aligned_base - extra_base;
169 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
170
171 if (begin_offset > 0) {
172 os::release_memory(extra_base, begin_offset);
173 }
174
175 if (end_offset > 0) {
176 os::release_memory(extra_base + begin_offset + size, end_offset);
177 }
178
179 return aligned_base;
180 }
181
182 void os::Posix::print_load_average(outputStream* st) {
183 st->print("load average:");
184 double loadavg[3];
185 os::loadavg(loadavg, 3);
186 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
187 st->cr();
188 }
189
190 void os::Posix::print_rlimit_info(outputStream* st) {
191 st->print("rlimit:");
192 struct rlimit rlim;
193
194 st->print(" STACK ");
195 getrlimit(RLIMIT_STACK, &rlim);
196 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
197 else st->print("%uk", rlim.rlim_cur >> 10);
198
199 st->print(", CORE ");
200 getrlimit(RLIMIT_CORE, &rlim);
201 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
202 else st->print("%uk", rlim.rlim_cur >> 10);
203
204 // Isn't there on solaris
205 #if !defined(TARGET_OS_FAMILY_solaris) && !defined(TARGET_OS_FAMILY_aix)
206 st->print(", NPROC ");
207 getrlimit(RLIMIT_NPROC, &rlim);
208 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
209 else st->print("%d", rlim.rlim_cur);
210 #endif
211
212 st->print(", NOFILE ");
213 getrlimit(RLIMIT_NOFILE, &rlim);
214 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
215 else st->print("%d", rlim.rlim_cur);
216
217 st->print(", AS ");
218 getrlimit(RLIMIT_AS, &rlim);
219 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
220 else st->print("%uk", rlim.rlim_cur >> 10);
221 st->cr();
222 }
223
224 void os::Posix::print_uname_info(outputStream* st) {
225 // kernel
226 st->print("uname:");
227 struct utsname name;
228 uname(&name);
229 st->print("%s ", name.sysname);
230 #ifdef ASSERT
231 st->print("%s ", name.nodename);
232 #endif
233 st->print("%s ", name.release);
234 st->print("%s ", name.version);
235 st->print("%s", name.machine);
236 st->cr();
237 }
238
239 bool os::has_allocatable_memory_limit(julong* limit) {
240 struct rlimit rlim;
241 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
242 // if there was an error when calling getrlimit, assume that there is no limitation
243 // on virtual memory.
244 bool result;
245 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
246 result = false;
247 } else {
248 *limit = (julong)rlim.rlim_cur;
249 result = true;
250 }
251 #ifdef _LP64
252 return result;
253 #else
254 // arbitrary virtual space limit for 32 bit Unices found by testing. If
255 // getrlimit above returned a limit, bound it with this limit. Otherwise
256 // directly use it.
257 const julong max_virtual_limit = (julong)3800*M;
258 if (result) {
259 *limit = MIN2(*limit, max_virtual_limit);
260 } else {
261 *limit = max_virtual_limit;
262 }
263
264 // bound by actually allocatable memory. The algorithm uses two bounds, an
265 // upper and a lower limit. The upper limit is the current highest amount of
266 // memory that could not be allocated, the lower limit is the current highest
267 // amount of memory that could be allocated.
268 // The algorithm iteratively refines the result by halving the difference
269 // between these limits, updating either the upper limit (if that value could
270 // not be allocated) or the lower limit (if the that value could be allocated)
271 // until the difference between these limits is "small".
272
273 // the minimum amount of memory we care about allocating.
274 const julong min_allocation_size = M;
275
276 julong upper_limit = *limit;
277
278 // first check a few trivial cases
279 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
280 *limit = upper_limit;
281 } else if (!is_allocatable(min_allocation_size)) {
282 // we found that not even min_allocation_size is allocatable. Return it
283 // anyway. There is no point to search for a better value any more.
284 *limit = min_allocation_size;
285 } else {
286 // perform the binary search.
287 julong lower_limit = min_allocation_size;
288 while ((upper_limit - lower_limit) > min_allocation_size) {
289 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
290 temp_limit = align_size_down_(temp_limit, min_allocation_size);
291 if (is_allocatable(temp_limit)) {
292 lower_limit = temp_limit;
293 } else {
294 upper_limit = temp_limit;
295 }
296 }
297 *limit = lower_limit;
298 }
299 return true;
300 #endif
301 }
302
303 const char* os::get_current_directory(char *buf, size_t buflen) {
304 return getcwd(buf, buflen);
305 }
306
307 FILE* os::open(int fd, const char* mode) {
308 return ::fdopen(fd, mode);
309 }
310
311 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
312 // which is used to find statically linked in agents.
313 // Parameters:
314 // sym_name: Symbol in library we are looking for
315 // lib_name: Name of library to look in, NULL for shared libs.
316 // is_absolute_path == true if lib_name is absolute path to agent
317 // such as "/a/b/libL.so"
318 // == false if only the base name of the library is passed in
319 // such as "L"
320 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
321 bool is_absolute_path) {
322 char *agent_entry_name;
323 size_t len;
324 size_t name_len;
325 size_t prefix_len = strlen(JNI_LIB_PREFIX);
326 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
327 const char *start;
328
329 if (lib_name != NULL) {
330 len = name_len = strlen(lib_name);
331 if (is_absolute_path) {
332 // Need to strip path, prefix and suffix
333 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
334 lib_name = ++start;
335 }
336 if (len <= (prefix_len + suffix_len)) {
337 return NULL;
338 }
339 lib_name += prefix_len;
340 name_len = strlen(lib_name) - suffix_len;
341 }
342 }
343 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
344 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
345 if (agent_entry_name == NULL) {
346 return NULL;
347 }
348 strcpy(agent_entry_name, sym_name);
349 if (lib_name != NULL) {
350 strcat(agent_entry_name, "_");
351 strncat(agent_entry_name, lib_name, name_len);
352 }
353 return agent_entry_name;
354 }
355
356 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
357 assert(thread == Thread::current(), "thread consistency check");
358
359 ParkEvent * const slp = thread->_SleepEvent ;
360 slp->reset() ;
361 OrderAccess::fence() ;
362
363 if (interruptible) {
364 jlong prevtime = javaTimeNanos();
365
366 for (;;) {
367 if (os::is_interrupted(thread, true)) {
368 return OS_INTRPT;
369 }
370
371 jlong newtime = javaTimeNanos();
372
373 if (newtime - prevtime < 0) {
374 // time moving backwards, should only happen if no monotonic clock
375 // not a guarantee() because JVM should not abort on kernel/glibc bugs
376 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
377 } else {
378 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
379 }
380
381 if (millis <= 0) {
382 return OS_OK;
383 }
384
385 prevtime = newtime;
386
387 {
388 assert(thread->is_Java_thread(), "sanity check");
389 JavaThread *jt = (JavaThread *) thread;
390 ThreadBlockInVM tbivm(jt);
391 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
392
393 jt->set_suspend_equivalent();
394 // cleared by handle_special_suspend_equivalent_condition() or
395 // java_suspend_self() via check_and_wait_while_suspended()
396
397 slp->park(millis);
398
399 // were we externally suspended while we were waiting?
400 jt->check_and_wait_while_suspended();
401 }
402 }
403 } else {
404 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
405 jlong prevtime = javaTimeNanos();
406
407 for (;;) {
408 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
409 // the 1st iteration ...
410 jlong newtime = javaTimeNanos();
411
412 if (newtime - prevtime < 0) {
413 // time moving backwards, should only happen if no monotonic clock
414 // not a guarantee() because JVM should not abort on kernel/glibc bugs
415 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
416 } else {
417 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
418 }
419
420 if (millis <= 0) break ;
421
422 prevtime = newtime;
423 slp->park(millis);
424 }
425 return OS_OK ;
426 }
427 }
428
429 ////////////////////////////////////////////////////////////////////////////////
430 // interrupt support
431
432 void os::interrupt(Thread* thread) {
433 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
434 "possibility of dangling Thread pointer");
435
436 OSThread* osthread = thread->osthread();
437
438 if (!osthread->interrupted()) {
439 osthread->set_interrupted(true);
440 // More than one thread can get here with the same value of osthread,
441 // resulting in multiple notifications. We do, however, want the store
442 // to interrupted() to be visible to other threads before we execute unpark().
443 OrderAccess::fence();
444 ParkEvent * const slp = thread->_SleepEvent ;
445 if (slp != NULL) slp->unpark() ;
446 }
447
448 // For JSR166. Unpark even if interrupt status already was set
449 if (thread->is_Java_thread())
450 ((JavaThread*)thread)->parker()->unpark();
451
452 ParkEvent * ev = thread->_ParkEvent ;
453 if (ev != NULL) ev->unpark() ;
454
455 }
456
457 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
458 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
459 "possibility of dangling Thread pointer");
460
461 OSThread* osthread = thread->osthread();
462
463 bool interrupted = osthread->interrupted();
464
465 // NOTE that since there is no "lock" around the interrupt and
466 // is_interrupted operations, there is the possibility that the
467 // interrupted flag (in osThread) will be "false" but that the
468 // low-level events will be in the signaled state. This is
469 // intentional. The effect of this is that Object.wait() and
470 // LockSupport.park() will appear to have a spurious wakeup, which
471 // is allowed and not harmful, and the possibility is so rare that
472 // it is not worth the added complexity to add yet another lock.
473 // For the sleep event an explicit reset is performed on entry
474 // to os::sleep, so there is no early return. It has also been
475 // recommended not to put the interrupted flag into the "event"
476 // structure because it hides the issue.
477 if (interrupted && clear_interrupted) {
478 osthread->set_interrupted(false);
479 // consider thread->_SleepEvent->reset() ... optional optimization
480 }
481
482 return interrupted;
483 }
484
485 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
486 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
487
488 static const struct {
489 int sig; const char* name;
490 }
491 info[] =
492 {
493 { SIGABRT, "SIGABRT" },
494 #ifdef SIGAIO
495 { SIGAIO, "SIGAIO" },
496 #endif
497 { SIGALRM, "SIGALRM" },
498 #ifdef SIGALRM1
499 { SIGALRM1, "SIGALRM1" },
500 #endif
501 { SIGBUS, "SIGBUS" },
502 #ifdef SIGCANCEL
503 { SIGCANCEL, "SIGCANCEL" },
504 #endif
505 { SIGCHLD, "SIGCHLD" },
506 #ifdef SIGCLD
507 { SIGCLD, "SIGCLD" },
508 #endif
509 { SIGCONT, "SIGCONT" },
510 #ifdef SIGCPUFAIL
511 { SIGCPUFAIL, "SIGCPUFAIL" },
512 #endif
513 #ifdef SIGDANGER
514 { SIGDANGER, "SIGDANGER" },
515 #endif
516 #ifdef SIGDIL
517 { SIGDIL, "SIGDIL" },
518 #endif
519 #ifdef SIGEMT
520 { SIGEMT, "SIGEMT" },
521 #endif
522 { SIGFPE, "SIGFPE" },
523 #ifdef SIGFREEZE
524 { SIGFREEZE, "SIGFREEZE" },
525 #endif
526 #ifdef SIGGFAULT
527 { SIGGFAULT, "SIGGFAULT" },
528 #endif
529 #ifdef SIGGRANT
530 { SIGGRANT, "SIGGRANT" },
531 #endif
532 { SIGHUP, "SIGHUP" },
533 { SIGILL, "SIGILL" },
534 { SIGINT, "SIGINT" },
535 #ifdef SIGIO
536 { SIGIO, "SIGIO" },
537 #endif
538 #ifdef SIGIOINT
539 { SIGIOINT, "SIGIOINT" },
540 #endif
541 #ifdef SIGIOT
542 // SIGIOT is there for BSD compatibility, but on most Unices just a
543 // synonym for SIGABRT. The result should be "SIGABRT", not
544 // "SIGIOT".
545 #if (SIGIOT != SIGABRT )
546 { SIGIOT, "SIGIOT" },
547 #endif
548 #endif
549 #ifdef SIGKAP
550 { SIGKAP, "SIGKAP" },
551 #endif
552 { SIGKILL, "SIGKILL" },
553 #ifdef SIGLOST
554 { SIGLOST, "SIGLOST" },
555 #endif
556 #ifdef SIGLWP
557 { SIGLWP, "SIGLWP" },
558 #endif
559 #ifdef SIGLWPTIMER
560 { SIGLWPTIMER, "SIGLWPTIMER" },
561 #endif
562 #ifdef SIGMIGRATE
563 { SIGMIGRATE, "SIGMIGRATE" },
564 #endif
565 #ifdef SIGMSG
566 { SIGMSG, "SIGMSG" },
567 #endif
568 { SIGPIPE, "SIGPIPE" },
569 #ifdef SIGPOLL
570 { SIGPOLL, "SIGPOLL" },
571 #endif
572 #ifdef SIGPRE
573 { SIGPRE, "SIGPRE" },
574 #endif
575 { SIGPROF, "SIGPROF" },
576 #ifdef SIGPTY
577 { SIGPTY, "SIGPTY" },
578 #endif
579 #ifdef SIGPWR
580 { SIGPWR, "SIGPWR" },
581 #endif
582 { SIGQUIT, "SIGQUIT" },
583 #ifdef SIGRECONFIG
584 { SIGRECONFIG, "SIGRECONFIG" },
585 #endif
586 #ifdef SIGRECOVERY
587 { SIGRECOVERY, "SIGRECOVERY" },
588 #endif
589 #ifdef SIGRESERVE
590 { SIGRESERVE, "SIGRESERVE" },
591 #endif
592 #ifdef SIGRETRACT
593 { SIGRETRACT, "SIGRETRACT" },
594 #endif
595 #ifdef SIGSAK
596 { SIGSAK, "SIGSAK" },
597 #endif
598 { SIGSEGV, "SIGSEGV" },
599 #ifdef SIGSOUND
600 { SIGSOUND, "SIGSOUND" },
601 #endif
602 { SIGSTOP, "SIGSTOP" },
603 { SIGSYS, "SIGSYS" },
604 #ifdef SIGSYSERROR
605 { SIGSYSERROR, "SIGSYSERROR" },
606 #endif
607 #ifdef SIGTALRM
608 { SIGTALRM, "SIGTALRM" },
609 #endif
610 { SIGTERM, "SIGTERM" },
611 #ifdef SIGTHAW
612 { SIGTHAW, "SIGTHAW" },
613 #endif
614 { SIGTRAP, "SIGTRAP" },
615 #ifdef SIGTSTP
616 { SIGTSTP, "SIGTSTP" },
617 #endif
618 { SIGTTIN, "SIGTTIN" },
619 { SIGTTOU, "SIGTTOU" },
620 #ifdef SIGURG
621 { SIGURG, "SIGURG" },
622 #endif
623 { SIGUSR1, "SIGUSR1" },
624 { SIGUSR2, "SIGUSR2" },
625 #ifdef SIGVIRT
626 { SIGVIRT, "SIGVIRT" },
627 #endif
628 { SIGVTALRM, "SIGVTALRM" },
629 #ifdef SIGWAITING
630 { SIGWAITING, "SIGWAITING" },
631 #endif
632 #ifdef SIGWINCH
633 { SIGWINCH, "SIGWINCH" },
634 #endif
635 #ifdef SIGWINDOW
636 { SIGWINDOW, "SIGWINDOW" },
637 #endif
638 { SIGXCPU, "SIGXCPU" },
639 { SIGXFSZ, "SIGXFSZ" },
640 #ifdef SIGXRES
641 { SIGXRES, "SIGXRES" },
642 #endif
643 { -1, NULL }
644 };
645
646 const char* ret = NULL;
647
648 #ifdef SIGRTMIN
649 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
650 if (sig == SIGRTMIN) {
651 ret = "SIGRTMIN";
652 } else if (sig == SIGRTMAX) {
653 ret = "SIGRTMAX";
654 } else {
655 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
656 return out;
657 }
658 }
659 #endif
660
661 if (sig > 0) {
662 for (int idx = 0; info[idx].sig != -1; idx ++) {
663 if (info[idx].sig == sig) {
664 ret = info[idx].name;
665 break;
666 }
667 }
668 }
669
670 if (!ret) {
671 if (!is_valid_signal(sig)) {
672 ret = "INVALID";
673 } else {
674 ret = "UNKNOWN";
675 }
676 }
677
678 if (out && outlen > 0) {
679 strncpy(out, ret, outlen);
680 out[outlen - 1] = '\0';
681 }
682 return out;
683 }
684
685 // Returns true if signal number is valid.
686 bool os::Posix::is_valid_signal(int sig) {
687 // MacOS not really POSIX compliant: sigaddset does not return
688 // an error for invalid signal numbers. However, MacOS does not
689 // support real time signals and simply seems to have just 33
690 // signals with no holes in the signal range.
691 #ifdef __APPLE__
692 return sig >= 1 && sig < NSIG;
693 #else
694 // Use sigaddset to check for signal validity.
695 sigset_t set;
696 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
697 return false;
698 }
699 return true;
700 #endif
701 }
702
703 #define NUM_IMPORTANT_SIGS 32
704 // Returns one-line short description of a signal set in a user provided buffer.
705 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
706 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
707 // Note: for shortness, just print out the first 32. That should
708 // cover most of the useful ones, apart from realtime signals.
709 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
710 const int rc = sigismember(set, sig);
711 if (rc == -1 && errno == EINVAL) {
712 buffer[sig-1] = '?';
713 } else {
714 buffer[sig-1] = rc == 0 ? '0' : '1';
715 }
716 }
717 buffer[NUM_IMPORTANT_SIGS] = 0;
718 return buffer;
719 }
720
721 // Prints one-line description of a signal set.
722 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
723 char buf[NUM_IMPORTANT_SIGS + 1];
724 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
725 st->print("%s", buf);
726 }
727
728 // Writes one-line description of a combination of sigaction.sa_flags into a user
729 // provided buffer. Returns that buffer.
730 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
731 char* p = buffer;
732 size_t remaining = size;
733 bool first = true;
734 int idx = 0;
735
736 assert(buffer, "invalid argument");
737
738 if (size == 0) {
739 return buffer;
740 }
741
742 strncpy(buffer, "none", size);
743
744 const struct {
745 int i;
746 const char* s;
747 } flaginfo [] = {
748 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
749 { SA_ONSTACK, "SA_ONSTACK" },
750 { SA_RESETHAND, "SA_RESETHAND" },
751 { SA_RESTART, "SA_RESTART" },
752 { SA_SIGINFO, "SA_SIGINFO" },
753 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
754 { SA_NODEFER, "SA_NODEFER" },
755 #ifdef AIX
756 { SA_ONSTACK, "SA_ONSTACK" },
757 { SA_OLDSTYLE, "SA_OLDSTYLE" },
758 #endif
759 { 0, NULL }
760 };
761
762 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
763 if (flags & flaginfo[idx].i) {
764 if (first) {
765 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
766 first = false;
767 } else {
768 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
769 }
770 const size_t len = strlen(p);
771 p += len;
772 remaining -= len;
773 }
774 }
775
776 buffer[size - 1] = '\0';
777
778 return buffer;
779 }
780
781 // Prints one-line description of a combination of sigaction.sa_flags.
782 void os::Posix::print_sa_flags(outputStream* st, int flags) {
783 char buffer[0x100];
784 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
785 st->print("%s", buffer);
786 }
787
788 // Helper function for os::Posix::print_siginfo_...():
789 // return a textual description for signal code.
790 struct enum_sigcode_desc_t {
791 const char* s_name;
792 const char* s_desc;
793 };
794
795 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
796
797 const struct {
798 int sig; int code; const char* s_code; const char* s_desc;
799 } t1 [] = {
800 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
801 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
802 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
803 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
804 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
805 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
806 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
807 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
808 #if defined(IA64) && defined(LINUX)
809 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
810 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
811 #endif
812 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
813 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
814 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
815 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
816 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
817 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
818 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
819 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
820 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
821 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
822 #ifdef AIX
823 // no explanation found what keyerr would be
824 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
825 #endif
826 #if defined(IA64) && !defined(AIX)
827 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
828 #endif
829 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
830 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
831 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
832 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
833 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
834 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
835 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
836 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
837 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
838 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
839 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
840 #ifdef SIGPOLL
841 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
842 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
843 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
844 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
845 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
846 #endif
847 { -1, -1, NULL, NULL }
848 };
849
850 // Codes valid in any signal context.
851 const struct {
852 int code; const char* s_code; const char* s_desc;
853 } t2 [] = {
854 { SI_USER, "SI_USER", "Signal sent by kill()." },
855 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
856 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
857 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
858 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
859 // Linux specific
860 #ifdef SI_TKILL
861 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
862 #endif
863 #ifdef SI_DETHREAD
864 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
865 #endif
866 #ifdef SI_KERNEL
867 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
868 #endif
869 #ifdef SI_SIGIO
870 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
871 #endif
872
873 #ifdef AIX
874 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
875 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
876 #endif
877
878 #ifdef __sun
879 { SI_NOINFO, "SI_NOINFO", "No signal information" },
880 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
881 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
882 #endif
883
884 { -1, NULL, NULL }
885 };
886
887 const char* s_code = NULL;
888 const char* s_desc = NULL;
889
890 for (int i = 0; t1[i].sig != -1; i ++) {
891 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
892 s_code = t1[i].s_code;
893 s_desc = t1[i].s_desc;
894 break;
895 }
896 }
897
898 if (s_code == NULL) {
899 for (int i = 0; t2[i].s_code != NULL; i ++) {
900 if (t2[i].code == si->si_code) {
901 s_code = t2[i].s_code;
902 s_desc = t2[i].s_desc;
903 }
904 }
905 }
906
907 if (s_code == NULL) {
908 out->s_name = "unknown";
909 out->s_desc = "unknown";
910 return false;
911 }
912
913 out->s_name = s_code;
914 out->s_desc = s_desc;
915
916 return true;
917 }
918
919 // A POSIX conform, platform-independend siginfo print routine.
920 // Short print out on one line.
921 void os::Posix::print_siginfo_brief(outputStream* os, const siginfo_t* si) {
922 char buf[20];
923 os->print("siginfo: ");
924
925 if (!si) {
926 os->print("<null>");
927 return;
928 }
929
930 // See print_siginfo_full() for details.
931 const int sig = si->si_signo;
932
933 os->print("si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
934
935 enum_sigcode_desc_t ed;
936 if (get_signal_code_description(si, &ed)) {
937 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
938 } else {
939 os->print(", si_code: %d (unknown)", si->si_code);
940 }
941
942 if (si->si_errno) {
943 os->print(", si_errno: %d", si->si_errno);
944 }
945
946 const int me = (int) ::getpid();
947 const int pid = (int) si->si_pid;
948
949 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
950 if (IS_VALID_PID(pid) && pid != me) {
951 os->print(", sent from pid: %d (uid: %d)", pid, (int) si->si_uid);
952 }
953 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
954 sig == SIGTRAP || sig == SIGFPE) {
955 os->print(", si_addr: " PTR_FORMAT, si->si_addr);
956 #ifdef SIGPOLL
957 } else if (sig == SIGPOLL) {
958 os->print(", si_band: " PTR64_FORMAT, (uint64_t)si->si_band);
959 #endif
960 } else if (sig == SIGCHLD) {
961 os->print_cr(", si_pid: %d, si_uid: %d, si_status: %d", (int) si->si_pid, si->si_uid, si->si_status);
962 }
963 }
964
965 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
966 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
967 }
968
969 /*
970 * See the caveats for this class in os_posix.hpp
971 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
972 * method and returns false. If none of the signals are raised, returns true.
973 * The callback is supposed to provide the method that should be protected.
974 */
975 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
976 sigset_t saved_sig_mask;
977
978 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
979 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
980 "crash_protection already set?");
981
982 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
983 // since on at least some systems (OS X) siglongjmp will restore the mask
984 // for the process, not the thread
985 pthread_sigmask(0, NULL, &saved_sig_mask);
986 if (sigsetjmp(_jmpbuf, 0) == 0) {
987 // make sure we can see in the signal handler that we have crash protection
988 // installed
989 WatcherThread::watcher_thread()->set_crash_protection(this);
990 cb.call();
991 // and clear the crash protection
992 WatcherThread::watcher_thread()->set_crash_protection(NULL);
993 return true;
994 }
995 // this happens when we siglongjmp() back
996 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
997 WatcherThread::watcher_thread()->set_crash_protection(NULL);
998 return false;
999 }
1000
1001 void os::WatcherThreadCrashProtection::restore() {
1002 assert(WatcherThread::watcher_thread()->has_crash_protection(),
1003 "must have crash protection");
1004
1005 siglongjmp(_jmpbuf, 1);
1006 }
1007
1008 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1009 Thread* thread) {
1010
1011 if (thread != NULL &&
1012 thread->is_Watcher_thread() &&
1013 WatcherThread::watcher_thread()->has_crash_protection()) {
1014
1015 if (sig == SIGSEGV || sig == SIGBUS) {
1016 WatcherThread::watcher_thread()->crash_protection()->restore();
1017 }
1018 }
1019 }
1020
1021 #define check_with_errno(check_type, cond, msg) \
1022 do { \
1023 int err = errno; \
1024 check_type(cond, err_msg("%s; error='%s' (errno=%d)", msg, strerror(err), err)); \
1025 } while (false)
1026
1027 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
1028 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
1029
1030 // POSIX unamed semaphores are not supported on OS X.
1031 #ifndef __APPLE__
1032
1033 PosixSemaphore::PosixSemaphore(uint value) {
1034 int ret = sem_init(&_semaphore, 0, value);
1035
1036 guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1037 }
1038
1039 PosixSemaphore::~PosixSemaphore() {
1040 sem_destroy(&_semaphore);
1041 }
1042
1043 void PosixSemaphore::signal(uint count) {
1044 for (uint i = 0; i < count; i++) {
1045 int ret = sem_post(&_semaphore);
1046
1047 assert_with_errno(ret == 0, "sem_post failed");
1048 }
1049 }
1050
1051 void PosixSemaphore::wait() {
1052 int ret;
1053
1054 do {
1055 ret = sem_wait(&_semaphore);
1056 } while (ret != 0 && errno == EINTR);
1057
1058 assert_with_errno(ret == 0, "sem_wait failed");
1059 }
1060
1061 bool PosixSemaphore::trywait() {
1062 int ret;
1063
1064 do {
1065 ret = sem_trywait(&_semaphore);
1066 } while (ret != 0 && errno == EINTR);
1067
1068 assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1069
1070 return ret == 0;
1071 }
1072
1073 bool PosixSemaphore::timedwait(const struct timespec ts) {
1074 while (true) {
1075 int result = sem_timedwait(&_semaphore, &ts);
1076 if (result == 0) {
1077 return true;
1078 } else if (errno == EINTR) {
1079 continue;
1080 } else if (errno == ETIMEDOUT) {
1081 return false;
1082 } else {
1083 assert_with_errno(false, "timedwait failed");
1084 return false;
1085 }
1086 }
1087 }
1088
1089 #endif // __APPLE__