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 // Todo: provide a os::get_max_process_id() or similar. Number of processes
42 // may have been configured, can be read more accurately from proc fs etc.
43 #ifndef MAX_PID
44 #define MAX_PID INT_MAX
45 #endif
46 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
47
48 // Check core dump limit and report possible place where core can be found
49 void os::check_dump_limit(char* buffer, size_t bufferSize) {
50 int n;
51 struct rlimit rlim;
52 bool success;
53
54 char core_path[PATH_MAX];
55 n = get_core_path(core_path, PATH_MAX);
56
57 if (n <= 0) {
58 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
59 success = true;
60 #ifdef LINUX
61 } else if (core_path[0] == '"') { // redirect to user process
62 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
63 success = true;
64 #endif
65 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
66 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
67 success = true;
68 } else {
69 switch(rlim.rlim_cur) {
70 case RLIM_INFINITY:
71 jio_snprintf(buffer, bufferSize, "%s", core_path);
72 success = true;
73 break;
74 case 0:
75 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
76 success = false;
77 break;
78 default:
79 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));
80 success = true;
81 break;
82 }
83 }
84
85 VMError::record_coredump_status(buffer, success);
86 }
87
88 int os::get_native_stack(address* stack, int frames, int toSkip) {
89 #ifdef _NMT_NOINLINE_
90 toSkip++;
91 #endif
92
93 int frame_idx = 0;
94 int num_of_frames; // number of frames captured
95 frame fr = os::current_frame();
96 while (fr.pc() && frame_idx < frames) {
97 if (toSkip > 0) {
98 toSkip --;
99 } else {
100 stack[frame_idx ++] = fr.pc();
101 }
102 if (fr.fp() == NULL || fr.cb() != NULL ||
103 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
104
105 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
106 fr = os::get_sender_for_C_frame(&fr);
107 } else {
108 break;
109 }
110 }
111 num_of_frames = frame_idx;
112 for (; frame_idx < frames; frame_idx ++) {
113 stack[frame_idx] = NULL;
114 }
115
116 return num_of_frames;
117 }
118
119
120 bool os::unsetenv(const char* name) {
121 assert(name != NULL, "Null pointer");
122 return (::unsetenv(name) == 0);
123 }
124
125 int os::get_last_error() {
126 return errno;
127 }
128
129 bool os::is_debugger_attached() {
130 // not implemented
131 return false;
132 }
133
134 void os::wait_for_keypress_at_exit(void) {
135 // don't do anything on posix platforms
136 return;
137 }
138
139 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
140 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
141 // rather than unmapping and remapping the whole chunk to get requested alignment.
142 char* os::reserve_memory_aligned(size_t size, size_t alignment) {
143 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
144 "Alignment must be a multiple of allocation granularity (page size)");
145 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
146
147 size_t extra_size = size + alignment;
148 assert(extra_size >= size, "overflow, size is too large to allow alignment");
149
150 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
151
152 if (extra_base == NULL) {
153 return NULL;
154 }
155
156 // Do manual alignment
157 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
158
159 // [ | | ]
160 // ^ extra_base
161 // ^ extra_base + begin_offset == aligned_base
162 // extra_base + begin_offset + size ^
163 // extra_base + extra_size ^
164 // |<>| == begin_offset
165 // end_offset == |<>|
166 size_t begin_offset = aligned_base - extra_base;
167 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
168
169 if (begin_offset > 0) {
170 os::release_memory(extra_base, begin_offset);
171 }
172
173 if (end_offset > 0) {
174 os::release_memory(extra_base + begin_offset + size, end_offset);
175 }
176
177 return aligned_base;
178 }
179
180 void os::Posix::print_load_average(outputStream* st) {
181 st->print("load average:");
182 double loadavg[3];
183 os::loadavg(loadavg, 3);
184 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
185 st->cr();
186 }
187
188 void os::Posix::print_rlimit_info(outputStream* st) {
189 st->print("rlimit:");
190 struct rlimit rlim;
191
192 st->print(" STACK ");
193 getrlimit(RLIMIT_STACK, &rlim);
194 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
195 else st->print("%uk", (uint)rlim.rlim_cur >> 10);
196
197 st->print(", CORE ");
198 getrlimit(RLIMIT_CORE, &rlim);
199 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
200 else st->print("%uk", (uint)rlim.rlim_cur >> 10);
201
202 // Isn't there on solaris
203 #if !defined(TARGET_OS_FAMILY_solaris) && !defined(TARGET_OS_FAMILY_aix)
204 st->print(", NPROC ");
205 getrlimit(RLIMIT_NPROC, &rlim);
206 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
207 else st->print("%d", (uint)rlim.rlim_cur);
208 #endif
209
210 st->print(", NOFILE ");
211 getrlimit(RLIMIT_NOFILE, &rlim);
212 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
213 else st->print("%d", (uint)rlim.rlim_cur);
214
215 st->print(", AS ");
216 getrlimit(RLIMIT_AS, &rlim);
217 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
218 else st->print("%uk", (uint)rlim.rlim_cur >> 10);
219 st->cr();
220 }
221
222 void os::Posix::print_uname_info(outputStream* st) {
223 // kernel
224 st->print("uname:");
225 struct utsname name;
226 uname(&name);
227 st->print("%s ", name.sysname);
228 #ifdef ASSERT
229 st->print("%s ", name.nodename);
230 #endif
231 st->print("%s ", name.release);
232 st->print("%s ", name.version);
233 st->print("%s", name.machine);
234 st->cr();
235 }
236
237 #ifndef PRODUCT
238 bool os::get_host_name(char* buf, size_t buflen) {
239 struct utsname name;
240 uname(&name);
241 jio_snprintf(buf, buflen, "%s", name.nodename);
242 return true;
243 }
244 #endif // PRODUCT
245
246 bool os::has_allocatable_memory_limit(julong* limit) {
247 struct rlimit rlim;
248 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
249 // if there was an error when calling getrlimit, assume that there is no limitation
250 // on virtual memory.
251 bool result;
252 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
253 result = false;
254 } else {
255 *limit = (julong)rlim.rlim_cur;
256 result = true;
257 }
258 #ifdef _LP64
259 return result;
260 #else
261 // arbitrary virtual space limit for 32 bit Unices found by testing. If
262 // getrlimit above returned a limit, bound it with this limit. Otherwise
263 // directly use it.
264 const julong max_virtual_limit = (julong)3800*M;
265 if (result) {
266 *limit = MIN2(*limit, max_virtual_limit);
267 } else {
268 *limit = max_virtual_limit;
269 }
270
271 // bound by actually allocatable memory. The algorithm uses two bounds, an
272 // upper and a lower limit. The upper limit is the current highest amount of
273 // memory that could not be allocated, the lower limit is the current highest
274 // amount of memory that could be allocated.
275 // The algorithm iteratively refines the result by halving the difference
276 // between these limits, updating either the upper limit (if that value could
277 // not be allocated) or the lower limit (if the that value could be allocated)
278 // until the difference between these limits is "small".
279
280 // the minimum amount of memory we care about allocating.
281 const julong min_allocation_size = M;
282
283 julong upper_limit = *limit;
284
285 // first check a few trivial cases
286 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
287 *limit = upper_limit;
288 } else if (!is_allocatable(min_allocation_size)) {
289 // we found that not even min_allocation_size is allocatable. Return it
290 // anyway. There is no point to search for a better value any more.
291 *limit = min_allocation_size;
292 } else {
293 // perform the binary search.
294 julong lower_limit = min_allocation_size;
295 while ((upper_limit - lower_limit) > min_allocation_size) {
296 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
297 temp_limit = align_size_down_(temp_limit, min_allocation_size);
298 if (is_allocatable(temp_limit)) {
299 lower_limit = temp_limit;
300 } else {
301 upper_limit = temp_limit;
302 }
303 }
304 *limit = lower_limit;
305 }
306 return true;
307 #endif
308 }
309
310 const char* os::get_current_directory(char *buf, size_t buflen) {
311 return getcwd(buf, buflen);
312 }
313
314 FILE* os::open(int fd, const char* mode) {
315 return ::fdopen(fd, mode);
316 }
317
318 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
319 // which is used to find statically linked in agents.
320 // Parameters:
321 // sym_name: Symbol in library we are looking for
322 // lib_name: Name of library to look in, NULL for shared libs.
323 // is_absolute_path == true if lib_name is absolute path to agent
324 // such as "/a/b/libL.so"
325 // == false if only the base name of the library is passed in
326 // such as "L"
327 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
328 bool is_absolute_path) {
329 char *agent_entry_name;
330 size_t len;
331 size_t name_len;
332 size_t prefix_len = strlen(JNI_LIB_PREFIX);
333 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
334 const char *start;
335
336 if (lib_name != NULL) {
337 len = name_len = strlen(lib_name);
338 if (is_absolute_path) {
339 // Need to strip path, prefix and suffix
340 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
341 lib_name = ++start;
342 }
343 if (len <= (prefix_len + suffix_len)) {
344 return NULL;
345 }
346 lib_name += prefix_len;
347 name_len = strlen(lib_name) - suffix_len;
348 }
349 }
350 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
351 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
352 if (agent_entry_name == NULL) {
353 return NULL;
354 }
355 strcpy(agent_entry_name, sym_name);
356 if (lib_name != NULL) {
357 strcat(agent_entry_name, "_");
358 strncat(agent_entry_name, lib_name, name_len);
359 }
360 return agent_entry_name;
361 }
362
363 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
364 assert(thread == Thread::current(), "thread consistency check");
365
366 ParkEvent * const slp = thread->_SleepEvent ;
367 slp->reset() ;
368 OrderAccess::fence() ;
369
370 if (interruptible) {
371 jlong prevtime = javaTimeNanos();
372
373 for (;;) {
374 if (os::is_interrupted(thread, true)) {
375 return OS_INTRPT;
376 }
377
378 jlong newtime = javaTimeNanos();
379
380 if (newtime - prevtime < 0) {
381 // time moving backwards, should only happen if no monotonic clock
382 // not a guarantee() because JVM should not abort on kernel/glibc bugs
383 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
384 } else {
385 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
386 }
387
388 if (millis <= 0) {
389 return OS_OK;
390 }
391
392 prevtime = newtime;
393
394 {
395 assert(thread->is_Java_thread(), "sanity check");
396 JavaThread *jt = (JavaThread *) thread;
397 ThreadBlockInVM tbivm(jt);
398 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
399
400 jt->set_suspend_equivalent();
401 // cleared by handle_special_suspend_equivalent_condition() or
402 // java_suspend_self() via check_and_wait_while_suspended()
403
404 slp->park(millis);
405
406 // were we externally suspended while we were waiting?
407 jt->check_and_wait_while_suspended();
408 }
409 }
410 } else {
411 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
412 jlong prevtime = javaTimeNanos();
413
414 for (;;) {
415 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
416 // the 1st iteration ...
417 jlong newtime = javaTimeNanos();
418
419 if (newtime - prevtime < 0) {
420 // time moving backwards, should only happen if no monotonic clock
421 // not a guarantee() because JVM should not abort on kernel/glibc bugs
422 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
423 } else {
424 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
425 }
426
427 if (millis <= 0) break ;
428
429 prevtime = newtime;
430 slp->park(millis);
431 }
432 return OS_OK ;
433 }
434 }
435
436 ////////////////////////////////////////////////////////////////////////////////
437 // interrupt support
438
439 void os::interrupt(Thread* thread) {
440 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
441 "possibility of dangling Thread pointer");
442
443 OSThread* osthread = thread->osthread();
444
445 if (!osthread->interrupted()) {
446 osthread->set_interrupted(true);
447 // More than one thread can get here with the same value of osthread,
448 // resulting in multiple notifications. We do, however, want the store
449 // to interrupted() to be visible to other threads before we execute unpark().
450 OrderAccess::fence();
451 ParkEvent * const slp = thread->_SleepEvent ;
452 if (slp != NULL) slp->unpark() ;
453 }
454
455 // For JSR166. Unpark even if interrupt status already was set
456 if (thread->is_Java_thread())
457 ((JavaThread*)thread)->parker()->unpark();
458
459 ParkEvent * ev = thread->_ParkEvent ;
460 if (ev != NULL) ev->unpark() ;
461
462 }
463
464 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
465 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
466 "possibility of dangling Thread pointer");
467
468 OSThread* osthread = thread->osthread();
469
470 bool interrupted = osthread->interrupted();
471
472 // NOTE that since there is no "lock" around the interrupt and
473 // is_interrupted operations, there is the possibility that the
474 // interrupted flag (in osThread) will be "false" but that the
475 // low-level events will be in the signaled state. This is
476 // intentional. The effect of this is that Object.wait() and
477 // LockSupport.park() will appear to have a spurious wakeup, which
478 // is allowed and not harmful, and the possibility is so rare that
479 // it is not worth the added complexity to add yet another lock.
480 // For the sleep event an explicit reset is performed on entry
481 // to os::sleep, so there is no early return. It has also been
482 // recommended not to put the interrupted flag into the "event"
483 // structure because it hides the issue.
484 if (interrupted && clear_interrupted) {
485 osthread->set_interrupted(false);
486 // consider thread->_SleepEvent->reset() ... optional optimization
487 }
488
489 return interrupted;
490 }
491
492 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
493 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
494
495 static const struct {
496 int sig; const char* name;
497 }
498 info[] =
499 {
500 { SIGABRT, "SIGABRT" },
501 #ifdef SIGAIO
502 { SIGAIO, "SIGAIO" },
503 #endif
504 { SIGALRM, "SIGALRM" },
505 #ifdef SIGALRM1
506 { SIGALRM1, "SIGALRM1" },
507 #endif
508 { SIGBUS, "SIGBUS" },
509 #ifdef SIGCANCEL
510 { SIGCANCEL, "SIGCANCEL" },
511 #endif
512 { SIGCHLD, "SIGCHLD" },
513 #ifdef SIGCLD
514 { SIGCLD, "SIGCLD" },
515 #endif
516 { SIGCONT, "SIGCONT" },
517 #ifdef SIGCPUFAIL
518 { SIGCPUFAIL, "SIGCPUFAIL" },
519 #endif
520 #ifdef SIGDANGER
521 { SIGDANGER, "SIGDANGER" },
522 #endif
523 #ifdef SIGDIL
524 { SIGDIL, "SIGDIL" },
525 #endif
526 #ifdef SIGEMT
527 { SIGEMT, "SIGEMT" },
528 #endif
529 { SIGFPE, "SIGFPE" },
530 #ifdef SIGFREEZE
531 { SIGFREEZE, "SIGFREEZE" },
532 #endif
533 #ifdef SIGGFAULT
534 { SIGGFAULT, "SIGGFAULT" },
535 #endif
536 #ifdef SIGGRANT
537 { SIGGRANT, "SIGGRANT" },
538 #endif
539 { SIGHUP, "SIGHUP" },
540 { SIGILL, "SIGILL" },
541 { SIGINT, "SIGINT" },
542 #ifdef SIGIO
543 { SIGIO, "SIGIO" },
544 #endif
545 #ifdef SIGIOINT
546 { SIGIOINT, "SIGIOINT" },
547 #endif
548 #ifdef SIGIOT
549 // SIGIOT is there for BSD compatibility, but on most Unices just a
550 // synonym for SIGABRT. The result should be "SIGABRT", not
551 // "SIGIOT".
552 #if (SIGIOT != SIGABRT )
553 { SIGIOT, "SIGIOT" },
554 #endif
555 #endif
556 #ifdef SIGKAP
557 { SIGKAP, "SIGKAP" },
558 #endif
559 { SIGKILL, "SIGKILL" },
560 #ifdef SIGLOST
561 { SIGLOST, "SIGLOST" },
562 #endif
563 #ifdef SIGLWP
564 { SIGLWP, "SIGLWP" },
565 #endif
566 #ifdef SIGLWPTIMER
567 { SIGLWPTIMER, "SIGLWPTIMER" },
568 #endif
569 #ifdef SIGMIGRATE
570 { SIGMIGRATE, "SIGMIGRATE" },
571 #endif
572 #ifdef SIGMSG
573 { SIGMSG, "SIGMSG" },
574 #endif
575 { SIGPIPE, "SIGPIPE" },
576 #ifdef SIGPOLL
577 { SIGPOLL, "SIGPOLL" },
578 #endif
579 #ifdef SIGPRE
580 { SIGPRE, "SIGPRE" },
581 #endif
582 { SIGPROF, "SIGPROF" },
583 #ifdef SIGPTY
584 { SIGPTY, "SIGPTY" },
585 #endif
586 #ifdef SIGPWR
587 { SIGPWR, "SIGPWR" },
588 #endif
589 { SIGQUIT, "SIGQUIT" },
590 #ifdef SIGRECONFIG
591 { SIGRECONFIG, "SIGRECONFIG" },
592 #endif
593 #ifdef SIGRECOVERY
594 { SIGRECOVERY, "SIGRECOVERY" },
595 #endif
596 #ifdef SIGRESERVE
597 { SIGRESERVE, "SIGRESERVE" },
598 #endif
599 #ifdef SIGRETRACT
600 { SIGRETRACT, "SIGRETRACT" },
601 #endif
602 #ifdef SIGSAK
603 { SIGSAK, "SIGSAK" },
604 #endif
605 { SIGSEGV, "SIGSEGV" },
606 #ifdef SIGSOUND
607 { SIGSOUND, "SIGSOUND" },
608 #endif
609 { SIGSTOP, "SIGSTOP" },
610 { SIGSYS, "SIGSYS" },
611 #ifdef SIGSYSERROR
612 { SIGSYSERROR, "SIGSYSERROR" },
613 #endif
614 #ifdef SIGTALRM
615 { SIGTALRM, "SIGTALRM" },
616 #endif
617 { SIGTERM, "SIGTERM" },
618 #ifdef SIGTHAW
619 { SIGTHAW, "SIGTHAW" },
620 #endif
621 { SIGTRAP, "SIGTRAP" },
622 #ifdef SIGTSTP
623 { SIGTSTP, "SIGTSTP" },
624 #endif
625 { SIGTTIN, "SIGTTIN" },
626 { SIGTTOU, "SIGTTOU" },
627 #ifdef SIGURG
628 { SIGURG, "SIGURG" },
629 #endif
630 { SIGUSR1, "SIGUSR1" },
631 { SIGUSR2, "SIGUSR2" },
632 #ifdef SIGVIRT
633 { SIGVIRT, "SIGVIRT" },
634 #endif
635 { SIGVTALRM, "SIGVTALRM" },
636 #ifdef SIGWAITING
637 { SIGWAITING, "SIGWAITING" },
638 #endif
639 #ifdef SIGWINCH
640 { SIGWINCH, "SIGWINCH" },
641 #endif
642 #ifdef SIGWINDOW
643 { SIGWINDOW, "SIGWINDOW" },
644 #endif
645 { SIGXCPU, "SIGXCPU" },
646 { SIGXFSZ, "SIGXFSZ" },
647 #ifdef SIGXRES
648 { SIGXRES, "SIGXRES" },
649 #endif
650 { -1, NULL }
651 };
652
653 const char* ret = NULL;
654
655 #ifdef SIGRTMIN
656 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
657 if (sig == SIGRTMIN) {
658 ret = "SIGRTMIN";
659 } else if (sig == SIGRTMAX) {
660 ret = "SIGRTMAX";
661 } else {
662 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
663 return out;
664 }
665 }
666 #endif
667
668 if (sig > 0) {
669 for (int idx = 0; info[idx].sig != -1; idx ++) {
670 if (info[idx].sig == sig) {
671 ret = info[idx].name;
672 break;
673 }
674 }
675 }
676
677 if (!ret) {
678 if (!is_valid_signal(sig)) {
679 ret = "INVALID";
680 } else {
681 ret = "UNKNOWN";
682 }
683 }
684
685 if (out && outlen > 0) {
686 strncpy(out, ret, outlen);
687 out[outlen - 1] = '\0';
688 }
689 return out;
690 }
691
692 // Returns true if signal number is valid.
693 bool os::Posix::is_valid_signal(int sig) {
694 // MacOS not really POSIX compliant: sigaddset does not return
695 // an error for invalid signal numbers. However, MacOS does not
696 // support real time signals and simply seems to have just 33
697 // signals with no holes in the signal range.
698 #ifdef __APPLE__
699 return sig >= 1 && sig < NSIG;
700 #else
701 // Use sigaddset to check for signal validity.
702 sigset_t set;
703 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
704 return false;
705 }
706 return true;
707 #endif
708 }
709
710 #define NUM_IMPORTANT_SIGS 32
711 // Returns one-line short description of a signal set in a user provided buffer.
712 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
713 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
714 // Note: for shortness, just print out the first 32. That should
715 // cover most of the useful ones, apart from realtime signals.
716 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
717 const int rc = sigismember(set, sig);
718 if (rc == -1 && errno == EINVAL) {
719 buffer[sig-1] = '?';
720 } else {
721 buffer[sig-1] = rc == 0 ? '0' : '1';
722 }
723 }
724 buffer[NUM_IMPORTANT_SIGS] = 0;
725 return buffer;
726 }
727
728 // Prints one-line description of a signal set.
729 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
730 char buf[NUM_IMPORTANT_SIGS + 1];
731 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
732 st->print("%s", buf);
733 }
734
735 // Writes one-line description of a combination of sigaction.sa_flags into a user
736 // provided buffer. Returns that buffer.
737 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
738 char* p = buffer;
739 size_t remaining = size;
740 bool first = true;
741 int idx = 0;
742
743 assert(buffer, "invalid argument");
744
745 if (size == 0) {
746 return buffer;
747 }
748
749 strncpy(buffer, "none", size);
750
751 const struct {
752 int i;
753 const char* s;
754 } flaginfo [] = {
755 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
756 { SA_ONSTACK, "SA_ONSTACK" },
757 { SA_RESETHAND, "SA_RESETHAND" },
758 { SA_RESTART, "SA_RESTART" },
759 { SA_SIGINFO, "SA_SIGINFO" },
760 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
761 { SA_NODEFER, "SA_NODEFER" },
762 #ifdef AIX
763 { SA_ONSTACK, "SA_ONSTACK" },
764 { SA_OLDSTYLE, "SA_OLDSTYLE" },
765 #endif
766 { 0, NULL }
767 };
768
769 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
770 if (flags & flaginfo[idx].i) {
771 if (first) {
772 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
773 first = false;
774 } else {
775 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
776 }
777 const size_t len = strlen(p);
778 p += len;
779 remaining -= len;
780 }
781 }
782
783 buffer[size - 1] = '\0';
784
785 return buffer;
786 }
787
788 // Prints one-line description of a combination of sigaction.sa_flags.
789 void os::Posix::print_sa_flags(outputStream* st, int flags) {
790 char buffer[0x100];
791 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
792 st->print("%s", buffer);
793 }
794
795 // Helper function for os::Posix::print_siginfo_...():
796 // return a textual description for signal code.
797 struct enum_sigcode_desc_t {
798 const char* s_name;
799 const char* s_desc;
800 };
801
802 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
803
804 const struct {
805 int sig; int code; const char* s_code; const char* s_desc;
806 } t1 [] = {
807 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
808 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
809 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
810 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
811 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
812 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
813 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
814 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
815 #if defined(IA64) && defined(LINUX)
816 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
817 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
818 #endif
819 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
820 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
821 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
822 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
823 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
824 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
825 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
826 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
827 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
828 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
829 #ifdef AIX
830 // no explanation found what keyerr would be
831 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
832 #endif
833 #if defined(IA64) && !defined(AIX)
834 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
835 #endif
836 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
837 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
838 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
839 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
840 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
841 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
842 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
843 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
844 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
845 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
846 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
847 #ifdef SIGPOLL
848 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
849 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
850 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
851 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
852 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
853 #endif
854 { -1, -1, NULL, NULL }
855 };
856
857 // Codes valid in any signal context.
858 const struct {
859 int code; const char* s_code; const char* s_desc;
860 } t2 [] = {
861 { SI_USER, "SI_USER", "Signal sent by kill()." },
862 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
863 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
864 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
865 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
866 // Linux specific
867 #ifdef SI_TKILL
868 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
869 #endif
870 #ifdef SI_DETHREAD
871 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
872 #endif
873 #ifdef SI_KERNEL
874 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
875 #endif
876 #ifdef SI_SIGIO
877 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
878 #endif
879
880 #ifdef AIX
881 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
882 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
883 #endif
884
885 #ifdef __sun
886 { SI_NOINFO, "SI_NOINFO", "No signal information" },
887 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
888 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
889 #endif
890
891 { -1, NULL, NULL }
892 };
893
894 const char* s_code = NULL;
895 const char* s_desc = NULL;
896
897 for (int i = 0; t1[i].sig != -1; i ++) {
898 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
899 s_code = t1[i].s_code;
900 s_desc = t1[i].s_desc;
901 break;
902 }
903 }
904
905 if (s_code == NULL) {
906 for (int i = 0; t2[i].s_code != NULL; i ++) {
907 if (t2[i].code == si->si_code) {
908 s_code = t2[i].s_code;
909 s_desc = t2[i].s_desc;
910 }
911 }
912 }
913
914 if (s_code == NULL) {
915 out->s_name = "unknown";
916 out->s_desc = "unknown";
917 return false;
918 }
919
920 out->s_name = s_code;
921 out->s_desc = s_desc;
922
923 return true;
924 }
925
926 // A POSIX conform, platform-independend siginfo print routine.
927 // Short print out on one line.
928 void os::Posix::print_siginfo_brief(outputStream* os, const siginfo_t* si) {
929 char buf[20];
930 os->print("siginfo: ");
931
932 if (!si) {
933 os->print("<null>");
934 return;
935 }
936
937 // See print_siginfo_full() for details.
938 const int sig = si->si_signo;
939
940 os->print("si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
941
942 enum_sigcode_desc_t ed;
943 if (get_signal_code_description(si, &ed)) {
944 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
945 } else {
946 os->print(", si_code: %d (unknown)", si->si_code);
947 }
948
949 if (si->si_errno) {
950 os->print(", si_errno: %d", si->si_errno);
951 }
952
953 const int me = (int) ::getpid();
954 const int pid = (int) si->si_pid;
955
956 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
957 if (IS_VALID_PID(pid) && pid != me) {
958 os->print(", sent from pid: %d (uid: %d)", pid, (int) si->si_uid);
959 }
960 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
961 sig == SIGTRAP || sig == SIGFPE) {
962 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
963 #ifdef SIGPOLL
964 } else if (sig == SIGPOLL) {
965 os->print(", si_band: " PTR64_FORMAT, (uint64_t)si->si_band);
966 #endif
967 } else if (sig == SIGCHLD) {
968 os->print_cr(", si_pid: %d, si_uid: %d, si_status: %d", (int) si->si_pid, si->si_uid, si->si_status);
969 }
970 }
971
972 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
973 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
974 }
975
976 /*
977 * See the caveats for this class in os_posix.hpp
978 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
979 * method and returns false. If none of the signals are raised, returns true.
980 * The callback is supposed to provide the method that should be protected.
981 */
982 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
983 sigset_t saved_sig_mask;
984
985 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
986 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
987 "crash_protection already set?");
988
989 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
990 // since on at least some systems (OS X) siglongjmp will restore the mask
991 // for the process, not the thread
992 pthread_sigmask(0, NULL, &saved_sig_mask);
993 if (sigsetjmp(_jmpbuf, 0) == 0) {
994 // make sure we can see in the signal handler that we have crash protection
995 // installed
996 WatcherThread::watcher_thread()->set_crash_protection(this);
997 cb.call();
998 // and clear the crash protection
999 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1000 return true;
1001 }
1002 // this happens when we siglongjmp() back
1003 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1004 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1005 return false;
1006 }
1007
1008 void os::WatcherThreadCrashProtection::restore() {
1009 assert(WatcherThread::watcher_thread()->has_crash_protection(),
1010 "must have crash protection");
1011
1012 siglongjmp(_jmpbuf, 1);
1013 }
1014
1015 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1016 Thread* thread) {
1017
1018 if (thread != NULL &&
1019 thread->is_Watcher_thread() &&
1020 WatcherThread::watcher_thread()->has_crash_protection()) {
1021
1022 if (sig == SIGSEGV || sig == SIGBUS) {
1023 WatcherThread::watcher_thread()->crash_protection()->restore();
1024 }
1025 }
1026 }
1027
1028 #define check_with_errno(check_type, cond, msg) \
1029 do { \
1030 int err = errno; \
1031 check_type(cond, "%s; error='%s' (errno=%d)", msg, strerror(err), err); \
1032 } while (false)
1033
1034 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
1035 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
1036
1037 // POSIX unamed semaphores are not supported on OS X.
1038 #ifndef __APPLE__
1039
1040 PosixSemaphore::PosixSemaphore(uint value) {
1041 int ret = sem_init(&_semaphore, 0, value);
1042
1043 guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1044 }
1045
1046 PosixSemaphore::~PosixSemaphore() {
1047 sem_destroy(&_semaphore);
1048 }
1049
1050 void PosixSemaphore::signal(uint count) {
1051 for (uint i = 0; i < count; i++) {
1052 int ret = sem_post(&_semaphore);
1053
1054 assert_with_errno(ret == 0, "sem_post failed");
1055 }
1056 }
1057
1058 void PosixSemaphore::wait() {
1059 int ret;
1060
1061 do {
1062 ret = sem_wait(&_semaphore);
1063 } while (ret != 0 && errno == EINTR);
1064
1065 assert_with_errno(ret == 0, "sem_wait failed");
1066 }
1067
1068 bool PosixSemaphore::trywait() {
1069 int ret;
1070
1071 do {
1072 ret = sem_trywait(&_semaphore);
1073 } while (ret != 0 && errno == EINTR);
1074
1075 assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1076
1077 return ret == 0;
1078 }
1079
1080 bool PosixSemaphore::timedwait(struct timespec ts) {
1081 while (true) {
1082 int result = sem_timedwait(&_semaphore, &ts);
1083 if (result == 0) {
1084 return true;
1085 } else if (errno == EINTR) {
1086 continue;
1087 } else if (errno == ETIMEDOUT) {
1088 return false;
1089 } else {
1090 assert_with_errno(false, "timedwait failed");
1091 return false;
1092 }
1093 }
1094 }
1095
1096 #endif // __APPLE__