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 #ifndef PRODUCT
240 bool os::get_host_name(char* buf, size_t buflen) {
241 struct utsname name;
242 uname(&name);
243 jio_snprintf(buf, buflen, "%s", name.nodename);
244 return true;
245 }
246 #endif // PRODUCT
247
248 bool os::has_allocatable_memory_limit(julong* limit) {
249 struct rlimit rlim;
250 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
251 // if there was an error when calling getrlimit, assume that there is no limitation
252 // on virtual memory.
253 bool result;
254 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
255 result = false;
256 } else {
257 *limit = (julong)rlim.rlim_cur;
258 result = true;
259 }
260 #ifdef _LP64
261 return result;
262 #else
263 // arbitrary virtual space limit for 32 bit Unices found by testing. If
264 // getrlimit above returned a limit, bound it with this limit. Otherwise
265 // directly use it.
266 const julong max_virtual_limit = (julong)3800*M;
267 if (result) {
268 *limit = MIN2(*limit, max_virtual_limit);
269 } else {
270 *limit = max_virtual_limit;
271 }
272
273 // bound by actually allocatable memory. The algorithm uses two bounds, an
274 // upper and a lower limit. The upper limit is the current highest amount of
275 // memory that could not be allocated, the lower limit is the current highest
276 // amount of memory that could be allocated.
277 // The algorithm iteratively refines the result by halving the difference
278 // between these limits, updating either the upper limit (if that value could
279 // not be allocated) or the lower limit (if the that value could be allocated)
280 // until the difference between these limits is "small".
281
282 // the minimum amount of memory we care about allocating.
283 const julong min_allocation_size = M;
284
285 julong upper_limit = *limit;
286
287 // first check a few trivial cases
288 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
289 *limit = upper_limit;
290 } else if (!is_allocatable(min_allocation_size)) {
291 // we found that not even min_allocation_size is allocatable. Return it
292 // anyway. There is no point to search for a better value any more.
293 *limit = min_allocation_size;
294 } else {
295 // perform the binary search.
296 julong lower_limit = min_allocation_size;
297 while ((upper_limit - lower_limit) > min_allocation_size) {
298 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
299 temp_limit = align_size_down_(temp_limit, min_allocation_size);
300 if (is_allocatable(temp_limit)) {
301 lower_limit = temp_limit;
302 } else {
303 upper_limit = temp_limit;
304 }
305 }
306 *limit = lower_limit;
307 }
308 return true;
309 #endif
310 }
311
312 const char* os::get_current_directory(char *buf, size_t buflen) {
313 return getcwd(buf, buflen);
314 }
315
316 FILE* os::open(int fd, const char* mode) {
317 return ::fdopen(fd, mode);
318 }
319
320 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
321 // which is used to find statically linked in agents.
322 // Parameters:
323 // sym_name: Symbol in library we are looking for
324 // lib_name: Name of library to look in, NULL for shared libs.
325 // is_absolute_path == true if lib_name is absolute path to agent
326 // such as "/a/b/libL.so"
327 // == false if only the base name of the library is passed in
328 // such as "L"
329 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
330 bool is_absolute_path) {
331 char *agent_entry_name;
332 size_t len;
333 size_t name_len;
334 size_t prefix_len = strlen(JNI_LIB_PREFIX);
335 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
336 const char *start;
337
338 if (lib_name != NULL) {
339 len = name_len = strlen(lib_name);
340 if (is_absolute_path) {
341 // Need to strip path, prefix and suffix
342 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
343 lib_name = ++start;
344 }
345 if (len <= (prefix_len + suffix_len)) {
346 return NULL;
347 }
348 lib_name += prefix_len;
349 name_len = strlen(lib_name) - suffix_len;
350 }
351 }
352 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
353 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
354 if (agent_entry_name == NULL) {
355 return NULL;
356 }
357 strcpy(agent_entry_name, sym_name);
358 if (lib_name != NULL) {
359 strcat(agent_entry_name, "_");
360 strncat(agent_entry_name, lib_name, name_len);
361 }
362 return agent_entry_name;
363 }
364
365 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
366 assert(thread == Thread::current(), "thread consistency check");
367
368 ParkEvent * const slp = thread->_SleepEvent ;
369 slp->reset() ;
370 OrderAccess::fence() ;
371
372 if (interruptible) {
373 jlong prevtime = javaTimeNanos();
374
375 for (;;) {
376 if (os::is_interrupted(thread, true)) {
377 return OS_INTRPT;
378 }
379
380 jlong newtime = javaTimeNanos();
381
382 if (newtime - prevtime < 0) {
383 // time moving backwards, should only happen if no monotonic clock
384 // not a guarantee() because JVM should not abort on kernel/glibc bugs
385 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
386 } else {
387 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
388 }
389
390 if (millis <= 0) {
391 return OS_OK;
392 }
393
394 prevtime = newtime;
395
396 {
397 assert(thread->is_Java_thread(), "sanity check");
398 JavaThread *jt = (JavaThread *) thread;
399 ThreadBlockInVM tbivm(jt);
400 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
401
402 jt->set_suspend_equivalent();
403 // cleared by handle_special_suspend_equivalent_condition() or
404 // java_suspend_self() via check_and_wait_while_suspended()
405
406 slp->park(millis);
407
408 // were we externally suspended while we were waiting?
409 jt->check_and_wait_while_suspended();
410 }
411 }
412 } else {
413 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
414 jlong prevtime = javaTimeNanos();
415
416 for (;;) {
417 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
418 // the 1st iteration ...
419 jlong newtime = javaTimeNanos();
420
421 if (newtime - prevtime < 0) {
422 // time moving backwards, should only happen if no monotonic clock
423 // not a guarantee() because JVM should not abort on kernel/glibc bugs
424 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
425 } else {
426 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
427 }
428
429 if (millis <= 0) break ;
430
431 prevtime = newtime;
432 slp->park(millis);
433 }
434 return OS_OK ;
435 }
436 }
437
438 ////////////////////////////////////////////////////////////////////////////////
439 // interrupt support
440
441 void os::interrupt(Thread* thread) {
442 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
443 "possibility of dangling Thread pointer");
444
445 OSThread* osthread = thread->osthread();
446
447 if (!osthread->interrupted()) {
448 osthread->set_interrupted(true);
449 // More than one thread can get here with the same value of osthread,
450 // resulting in multiple notifications. We do, however, want the store
451 // to interrupted() to be visible to other threads before we execute unpark().
452 OrderAccess::fence();
453 ParkEvent * const slp = thread->_SleepEvent ;
454 if (slp != NULL) slp->unpark() ;
455 }
456
457 // For JSR166. Unpark even if interrupt status already was set
458 if (thread->is_Java_thread())
459 ((JavaThread*)thread)->parker()->unpark();
460
461 ParkEvent * ev = thread->_ParkEvent ;
462 if (ev != NULL) ev->unpark() ;
463
464 }
465
466 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
467 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
468 "possibility of dangling Thread pointer");
469
470 OSThread* osthread = thread->osthread();
471
472 bool interrupted = osthread->interrupted();
473
474 // NOTE that since there is no "lock" around the interrupt and
475 // is_interrupted operations, there is the possibility that the
476 // interrupted flag (in osThread) will be "false" but that the
477 // low-level events will be in the signaled state. This is
478 // intentional. The effect of this is that Object.wait() and
479 // LockSupport.park() will appear to have a spurious wakeup, which
480 // is allowed and not harmful, and the possibility is so rare that
481 // it is not worth the added complexity to add yet another lock.
482 // For the sleep event an explicit reset is performed on entry
483 // to os::sleep, so there is no early return. It has also been
484 // recommended not to put the interrupted flag into the "event"
485 // structure because it hides the issue.
486 if (interrupted && clear_interrupted) {
487 osthread->set_interrupted(false);
488 // consider thread->_SleepEvent->reset() ... optional optimization
489 }
490
491 return interrupted;
492 }
493
494 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
495 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
496
497 static const struct {
498 int sig; const char* name;
499 }
500 info[] =
501 {
502 { SIGABRT, "SIGABRT" },
503 #ifdef SIGAIO
504 { SIGAIO, "SIGAIO" },
505 #endif
506 { SIGALRM, "SIGALRM" },
507 #ifdef SIGALRM1
508 { SIGALRM1, "SIGALRM1" },
509 #endif
510 { SIGBUS, "SIGBUS" },
511 #ifdef SIGCANCEL
512 { SIGCANCEL, "SIGCANCEL" },
513 #endif
514 { SIGCHLD, "SIGCHLD" },
515 #ifdef SIGCLD
516 { SIGCLD, "SIGCLD" },
517 #endif
518 { SIGCONT, "SIGCONT" },
519 #ifdef SIGCPUFAIL
520 { SIGCPUFAIL, "SIGCPUFAIL" },
521 #endif
522 #ifdef SIGDANGER
523 { SIGDANGER, "SIGDANGER" },
524 #endif
525 #ifdef SIGDIL
526 { SIGDIL, "SIGDIL" },
527 #endif
528 #ifdef SIGEMT
529 { SIGEMT, "SIGEMT" },
530 #endif
531 { SIGFPE, "SIGFPE" },
532 #ifdef SIGFREEZE
533 { SIGFREEZE, "SIGFREEZE" },
534 #endif
535 #ifdef SIGGFAULT
536 { SIGGFAULT, "SIGGFAULT" },
537 #endif
538 #ifdef SIGGRANT
539 { SIGGRANT, "SIGGRANT" },
540 #endif
541 { SIGHUP, "SIGHUP" },
542 { SIGILL, "SIGILL" },
543 { SIGINT, "SIGINT" },
544 #ifdef SIGIO
545 { SIGIO, "SIGIO" },
546 #endif
547 #ifdef SIGIOINT
548 { SIGIOINT, "SIGIOINT" },
549 #endif
550 #ifdef SIGIOT
551 // SIGIOT is there for BSD compatibility, but on most Unices just a
552 // synonym for SIGABRT. The result should be "SIGABRT", not
553 // "SIGIOT".
554 #if (SIGIOT != SIGABRT )
555 { SIGIOT, "SIGIOT" },
556 #endif
557 #endif
558 #ifdef SIGKAP
559 { SIGKAP, "SIGKAP" },
560 #endif
561 { SIGKILL, "SIGKILL" },
562 #ifdef SIGLOST
563 { SIGLOST, "SIGLOST" },
564 #endif
565 #ifdef SIGLWP
566 { SIGLWP, "SIGLWP" },
567 #endif
568 #ifdef SIGLWPTIMER
569 { SIGLWPTIMER, "SIGLWPTIMER" },
570 #endif
571 #ifdef SIGMIGRATE
572 { SIGMIGRATE, "SIGMIGRATE" },
573 #endif
574 #ifdef SIGMSG
575 { SIGMSG, "SIGMSG" },
576 #endif
577 { SIGPIPE, "SIGPIPE" },
578 #ifdef SIGPOLL
579 { SIGPOLL, "SIGPOLL" },
580 #endif
581 #ifdef SIGPRE
582 { SIGPRE, "SIGPRE" },
583 #endif
584 { SIGPROF, "SIGPROF" },
585 #ifdef SIGPTY
586 { SIGPTY, "SIGPTY" },
587 #endif
588 #ifdef SIGPWR
589 { SIGPWR, "SIGPWR" },
590 #endif
591 { SIGQUIT, "SIGQUIT" },
592 #ifdef SIGRECONFIG
593 { SIGRECONFIG, "SIGRECONFIG" },
594 #endif
595 #ifdef SIGRECOVERY
596 { SIGRECOVERY, "SIGRECOVERY" },
597 #endif
598 #ifdef SIGRESERVE
599 { SIGRESERVE, "SIGRESERVE" },
600 #endif
601 #ifdef SIGRETRACT
602 { SIGRETRACT, "SIGRETRACT" },
603 #endif
604 #ifdef SIGSAK
605 { SIGSAK, "SIGSAK" },
606 #endif
607 { SIGSEGV, "SIGSEGV" },
608 #ifdef SIGSOUND
609 { SIGSOUND, "SIGSOUND" },
610 #endif
611 { SIGSTOP, "SIGSTOP" },
612 { SIGSYS, "SIGSYS" },
613 #ifdef SIGSYSERROR
614 { SIGSYSERROR, "SIGSYSERROR" },
615 #endif
616 #ifdef SIGTALRM
617 { SIGTALRM, "SIGTALRM" },
618 #endif
619 { SIGTERM, "SIGTERM" },
620 #ifdef SIGTHAW
621 { SIGTHAW, "SIGTHAW" },
622 #endif
623 { SIGTRAP, "SIGTRAP" },
624 #ifdef SIGTSTP
625 { SIGTSTP, "SIGTSTP" },
626 #endif
627 { SIGTTIN, "SIGTTIN" },
628 { SIGTTOU, "SIGTTOU" },
629 #ifdef SIGURG
630 { SIGURG, "SIGURG" },
631 #endif
632 { SIGUSR1, "SIGUSR1" },
633 { SIGUSR2, "SIGUSR2" },
634 #ifdef SIGVIRT
635 { SIGVIRT, "SIGVIRT" },
636 #endif
637 { SIGVTALRM, "SIGVTALRM" },
638 #ifdef SIGWAITING
639 { SIGWAITING, "SIGWAITING" },
640 #endif
641 #ifdef SIGWINCH
642 { SIGWINCH, "SIGWINCH" },
643 #endif
644 #ifdef SIGWINDOW
645 { SIGWINDOW, "SIGWINDOW" },
646 #endif
647 { SIGXCPU, "SIGXCPU" },
648 { SIGXFSZ, "SIGXFSZ" },
649 #ifdef SIGXRES
650 { SIGXRES, "SIGXRES" },
651 #endif
652 { -1, NULL }
653 };
654
655 const char* ret = NULL;
656
657 #ifdef SIGRTMIN
658 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
659 if (sig == SIGRTMIN) {
660 ret = "SIGRTMIN";
661 } else if (sig == SIGRTMAX) {
662 ret = "SIGRTMAX";
663 } else {
664 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
665 return out;
666 }
667 }
668 #endif
669
670 if (sig > 0) {
671 for (int idx = 0; info[idx].sig != -1; idx ++) {
672 if (info[idx].sig == sig) {
673 ret = info[idx].name;
674 break;
675 }
676 }
677 }
678
679 if (!ret) {
680 if (!is_valid_signal(sig)) {
681 ret = "INVALID";
682 } else {
683 ret = "UNKNOWN";
684 }
685 }
686
687 if (out && outlen > 0) {
688 strncpy(out, ret, outlen);
689 out[outlen - 1] = '\0';
690 }
691 return out;
692 }
693
694 // Returns true if signal number is valid.
695 bool os::Posix::is_valid_signal(int sig) {
696 // MacOS not really POSIX compliant: sigaddset does not return
697 // an error for invalid signal numbers. However, MacOS does not
698 // support real time signals and simply seems to have just 33
699 // signals with no holes in the signal range.
700 #ifdef __APPLE__
701 return sig >= 1 && sig < NSIG;
702 #else
703 // Use sigaddset to check for signal validity.
704 sigset_t set;
705 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
706 return false;
707 }
708 return true;
709 #endif
710 }
711
712 #define NUM_IMPORTANT_SIGS 32
713 // Returns one-line short description of a signal set in a user provided buffer.
714 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
715 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
716 // Note: for shortness, just print out the first 32. That should
717 // cover most of the useful ones, apart from realtime signals.
718 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
719 const int rc = sigismember(set, sig);
720 if (rc == -1 && errno == EINVAL) {
721 buffer[sig-1] = '?';
722 } else {
723 buffer[sig-1] = rc == 0 ? '0' : '1';
724 }
725 }
726 buffer[NUM_IMPORTANT_SIGS] = 0;
727 return buffer;
728 }
729
730 // Prints one-line description of a signal set.
731 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
732 char buf[NUM_IMPORTANT_SIGS + 1];
733 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
734 st->print("%s", buf);
735 }
736
737 // Writes one-line description of a combination of sigaction.sa_flags into a user
738 // provided buffer. Returns that buffer.
739 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
740 char* p = buffer;
741 size_t remaining = size;
742 bool first = true;
743 int idx = 0;
744
745 assert(buffer, "invalid argument");
746
747 if (size == 0) {
748 return buffer;
749 }
750
751 strncpy(buffer, "none", size);
752
753 const struct {
754 int i;
755 const char* s;
756 } flaginfo [] = {
757 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
758 { SA_ONSTACK, "SA_ONSTACK" },
759 { SA_RESETHAND, "SA_RESETHAND" },
760 { SA_RESTART, "SA_RESTART" },
761 { SA_SIGINFO, "SA_SIGINFO" },
762 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
763 { SA_NODEFER, "SA_NODEFER" },
764 #ifdef AIX
765 { SA_ONSTACK, "SA_ONSTACK" },
766 { SA_OLDSTYLE, "SA_OLDSTYLE" },
767 #endif
768 { 0, NULL }
769 };
770
771 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
772 if (flags & flaginfo[idx].i) {
773 if (first) {
774 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
775 first = false;
776 } else {
777 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
778 }
779 const size_t len = strlen(p);
780 p += len;
781 remaining -= len;
782 }
783 }
784
785 buffer[size - 1] = '\0';
786
787 return buffer;
788 }
789
790 // Prints one-line description of a combination of sigaction.sa_flags.
791 void os::Posix::print_sa_flags(outputStream* st, int flags) {
792 char buffer[0x100];
793 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
794 st->print("%s", buffer);
795 }
796
797 // Helper function for os::Posix::print_siginfo_...():
798 // return a textual description for signal code.
799 struct enum_sigcode_desc_t {
800 const char* s_name;
801 const char* s_desc;
802 };
803
804 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
805
806 const struct {
807 int sig; int code; const char* s_code; const char* s_desc;
808 } t1 [] = {
809 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
810 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
811 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
812 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
813 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
814 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
815 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
816 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
817 #if defined(IA64) && defined(LINUX)
818 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
819 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
820 #endif
821 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
822 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
823 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
824 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
825 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
826 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
827 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
828 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
829 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
830 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
831 #ifdef AIX
832 // no explanation found what keyerr would be
833 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
834 #endif
835 #if defined(IA64) && !defined(AIX)
836 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
837 #endif
838 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
839 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
840 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
841 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
842 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
843 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
844 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
845 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
846 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
847 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
848 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
849 #ifdef SIGPOLL
850 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
851 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
852 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
853 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
854 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
855 #endif
856 { -1, -1, NULL, NULL }
857 };
858
859 // Codes valid in any signal context.
860 const struct {
861 int code; const char* s_code; const char* s_desc;
862 } t2 [] = {
863 { SI_USER, "SI_USER", "Signal sent by kill()." },
864 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
865 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
866 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
867 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
868 // Linux specific
869 #ifdef SI_TKILL
870 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
871 #endif
872 #ifdef SI_DETHREAD
873 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
874 #endif
875 #ifdef SI_KERNEL
876 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
877 #endif
878 #ifdef SI_SIGIO
879 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
880 #endif
881
882 #ifdef AIX
883 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
884 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
885 #endif
886
887 #ifdef __sun
888 { SI_NOINFO, "SI_NOINFO", "No signal information" },
889 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
890 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
891 #endif
892
893 { -1, NULL, NULL }
894 };
895
896 const char* s_code = NULL;
897 const char* s_desc = NULL;
898
899 for (int i = 0; t1[i].sig != -1; i ++) {
900 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
901 s_code = t1[i].s_code;
902 s_desc = t1[i].s_desc;
903 break;
904 }
905 }
906
907 if (s_code == NULL) {
908 for (int i = 0; t2[i].s_code != NULL; i ++) {
909 if (t2[i].code == si->si_code) {
910 s_code = t2[i].s_code;
911 s_desc = t2[i].s_desc;
912 }
913 }
914 }
915
916 if (s_code == NULL) {
917 out->s_name = "unknown";
918 out->s_desc = "unknown";
919 return false;
920 }
921
922 out->s_name = s_code;
923 out->s_desc = s_desc;
924
925 return true;
926 }
927
928 // A POSIX conform, platform-independend siginfo print routine.
929 // Short print out on one line.
930 void os::Posix::print_siginfo_brief(outputStream* os, const siginfo_t* si) {
931 char buf[20];
932 os->print("siginfo: ");
933
934 if (!si) {
935 os->print("<null>");
936 return;
937 }
938
939 // See print_siginfo_full() for details.
940 const int sig = si->si_signo;
941
942 os->print("si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
943
944 enum_sigcode_desc_t ed;
945 if (get_signal_code_description(si, &ed)) {
946 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
947 } else {
948 os->print(", si_code: %d (unknown)", si->si_code);
949 }
950
951 if (si->si_errno) {
952 os->print(", si_errno: %d", si->si_errno);
953 }
954
955 const int me = (int) ::getpid();
956 const int pid = (int) si->si_pid;
957
958 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
959 if (IS_VALID_PID(pid) && pid != me) {
960 os->print(", sent from pid: %d (uid: %d)", pid, (int) si->si_uid);
961 }
962 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
963 sig == SIGTRAP || sig == SIGFPE) {
964 os->print(", si_addr: " PTR_FORMAT, si->si_addr);
965 #ifdef SIGPOLL
966 } else if (sig == SIGPOLL) {
967 os->print(", si_band: " PTR64_FORMAT, (uint64_t)si->si_band);
968 #endif
969 } else if (sig == SIGCHLD) {
970 os->print_cr(", si_pid: %d, si_uid: %d, si_status: %d", (int) si->si_pid, si->si_uid, si->si_status);
971 }
972 }
973
974 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
975 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
976 }
977
978 /*
979 * See the caveats for this class in os_posix.hpp
980 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
981 * method and returns false. If none of the signals are raised, returns true.
982 * The callback is supposed to provide the method that should be protected.
983 */
984 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
985 sigset_t saved_sig_mask;
986
987 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
988 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
989 "crash_protection already set?");
990
991 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
992 // since on at least some systems (OS X) siglongjmp will restore the mask
993 // for the process, not the thread
994 pthread_sigmask(0, NULL, &saved_sig_mask);
995 if (sigsetjmp(_jmpbuf, 0) == 0) {
996 // make sure we can see in the signal handler that we have crash protection
997 // installed
998 WatcherThread::watcher_thread()->set_crash_protection(this);
999 cb.call();
1000 // and clear the crash protection
1001 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1002 return true;
1003 }
1004 // this happens when we siglongjmp() back
1005 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1006 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1007 return false;
1008 }
1009
1010 void os::WatcherThreadCrashProtection::restore() {
1011 assert(WatcherThread::watcher_thread()->has_crash_protection(),
1012 "must have crash protection");
1013
1014 siglongjmp(_jmpbuf, 1);
1015 }
1016
1017 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1018 Thread* thread) {
1019
1020 if (thread != NULL &&
1021 thread->is_Watcher_thread() &&
1022 WatcherThread::watcher_thread()->has_crash_protection()) {
1023
1024 if (sig == SIGSEGV || sig == SIGBUS) {
1025 WatcherThread::watcher_thread()->crash_protection()->restore();
1026 }
1027 }
1028 }
1029
1030 #define check_with_errno(check_type, cond, msg) \
1031 do { \
1032 int err = errno; \
1033 check_type(cond, "%s; error='%s' (errno=%d)", msg, strerror(err), err); \
1034 } while (false)
1035
1036 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
1037 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
1038
1039 // POSIX unamed semaphores are not supported on OS X.
1040 #ifndef __APPLE__
1041
1042 PosixSemaphore::PosixSemaphore(uint value) {
1043 int ret = sem_init(&_semaphore, 0, value);
1044
1045 guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1046 }
1047
1048 PosixSemaphore::~PosixSemaphore() {
1049 sem_destroy(&_semaphore);
1050 }
1051
1052 void PosixSemaphore::signal(uint count) {
1053 for (uint i = 0; i < count; i++) {
1054 int ret = sem_post(&_semaphore);
1055
1056 assert_with_errno(ret == 0, "sem_post failed");
1057 }
1058 }
1059
1060 void PosixSemaphore::wait() {
1061 int ret;
1062
1063 do {
1064 ret = sem_wait(&_semaphore);
1065 } while (ret != 0 && errno == EINTR);
1066
1067 assert_with_errno(ret == 0, "sem_wait failed");
1068 }
1069
1070 bool PosixSemaphore::trywait() {
1071 int ret;
1072
1073 do {
1074 ret = sem_trywait(&_semaphore);
1075 } while (ret != 0 && errno == EINTR);
1076
1077 assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1078
1079 return ret == 0;
1080 }
1081
1082 bool PosixSemaphore::timedwait(struct timespec ts) {
1083 while (true) {
1084 int result = sem_timedwait(&_semaphore, &ts);
1085 if (result == 0) {
1086 return true;
1087 } else if (errno == EINTR) {
1088 continue;
1089 } else if (errno == ETIMEDOUT) {
1090 return false;
1091 } else {
1092 assert_with_errno(false, "timedwait failed");
1093 return false;
1094 }
1095 }
1096 }
1097
1098 #endif // __APPLE__