1 /*
2 * Copyright (c) 1999, 2014, 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 "runtime/frame.inline.hpp"
28 #include "runtime/interfaceSupport.hpp"
29 #include "runtime/os.hpp"
30 #include "utilities/vmError.hpp"
31
32 #include <signal.h>
33 #include <unistd.h>
34 #include <sys/resource.h>
35 #include <sys/utsname.h>
36 #include <pthread.h>
37 #include <signal.h>
38
39 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
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_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize) {
50 int n;
51 struct rlimit rlim;
52 bool success;
53
54 n = get_core_path(buffer, bufferSize);
55
56 if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
57 jio_snprintf(buffer + n, bufferSize - n, "/core or core.%d (may not exist)", current_process_id());
58 success = true;
59 } else {
60 switch(rlim.rlim_cur) {
61 case RLIM_INFINITY:
62 jio_snprintf(buffer + n, bufferSize - n, "/core or core.%d", current_process_id());
63 success = true;
64 break;
65 case 0:
66 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
67 success = false;
68 break;
69 default:
70 jio_snprintf(buffer + n, bufferSize - n, "/core or core.%d (max size %lu kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", current_process_id(), (unsigned long)(rlim.rlim_cur >> 10));
71 success = true;
72 break;
73 }
74 }
75 VMError::report_coredump_status(buffer, success);
76 }
77
78 address os::get_caller_pc(int n) {
79 #ifdef _NMT_NOINLINE_
80 n ++;
81 #endif
82 frame fr = os::current_frame();
83 while (n > 0 && fr.pc() &&
84 !os::is_first_C_frame(&fr) && fr.sender_pc()) {
85 fr = os::get_sender_for_C_frame(&fr);
86 n --;
87 }
88 if (n == 0) {
89 return fr.pc();
90 } else {
91 return NULL;
92 }
93 }
94
95 int os::get_last_error() {
96 return errno;
97 }
98
99 bool os::is_debugger_attached() {
100 // not implemented
101 return false;
102 }
103
104 void os::wait_for_keypress_at_exit(void) {
105 // don't do anything on posix platforms
106 return;
107 }
108
109 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
110 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
111 // rather than unmapping and remapping the whole chunk to get requested alignment.
112 char* os::reserve_memory_aligned(size_t size, size_t alignment) {
113 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
114 "Alignment must be a multiple of allocation granularity (page size)");
115 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
116
117 size_t extra_size = size + alignment;
118 assert(extra_size >= size, "overflow, size is too large to allow alignment");
119
120 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
121
122 if (extra_base == NULL) {
123 return NULL;
124 }
125
126 // Do manual alignment
127 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
128
129 // [ | | ]
130 // ^ extra_base
131 // ^ extra_base + begin_offset == aligned_base
132 // extra_base + begin_offset + size ^
133 // extra_base + extra_size ^
134 // |<>| == begin_offset
135 // end_offset == |<>|
136 size_t begin_offset = aligned_base - extra_base;
137 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
138
139 if (begin_offset > 0) {
140 os::release_memory(extra_base, begin_offset);
141 }
142
143 if (end_offset > 0) {
144 os::release_memory(extra_base + begin_offset + size, end_offset);
145 }
146
147 return aligned_base;
148 }
149
150 void os::Posix::print_load_average(outputStream* st) {
151 st->print("load average:");
152 double loadavg[3];
153 os::loadavg(loadavg, 3);
154 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
155 st->cr();
156 }
157
158 void os::Posix::print_rlimit_info(outputStream* st) {
159 st->print("rlimit:");
160 struct rlimit rlim;
161
162 st->print(" STACK ");
163 getrlimit(RLIMIT_STACK, &rlim);
164 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
165 else st->print("%uk", rlim.rlim_cur >> 10);
166
167 st->print(", CORE ");
168 getrlimit(RLIMIT_CORE, &rlim);
169 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
170 else st->print("%uk", rlim.rlim_cur >> 10);
171
172 // Isn't there on solaris
173 #if !defined(TARGET_OS_FAMILY_solaris) && !defined(TARGET_OS_FAMILY_aix)
174 st->print(", NPROC ");
175 getrlimit(RLIMIT_NPROC, &rlim);
176 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
177 else st->print("%d", rlim.rlim_cur);
178 #endif
179
180 st->print(", NOFILE ");
181 getrlimit(RLIMIT_NOFILE, &rlim);
182 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
183 else st->print("%d", rlim.rlim_cur);
184
185 st->print(", AS ");
186 getrlimit(RLIMIT_AS, &rlim);
187 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
188 else st->print("%uk", rlim.rlim_cur >> 10);
189 st->cr();
190 }
191
192 void os::Posix::print_uname_info(outputStream* st) {
193 // kernel
194 st->print("uname:");
195 struct utsname name;
196 uname(&name);
197 st->print("%s ", name.sysname);
198 st->print("%s ", name.release);
199 st->print("%s ", name.version);
200 st->print_raw(name.machine);
201 st->cr();
202 }
203
204 bool os::has_allocatable_memory_limit(julong* limit) {
205 struct rlimit rlim;
206 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
207 // if there was an error when calling getrlimit, assume that there is no limitation
208 // on virtual memory.
209 bool result;
210 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
211 result = false;
212 } else {
213 *limit = (julong)rlim.rlim_cur;
214 result = true;
215 }
216 #ifdef _LP64
217 return result;
218 #else
219 // arbitrary virtual space limit for 32 bit Unices found by testing. If
220 // getrlimit above returned a limit, bound it with this limit. Otherwise
221 // directly use it.
222 const julong max_virtual_limit = (julong)3800*M;
223 if (result) {
224 *limit = MIN2(*limit, max_virtual_limit);
225 } else {
226 *limit = max_virtual_limit;
227 }
228
229 // bound by actually allocatable memory. The algorithm uses two bounds, an
230 // upper and a lower limit. The upper limit is the current highest amount of
231 // memory that could not be allocated, the lower limit is the current highest
232 // amount of memory that could be allocated.
233 // The algorithm iteratively refines the result by halving the difference
234 // between these limits, updating either the upper limit (if that value could
235 // not be allocated) or the lower limit (if the that value could be allocated)
236 // until the difference between these limits is "small".
237
238 // the minimum amount of memory we care about allocating.
239 const julong min_allocation_size = M;
240
241 julong upper_limit = *limit;
242
243 // first check a few trivial cases
244 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
245 *limit = upper_limit;
246 } else if (!is_allocatable(min_allocation_size)) {
247 // we found that not even min_allocation_size is allocatable. Return it
248 // anyway. There is no point to search for a better value any more.
249 *limit = min_allocation_size;
250 } else {
251 // perform the binary search.
252 julong lower_limit = min_allocation_size;
253 while ((upper_limit - lower_limit) > min_allocation_size) {
254 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
255 temp_limit = align_size_down_(temp_limit, min_allocation_size);
256 if (is_allocatable(temp_limit)) {
257 lower_limit = temp_limit;
258 } else {
259 upper_limit = temp_limit;
260 }
261 }
262 *limit = lower_limit;
263 }
264 return true;
265 #endif
266 }
267
268 const char* os::get_current_directory(char *buf, size_t buflen) {
269 return getcwd(buf, buflen);
270 }
271
272 FILE* os::open(int fd, const char* mode) {
273 return ::fdopen(fd, mode);
274 }
275
276 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
277 // which is used to find statically linked in agents.
278 // Parameters:
279 // sym_name: Symbol in library we are looking for
280 // lib_name: Name of library to look in, NULL for shared libs.
281 // is_absolute_path == true if lib_name is absolute path to agent
282 // such as "/a/b/libL.so"
283 // == false if only the base name of the library is passed in
284 // such as "L"
285 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
286 bool is_absolute_path) {
287 char *agent_entry_name;
288 size_t len;
289 size_t name_len;
290 size_t prefix_len = strlen(JNI_LIB_PREFIX);
291 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
292 const char *start;
293
294 if (lib_name != NULL) {
295 len = name_len = strlen(lib_name);
296 if (is_absolute_path) {
297 // Need to strip path, prefix and suffix
298 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
299 lib_name = ++start;
300 }
301 if (len <= (prefix_len + suffix_len)) {
302 return NULL;
303 }
304 lib_name += prefix_len;
305 name_len = strlen(lib_name) - suffix_len;
306 }
307 }
308 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
309 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
310 if (agent_entry_name == NULL) {
311 return NULL;
312 }
313 strcpy(agent_entry_name, sym_name);
314 if (lib_name != NULL) {
315 strcat(agent_entry_name, "_");
316 strncat(agent_entry_name, lib_name, name_len);
317 }
318 return agent_entry_name;
319 }
320
321 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
322 assert(thread == Thread::current(), "thread consistency check");
323
324 ParkEvent * const slp = thread->_SleepEvent ;
325 slp->reset() ;
326 OrderAccess::fence() ;
327
328 if (interruptible) {
329 jlong prevtime = javaTimeNanos();
330
331 for (;;) {
332 if (os::is_interrupted(thread, true)) {
333 return OS_INTRPT;
334 }
335
336 jlong newtime = javaTimeNanos();
337
338 if (newtime - prevtime < 0) {
339 // time moving backwards, should only happen if no monotonic clock
340 // not a guarantee() because JVM should not abort on kernel/glibc bugs
341 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
342 } else {
343 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
344 }
345
346 if (millis <= 0) {
347 return OS_OK;
348 }
349
350 prevtime = newtime;
351
352 {
353 assert(thread->is_Java_thread(), "sanity check");
354 JavaThread *jt = (JavaThread *) thread;
355 ThreadBlockInVM tbivm(jt);
356 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
357
358 jt->set_suspend_equivalent();
359 // cleared by handle_special_suspend_equivalent_condition() or
360 // java_suspend_self() via check_and_wait_while_suspended()
361
362 slp->park(millis);
363
364 // were we externally suspended while we were waiting?
365 jt->check_and_wait_while_suspended();
366 }
367 }
368 } else {
369 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
370 jlong prevtime = javaTimeNanos();
371
372 for (;;) {
373 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
374 // the 1st iteration ...
375 jlong newtime = javaTimeNanos();
376
377 if (newtime - prevtime < 0) {
378 // time moving backwards, should only happen if no monotonic clock
379 // not a guarantee() because JVM should not abort on kernel/glibc bugs
380 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
381 } else {
382 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
383 }
384
385 if (millis <= 0) break ;
386
387 prevtime = newtime;
388 slp->park(millis);
389 }
390 return OS_OK ;
391 }
392 }
393
394 ////////////////////////////////////////////////////////////////////////////////
395 // interrupt support
396
397 void os::interrupt(Thread* thread) {
398 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
399 "possibility of dangling Thread pointer");
400
401 OSThread* osthread = thread->osthread();
402
403 if (!osthread->interrupted()) {
404 osthread->set_interrupted(true);
405 // More than one thread can get here with the same value of osthread,
406 // resulting in multiple notifications. We do, however, want the store
407 // to interrupted() to be visible to other threads before we execute unpark().
408 OrderAccess::fence();
409 ParkEvent * const slp = thread->_SleepEvent ;
410 if (slp != NULL) slp->unpark() ;
411 }
412
413 // For JSR166. Unpark even if interrupt status already was set
414 if (thread->is_Java_thread())
415 ((JavaThread*)thread)->parker()->unpark();
416
417 ParkEvent * ev = thread->_ParkEvent ;
418 if (ev != NULL) ev->unpark() ;
419
420 }
421
422 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
423 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
424 "possibility of dangling Thread pointer");
425
426 OSThread* osthread = thread->osthread();
427
428 bool interrupted = osthread->interrupted();
429
430 // NOTE that since there is no "lock" around the interrupt and
431 // is_interrupted operations, there is the possibility that the
432 // interrupted flag (in osThread) will be "false" but that the
433 // low-level events will be in the signaled state. This is
434 // intentional. The effect of this is that Object.wait() and
435 // LockSupport.park() will appear to have a spurious wakeup, which
436 // is allowed and not harmful, and the possibility is so rare that
437 // it is not worth the added complexity to add yet another lock.
438 // For the sleep event an explicit reset is performed on entry
439 // to os::sleep, so there is no early return. It has also been
440 // recommended not to put the interrupted flag into the "event"
441 // structure because it hides the issue.
442 if (interrupted && clear_interrupted) {
443 osthread->set_interrupted(false);
444 // consider thread->_SleepEvent->reset() ... optional optimization
445 }
446
447 return interrupted;
448 }
449
450 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
451 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
452
453 static const struct {
454 int sig; const char* name;
455 }
456 info[] =
457 {
458 { SIGABRT, "SIGABRT" },
459 #ifdef SIGAIO
460 { SIGAIO, "SIGAIO" },
461 #endif
462 { SIGALRM, "SIGALRM" },
463 #ifdef SIGALRM1
464 { SIGALRM1, "SIGALRM1" },
465 #endif
466 { SIGBUS, "SIGBUS" },
467 #ifdef SIGCANCEL
468 { SIGCANCEL, "SIGCANCEL" },
469 #endif
470 { SIGCHLD, "SIGCHLD" },
471 #ifdef SIGCLD
472 { SIGCLD, "SIGCLD" },
473 #endif
474 { SIGCONT, "SIGCONT" },
475 #ifdef SIGCPUFAIL
476 { SIGCPUFAIL, "SIGCPUFAIL" },
477 #endif
478 #ifdef SIGDANGER
479 { SIGDANGER, "SIGDANGER" },
480 #endif
481 #ifdef SIGDIL
482 { SIGDIL, "SIGDIL" },
483 #endif
484 #ifdef SIGEMT
485 { SIGEMT, "SIGEMT" },
486 #endif
487 { SIGFPE, "SIGFPE" },
488 #ifdef SIGFREEZE
489 { SIGFREEZE, "SIGFREEZE" },
490 #endif
491 #ifdef SIGGFAULT
492 { SIGGFAULT, "SIGGFAULT" },
493 #endif
494 #ifdef SIGGRANT
495 { SIGGRANT, "SIGGRANT" },
496 #endif
497 { SIGHUP, "SIGHUP" },
498 { SIGILL, "SIGILL" },
499 { SIGINT, "SIGINT" },
500 #ifdef SIGIO
501 { SIGIO, "SIGIO" },
502 #endif
503 #ifdef SIGIOINT
504 { SIGIOINT, "SIGIOINT" },
505 #endif
506 #ifdef SIGIOT
507 // SIGIOT is there for BSD compatibility, but on most Unices just a
508 // synonym for SIGABRT. The result should be "SIGABRT", not
509 // "SIGIOT".
510 #if (SIGIOT != SIGABRT )
511 { SIGIOT, "SIGIOT" },
512 #endif
513 #endif
514 #ifdef SIGKAP
515 { SIGKAP, "SIGKAP" },
516 #endif
517 { SIGKILL, "SIGKILL" },
518 #ifdef SIGLOST
519 { SIGLOST, "SIGLOST" },
520 #endif
521 #ifdef SIGLWP
522 { SIGLWP, "SIGLWP" },
523 #endif
524 #ifdef SIGLWPTIMER
525 { SIGLWPTIMER, "SIGLWPTIMER" },
526 #endif
527 #ifdef SIGMIGRATE
528 { SIGMIGRATE, "SIGMIGRATE" },
529 #endif
530 #ifdef SIGMSG
531 { SIGMSG, "SIGMSG" },
532 #endif
533 { SIGPIPE, "SIGPIPE" },
534 #ifdef SIGPOLL
535 { SIGPOLL, "SIGPOLL" },
536 #endif
537 #ifdef SIGPRE
538 { SIGPRE, "SIGPRE" },
539 #endif
540 { SIGPROF, "SIGPROF" },
541 #ifdef SIGPTY
542 { SIGPTY, "SIGPTY" },
543 #endif
544 #ifdef SIGPWR
545 { SIGPWR, "SIGPWR" },
546 #endif
547 { SIGQUIT, "SIGQUIT" },
548 #ifdef SIGRECONFIG
549 { SIGRECONFIG, "SIGRECONFIG" },
550 #endif
551 #ifdef SIGRECOVERY
552 { SIGRECOVERY, "SIGRECOVERY" },
553 #endif
554 #ifdef SIGRESERVE
555 { SIGRESERVE, "SIGRESERVE" },
556 #endif
557 #ifdef SIGRETRACT
558 { SIGRETRACT, "SIGRETRACT" },
559 #endif
560 #ifdef SIGSAK
561 { SIGSAK, "SIGSAK" },
562 #endif
563 { SIGSEGV, "SIGSEGV" },
564 #ifdef SIGSOUND
565 { SIGSOUND, "SIGSOUND" },
566 #endif
567 { SIGSTOP, "SIGSTOP" },
568 { SIGSYS, "SIGSYS" },
569 #ifdef SIGSYSERROR
570 { SIGSYSERROR, "SIGSYSERROR" },
571 #endif
572 #ifdef SIGTALRM
573 { SIGTALRM, "SIGTALRM" },
574 #endif
575 { SIGTERM, "SIGTERM" },
576 #ifdef SIGTHAW
577 { SIGTHAW, "SIGTHAW" },
578 #endif
579 { SIGTRAP, "SIGTRAP" },
580 #ifdef SIGTSTP
581 { SIGTSTP, "SIGTSTP" },
582 #endif
583 { SIGTTIN, "SIGTTIN" },
584 { SIGTTOU, "SIGTTOU" },
585 #ifdef SIGURG
586 { SIGURG, "SIGURG" },
587 #endif
588 { SIGUSR1, "SIGUSR1" },
589 { SIGUSR2, "SIGUSR2" },
590 #ifdef SIGVIRT
591 { SIGVIRT, "SIGVIRT" },
592 #endif
593 { SIGVTALRM, "SIGVTALRM" },
594 #ifdef SIGWAITING
595 { SIGWAITING, "SIGWAITING" },
596 #endif
597 #ifdef SIGWINCH
598 { SIGWINCH, "SIGWINCH" },
599 #endif
600 #ifdef SIGWINDOW
601 { SIGWINDOW, "SIGWINDOW" },
602 #endif
603 { SIGXCPU, "SIGXCPU" },
604 { SIGXFSZ, "SIGXFSZ" },
605 #ifdef SIGXRES
606 { SIGXRES, "SIGXRES" },
607 #endif
608 { -1, NULL }
609 };
610
611 const char* ret = NULL;
612
613 #ifdef SIGRTMIN
614 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
615 if (sig == SIGRTMIN) {
616 ret = "SIGRTMIN";
617 } else if (sig == SIGRTMAX) {
618 ret = "SIGRTMAX";
619 } else {
620 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
621 return out;
622 }
623 }
624 #endif
625
626 if (sig > 0) {
627 for (int idx = 0; info[idx].sig != -1; idx ++) {
628 if (info[idx].sig == sig) {
629 ret = info[idx].name;
630 break;
631 }
632 }
633 }
634
635 if (!ret) {
636 if (!is_valid_signal(sig)) {
637 ret = "INVALID";
638 } else {
639 ret = "UNKNOWN";
640 }
641 }
642
643 jio_snprintf(out, outlen, ret);
644 return out;
645 }
646
647 // Returns true if signal number is valid.
648 bool os::Posix::is_valid_signal(int sig) {
649 // MacOS not really POSIX compliant: sigaddset does not return
650 // an error for invalid signal numbers. However, MacOS does not
651 // support real time signals and simply seems to have just 33
652 // signals with no holes in the signal range.
653 #ifdef __APPLE__
654 return sig >= 1 && sig < NSIG;
655 #else
656 // Use sigaddset to check for signal validity.
657 sigset_t set;
658 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
659 return false;
660 }
661 return true;
662 #endif
663 }
664
665 #define NUM_IMPORTANT_SIGS 32
666 // Returns one-line short description of a signal set in a user provided buffer.
667 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
668 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
669 // Note: for shortness, just print out the first 32. That should
670 // cover most of the useful ones, apart from realtime signals.
671 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
672 const int rc = sigismember(set, sig);
673 if (rc == -1 && errno == EINVAL) {
674 buffer[sig-1] = '?';
675 } else {
676 buffer[sig-1] = rc == 0 ? '0' : '1';
677 }
678 }
679 buffer[NUM_IMPORTANT_SIGS] = 0;
680 return buffer;
681 }
682
683 // Prints one-line description of a signal set.
684 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
685 char buf[NUM_IMPORTANT_SIGS + 1];
686 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
687 st->print_raw(buf);
688 }
689
690 // Writes one-line description of a combination of sigaction.sa_flags into a user
691 // provided buffer. Returns that buffer.
692 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
693 char* p = buffer;
694 size_t remaining = size;
695 bool first = true;
696 int idx = 0;
697
698 assert(buffer, "invalid argument");
699
700 if (size == 0) {
701 return buffer;
702 }
703
704 strncpy(buffer, "none", size);
705
706 const struct {
707 int i;
708 const char* s;
709 } flaginfo [] = {
710 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
711 { SA_ONSTACK, "SA_ONSTACK" },
712 { SA_RESETHAND, "SA_RESETHAND" },
713 { SA_RESTART, "SA_RESTART" },
714 { SA_SIGINFO, "SA_SIGINFO" },
715 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
716 { SA_NODEFER, "SA_NODEFER" },
717 #ifdef AIX
718 { SA_ONSTACK, "SA_ONSTACK" },
719 { SA_OLDSTYLE, "SA_OLDSTYLE" },
720 #endif
721 { 0, NULL }
722 };
723
724 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
725 if (flags & flaginfo[idx].i) {
726 if (first) {
727 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
728 first = false;
729 } else {
730 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
731 }
732 const size_t len = strlen(p);
733 p += len;
734 remaining -= len;
735 }
736 }
737
738 buffer[size - 1] = '\0';
739
740 return buffer;
741 }
742
743 // Prints one-line description of a combination of sigaction.sa_flags.
744 void os::Posix::print_sa_flags(outputStream* st, int flags) {
745 char buffer[0x100];
746 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
747 st->print_raw(buffer);
748 }
749
750 // Helper function for os::Posix::print_siginfo_...():
751 // return a textual description for signal code.
752 struct enum_sigcode_desc_t {
753 const char* s_name;
754 const char* s_desc;
755 };
756
757 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
758
759 const struct {
760 int sig; int code; const char* s_code; const char* s_desc;
761 } t1 [] = {
762 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
763 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
764 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
765 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
766 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
767 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
768 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
769 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
770 #if defined(IA64) && defined(LINUX)
771 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
772 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
773 #endif
774 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
775 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
776 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
777 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
778 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
779 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
780 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
781 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
782 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
783 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
784 #ifdef AIX
785 // no explanation found what keyerr would be
786 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
787 #endif
788 #if defined(IA64) && !defined(AIX)
789 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
790 #endif
791 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
792 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
793 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
794 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
795 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
796 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
797 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
798 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
799 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
800 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
801 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
802 #ifdef SIGPOLL
803 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
804 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
805 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
806 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
807 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
808 #endif
809 { -1, -1, NULL, NULL }
810 };
811
812 // Codes valid in any signal context.
813 const struct {
814 int code; const char* s_code; const char* s_desc;
815 } t2 [] = {
816 { SI_USER, "SI_USER", "Signal sent by kill()." },
817 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
818 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
819 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
820 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
821 // Linux specific
822 #ifdef SI_TKILL
823 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
824 #endif
825 #ifdef SI_DETHREAD
826 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
827 #endif
828 #ifdef SI_KERNEL
829 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
830 #endif
831 #ifdef SI_SIGIO
832 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
833 #endif
834
835 #ifdef AIX
836 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
837 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
838 #endif
839
840 #ifdef __sun
841 { SI_NOINFO, "SI_NOINFO", "No signal information" },
842 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
843 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
844 #endif
845
846 { -1, NULL, NULL }
847 };
848
849 const char* s_code = NULL;
850 const char* s_desc = NULL;
851
852 for (int i = 0; t1[i].sig != -1; i ++) {
853 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
854 s_code = t1[i].s_code;
855 s_desc = t1[i].s_desc;
856 break;
857 }
858 }
859
860 if (s_code == NULL) {
861 for (int i = 0; t2[i].s_code != NULL; i ++) {
862 if (t2[i].code == si->si_code) {
863 s_code = t2[i].s_code;
864 s_desc = t2[i].s_desc;
865 }
866 }
867 }
868
869 if (s_code == NULL) {
870 out->s_name = "unknown";
871 out->s_desc = "unknown";
872 return false;
873 }
874
875 out->s_name = s_code;
876 out->s_desc = s_desc;
877
878 return true;
879 }
880
881 // A POSIX conform, platform-independend siginfo print routine.
882 // Short print out on one line.
883 void os::Posix::print_siginfo_brief(outputStream* os, const siginfo_t* si) {
884 char buf[20];
885 os->print("siginfo: ");
886
887 if (!si) {
888 os->print("<null>");
889 return;
890 }
891
892 // See print_siginfo_full() for details.
893 const int sig = si->si_signo;
894
895 os->print("si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
896
897 enum_sigcode_desc_t ed;
898 if (get_signal_code_description(si, &ed)) {
899 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
900 } else {
901 os->print(", si_code: %d (unknown)", si->si_code);
902 }
903
904 if (si->si_errno) {
905 os->print(", si_errno: %d", si->si_errno);
906 }
907
908 const int me = (int) ::getpid();
909 const int pid = (int) si->si_pid;
910
911 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
912 if (IS_VALID_PID(pid) && pid != me) {
913 os->print(", sent from pid: %d (uid: %d)", pid, (int) si->si_uid);
914 }
915 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
916 sig == SIGTRAP || sig == SIGFPE) {
917 os->print(", si_addr: " PTR_FORMAT, si->si_addr);
918 #ifdef SIGPOLL
919 } else if (sig == SIGPOLL) {
920 os->print(", si_band: " PTR64_FORMAT, (uint64_t)si->si_band);
921 #endif
922 } else if (sig == SIGCHLD) {
923 os->print_cr(", si_pid: %d, si_uid: %d, si_status: %d", (int) si->si_pid, si->si_uid, si->si_status);
924 }
925 }
926
927 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
928 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
929 }
930
931 /*
932 * See the caveats for this class in os_posix.hpp
933 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
934 * method and returns false. If none of the signals are raised, returns true.
935 * The callback is supposed to provide the method that should be protected.
936 */
937 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
938 sigset_t saved_sig_mask;
939
940 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
941 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
942 "crash_protection already set?");
943
944 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
945 // since on at least some systems (OS X) siglongjmp will restore the mask
946 // for the process, not the thread
947 pthread_sigmask(0, NULL, &saved_sig_mask);
948 if (sigsetjmp(_jmpbuf, 0) == 0) {
949 // make sure we can see in the signal handler that we have crash protection
950 // installed
951 WatcherThread::watcher_thread()->set_crash_protection(this);
952 cb.call();
953 // and clear the crash protection
954 WatcherThread::watcher_thread()->set_crash_protection(NULL);
955 return true;
956 }
957 // this happens when we siglongjmp() back
958 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
959 WatcherThread::watcher_thread()->set_crash_protection(NULL);
960 return false;
961 }
962
963 void os::WatcherThreadCrashProtection::restore() {
964 assert(WatcherThread::watcher_thread()->has_crash_protection(),
965 "must have crash protection");
966
967 siglongjmp(_jmpbuf, 1);
968 }
969
970 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
971 Thread* thread) {
972
973 if (thread != NULL &&
974 thread->is_Watcher_thread() &&
975 WatcherThread::watcher_thread()->has_crash_protection()) {
976
977 if (sig == SIGSEGV || sig == SIGBUS) {
978 WatcherThread::watcher_thread()->crash_protection()->restore();
979 }
980 }
981 }