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